There are two ways to make cold brew coffee. The traditional way is to immerse the beans in cold water and let time work its magic passively. The new way is active extraction; moving water through the beans to actively to extract the flavor compounds from the beans. On the larger scales of commercial coffee production, it just makes sense to move to active extraction to save time, labor and space and to improve the consistency and flavor of your product. The BrewBomb X-45 Brewer and BrewBomb X-60 Brewer are commercial cold brew coffee makers that use a exciting new technology.
Benefits of Active Extraction:
Faster = Brew a complete batch of cold brew (up to 100 gallons) in as little as 2 hours.
Higher Volume = Brew double or triple batches in every shift for hundreds of gallons in 8 hours. If you work multiple shifts, you can double or triple your capacity in a single day.
Tastes Better = Design the cold brew extraction specifically for the flavor profile of your beans. For every roast, you can adjust the grind size, the flow rate, and the extraction time to find your perfect cold brew flavor.
More Consistent Flavor = Once you define your preferred flavor profile, you can replicate the batch every time. Create a consistent product time after time.
Eliminate Filtration = The coffee acts as its own filter bed, trapping all of the particulates in the grounds, keeping it out of the brew. Eliminate the expensive and time consuming step of filtering your cold brew before kegging
Less Labor = The BrewBomb is designed to make spent grounds handling a breeze. Drop the spent grounds into the compost bin as easily as dropping a napkin in the trash.
Less Space = The BrewBomb takes up less than 20 sq. feet of space.
Flexibility = Make large batches or small, depending on your needs.
How it works:
Choose your roast and grind size. Unlike the immersion cold brew coffee method, you can grind all the way down to fine or very fine particle size if you prefer.
Use the control panel to choose your remembered brew profile, or enter the parameters of your brew, including flow rates, and anticipated brew time.
Adjust the spray nozzle to get optimum extraction pattern.
Monitor the cold brew for your brew parameters and flavor, until you are done.
Dispose of grinds, clean and repeat the brew.
If you prefer the traditional immersion method of cold brewing coffee, Stout Tanks and Kettles has a number of options for you, from 30 gallon batches up to 300 gallon batches. Every brewer has their own personal preferences for immersion brewing process. We can provide cold brew coffee equipment with false bottoms to help filter out the first stage of coffee grounds, or we can provide a conical fermentation tank that allow grounds to settle to the bottom of the tank. We can provide tanks with insulation to maintain constant temperature, or we can provide glycol jacketed fermentation tanks that will allow you actively manage the temperature of your tanks to keep your cold brew at your exact temperature.
We can also provide pressure rated tanks that allow you to start the nitrogenation process. Our pressure rated brite tanks and jacketed conical fermenters are designed to accept nitrogen under pressure at cold temperatures which allows your cold brew to nitrogenate more quickly. Most brewers finish nitrogenating in kegs, which we can also provide.
Kombucha brewers have long struggled to keep the alcohol content of their kombucha low. Federal law is clear. If your kombucha EVER exceeds 0.5% Alcohol By Volume (“ABV”), at any point in the production process, you must comply with all Alcohol and Tobacco Tax and Trade Bureau (“TTB”) regulations regarding alcoholic beverages. Compliance can be costly and difficult. You must register with the TTB, get all of your recipes and labels approved, pay all applicable state and federal taxes, and comply with the rules about how your product can be stored, distributed and sold. The only way you can avoid the taxes and regulations is to make sure the ABV is ALWAYS below 0.5%. Most Kombucha brewers want to provide low alcohol products, not only to comply with state and federal law, but also provide pure and healthy kombucha for their customers, who include children, the sick, and the healing. We all want our customers to trust and enjoy our products every time.
For much of the past year, Stout Tanks and Kettles has been working with Bare Bucha, a small Kombucha brewery in Waco Texas that takes seriously the ABV challenge. Toby Tull and David Aycock, the owners of Bare Bucha, conducted over 800 tests of different batches in prototype fermenting vessels manufactured by Stout Tanks in order to figure out how to best produce legal, low-alcohol Kombucha. We were proud to take the stage at Kombucha Kon 2019 in Long Beach California, to share the results with the entire Kombucha community, and introduce our new kombucha brewing vesselThe Symbiosis Fermenter, which makes it easier and faster to brew great Kombucha, and comply with all laws.
Innovating the Symbiosis Fermenter required a return to the fundamentals of fermentation. Kombucha is fermented with a SCOBY, or a Symbiotic Culture of Bacteria and Yeast. Kombucha uses both yeast and bacteria to ferment the beverage. Yeast consume sugars, and in the process create alcohol and carbon dioxide. The bacteria consume alcohol, and in the process, create organic acids, including acetic acid, lactic acid, and gluconic acid. David and Toby realized early on that creating a balanced symbiosis of bacteria and yeast was the key to using nature to keep alcohol levels under the legal limit, and still provide healthy and flavorful kombucha, with all its pro-biotic health benefits. In order to get the symbiosis of bacteria and yeast right, we had to look at the environments we build for fermentation.
First we looked to beer fermentation. Stout Tanks and Kettles conical fermenters are designed to be the ideal environment for just two species of yeasts: Saccharmyces Cervisiae and Sacharmyces Carlsbergensis. Cervisiae (Latin for “beer”) is an ale yeast, which is top fermenting. It prefers to live at the top of the conical fermenter, and performs best between 55 and 70 degrees Fahrenheit. Carlsbergensis is a lager yeast, which is bottom fermenting. It prefers to live at the bottom of a conical fermenter, and performs best between 48 and 55 degrees Farhenheit. Carlsbergensis is named after the Carlsberg Brewery in Copenhagen Denmark, which brews one of the world’s most popular lagers, and which first isolated and identified the lager yeast strain in the early 20th century.
Stout Tanks conical fermenters have several specific design traits to favor these two strains of yeast, and to be absolutely hostile to all bacteria. First, we create a width: volume ratio that makes the tanks perfect for glycol chilling. We use glycol to cool the fermenters to the perfect temperature for either ale or lager yeasts. Second, we create a height: width ratio that allows either yeast to ferment the sugars in the entire tank, whether they are top fermenting or bottom fermenting. Third, we fully enclose the fermenter to eliminate all oxygen. Beyond a quick initial burst of oxygen at the beginning of fermentation. Beer yeasts do not need oxygen to ferment. By eliminating oxygen from there fermenters, we make sure any stray bacteria that require oxygen will die before they can reproduce. (Oxygen also changes the flavor of beer by oxidizing certain enzymes and flavor components in beer). We cap the head space in the fermenter with a shallow domed top. As the yeast ferment the sugars in the beer, the carbon dioxide created by fermentation bubbles to the surface. Because CO2 is heavier than oxygen, it displaces the oxygen through the vent tube at the very top of the fermenter. Finally, the tank itself is constructed to be hostile to bacteria. We use virgin 304 stainless steel, and polish it to a mirror finish, so there are no scratches or imperfections where bacteria can hide. We make every weld sanitary, smooth and polished to eliminate bacteria. The tanks are designed to drain smoothly and evenly, so a Clean In Place program of caustic rinses followed by acidic sanitizing rinses will kill any bacteria on any surface.
It’s clear that beer fermenters are not the best environment for a symbiosis between yeast and bacteria. They are very yeast friendly and bacteria unfriendly. Yet most Kombucha brewers we surveyed used some beer fermenter or modified cylindrical beer fermenter for their Kombucha.
Next we looked at a very specific kind of tank that is designed for one of these two species of yeast. A lagering tank is designed specifically for the bottom fermenting lager yeast. It takes the traditional vertical orientation of a conical fermenter and turns it on its side. This shape provides more bottom volume for the Carlsbergensis yeasts to thrive.
But the lager tank maintains many of the antibacterial properties of its vertical cylindrical cousins: mirror polished stainless steel, sanitary welds, oxygen free environment.
We also looked at wine fermentation. Stout Tank also sells a complete line of red and white wine fermentation tanks. Wine is primarily fermented by the same yeasts that ales are: Saccharmyces cerevisiae. As you would expect, wine tanks create a similar environment to beer tanks. Our variable capacity, or “floating lid” wine tanks are a vertical cylinders, made from virgin stainless steel. They have a similar width to volume ratio to allow of efficient glycol cooling. Controlling oxygen is even more important with wine because of the oxygen sensitive compounds in wine. The lids float directly on the surface of the wine eliminating entirely any airspace above the wine. Wine is more acidic than beer, so the polish on a wine tank is less crucial than on a beer tank, so the finish on a wine tank is a bright annealed finish. The steel is thinner because it does not need to be polished so extensively. But wine fermenters, like beer fermenters, are designed to be heaven for yeast, and hell for bacteria.
When Toby Tull and David Aycock started Bare Bucha in Waco Texas, they were unapologetically pro-probiotic. They loved the health benefits that kombucha offered, full of healthy bacteria and organic acids. But they were also committed to following the rules, and creating a product that proudly complied with all rules. They wanted to use nature itself, and the symbiotic power of the community of microbes in Kombucha. They did not want to dilute their kombucha with water before bottling to meet the 0.5% ABV requirement. That does not comply with the law. They did not want to rely on million dollar machine to remove the alcohol with an industrial distillation process. The very brand of Bare Bucha indicates a simple, pure, unadulterated beverage. Industrial processes go against their very brand. Industrial distilling is not consistent with the small-business, craft ethos of Kombucha in their minds. The also did not want to pasteurize their Kombucha at any point in the process in order to kill the yeast before they could create more alcohol. Killing the yeast with pasteurization removes the very biotics that make Kombucha pro-biotic.
Conventional wisdom dictated that out of the three components of 1.) ABV, 2.) Taste, and 3.) Pro-biotic quality, Kombucha brewers could choose any two. David and Toby were not satisfied with the conventional wisdom. They were committed to finding a natural way to harness the power of symbiosis to create a pro-biotic, low-alcohol, and great tasting Kombucha. In the course of their quest, they learned that SHAPE MATTERS.
Together with Stout Tanks and Kettles, we developed a new shape of fermentation vessel especially for Kombucha. We changed the shape to not only to allow bacteria work in symbiosis with yeast in the Scoby, but to allow the symbiosis to actually favor the bacteria. The bacteria primarily responsible for consuming the alcohol are Komagataeibacter species, which require oxygen to metabolize alcohol. So we created an open top fermenter to allow access to oxygen. The Komagataeibacter bacteria ferment best on the surface, so we created a shallow pan that allowed lots of surface area for the bacteria to thrive. The bacteria perform best in temperatures above 80 degrees Fahrenheit, so we created a single walled pan that allows the Kombucha to absorb heat from the surrounding air. Brewers can control the heat by increasing the ambient temperature of the room.
Stout Tanks and Kettles and Bare Bucha collaborated on this innovative new design, and Toby and David thoroughly tested the fermenter with over 800 tests. They used the Rida-cube alcohol and sugar tester provided by r-biopharm to scrupulously test the ABV, sugar, and acetic acid content of their Kombucha throughout the fermentation.
In the course of their tests, Bare Bucha found that fermentation in traditional cylindrical shaped fermenters favors the alcohol producing yeasts. Kombucha yeast is primarily Brettanomyces species, which are not present in beer, and are usually associated with off-flavors of wine. These yeasts start consuming sugars and creating alcohol long before the bacteria can get going. The shape of the traditional fermenter means that the bacteria are always behind the curve. In this summary of hundreds of fermentation tests in traditional fermenters you can see that the yeast start fermenting early reducing sugars, and creating alcohol. The bacteria take much longer to start consuming alcohol and creating acetic acid.
When testing the Symbiosis™ Fermenter, we found the bacteria were able to get ahead of the curve, and start consuming alcohol before it exceeded the legal limit, and creating more acetic acid sooner. The result was that Bare Bucha was able to reach their desired flavor profiles more quickly, with the same levels of organic acids as produced in a traditional fermenter, but never exceed the legal limit for alcohol. Bare Bucha was able to achieve its desired flavor profile after only 14 days of fermentation in a Symbiosis Fermenter. In a traditional fermenter, it takes over 40 days to get the alcohol levels and organic acid levels to the proper result. This allows Bare Bucha to use less sugar and less time to achieve the same flavor and pro-biotic result.
This is a significant step forward in commercial kombucha fermentation.
Limited only by the imagination and needs of the brewer, hop backs are a versatile addition to any nano brewery, micro brewery or brewhouse. Hop backs give your beer fresh hop nose and flavor without significantly affecting bitterness. They are a great way to improve the flavor and character of your brews.
Our Hop Backs are a great way to infuse your beer with fresh hop aroma and flavor without significantly adding bitterness. Most of our brew kettles have whirlpools and trub dams to collect hops and trub in the brew kettle. Still, many brewers like to run the wort through a hop back after the boil to give their IPA’s and pale ales that amazing hop character.
A half ounce of hops per gallon of wort in a nylon or muslin bag inside the hop back will give your beer that fresh hop nose, and filter for your wort, keeping the hops and trub in the Hop Back and out of your filter, wort chiller or fermenter. When wort cools in the brew kettle, eventually it will reach the perfect temperature to release the hop oils without isomerizing
them. Experiment with the type and the amount of hops and the temperature of the wort to find your sweet spot. Choose the right size hop back for how hoppy you want your IPA.
Some brewers use hop backs between cold side transfers as well, between the conical fermenter and the brite beer tank. Different hop flavors and aromas emerge at lower temperatures.
Hops aren’t the only thing to infuse. Hop backs can be used to infuse oak chips, coffee, chili peppers, vanilla beans, just about anything you can think of to add to your beer.
Our hop backs also work great for yeast cropping or storage. When you drain yeast from the conical fermenter, you can collect and store your yeast right in the hop back because it iss a completely sanitary, closed vessel. For your next batch, you can pitch yeast directly from the hop back into your fermenter.
Like all of our tanks and kettles, our hop backs use only sanitary fittings and hardware and are made from virgin 304 stainless steel.
Here are some examples of how brewers have used hop backs in their breweries:
HOP BACK – whole flower hops during hot side knockout. Use a hop sack with whole leaf hops. It is easier to clean up
INFUSER – used either during hot or cold side applications using spices coffee, fruit, blending; this vessel can be purged and contents scrubbed with CO2 to reduce dissolved oxygen pickup. Infuse that amazing hop character into your IPA’s and pale ales.
YEAST BRINK – give this vessel a good cleaning and remove the false bottom; fill it with yeast and use it like any other brink.
CIDER BACK SWEETENING – fill with your desired amount of back sweetening; scrub with CO2 and purge the vessel; Use the pressure to transfer to a tank of cider.
2nd MASH TUN – great for sour mash or adding a secondary mash to bump up gravities on large-gravity beers. ▪ OPEN-TOP WILD FERMENTATION VESSEL- great for sour / wild open-top fermentation that can be wheeled into a cooler for post fermentation.
SOLO BLENDING / BRITE TANK – blend small batches for experiments. Carbonate small batches. Wheel into cooler and carb for small-batch one-offs.
BARREL TOP-OFF TANK – bring your top-off liquids to the beer, wine, spirit, cider barrel,or blending tank across the brewery for pressurized top-offs, blending or transfers.
CIP – holds caustic or sanitizer for CIP loop. Easy mobility makes your brewery safer and more efficient.
We sell a number of different sized hop backs perfect for home brewing, micro breweries or nano breweries.
Peristaltic pumps are a type of positive displacement pump – they are excellent sanitary pumps for beverage applications because they allow you to precisely measure the amount you pump, are easier on the product than other types of pumps
How do they work?
Peristaltic pumps work on the same principle as muscles that move food inside living beings. Rollers squeeze a tube in a repeating pattern to pull and push the material through tubing.
What Are the Benefits to Using These Pumps?
You are able to dose precise amounts of liquid using a flow meter and peristaltic pump – for example: if you want to pump 8 gallons of liquid simply turn the pump on until 8 gallons is dispensed and then turn it off – no backflow to deal with and precise pumping every time.
Purgeable – you can purge oxygen from the pump to only allow inert gas or CO2 to contact your product.
Sanitary – only the internal hose touches the product being pumped.
Closed loop – peristaltic pumps isolate the product in a closed loop so it isn’t exposed to air, potential contamination and/or oxygen.
Why choose peristaltic over centrifugal?
Both stainless centrifugal and peristaltic pumps have sanitary design but where precise measurements are required, nothing beats a peristaltic pump.
Peristaltic pumps are self-priming so they can be a great choice where priming isn’t possible.
Reduce shear on your product – peristaltic pumps are gentler on produce and can reduce shear.
Using hops in the hot side brewing process has been a driving force behind so many different styles of beer in recent years. With the rise of the IPA, the quest for the perfect balance of bitterness, aroma and flavor have led to many changes in both brewing equipment and brewing processes in breweries, especially in small breweries dedicated to developing new flavor experiences for their customers.
For many years, brewers battled to see how bitter they could brew an IPA. Heavily-bittered beers required not only large amounts of high-alpha hops throughout the boil, but then even more hops at whirlpool. After the whirlpool, brewers would use a hop back with whole flower hops to add flavor and aroma while helping to filter out trub from the wort during transfer to a heat exchanger.
A few years back the whole process was uprooted again as consumer palates gravitated to IPAs with lower bitterness and more hop character, especially fruity and tropical flavors. Brewers are now using less hops earlier in the process and focusing on the whirlpool or another separate vessel to extract the desired hop flavors. “Hop Standing” became a regular process for many brewers. “Hop standing” refers to adding hops at the conclusion of the boil, after the flame, steam or electric elements have been turned off, and allowing the wort to stand in the kettle for the perfect time to extract the magic flavor and aroma while limiting isomerization of alpha acids (bitterness).
Another method to extract even more flavor and hop oil involves using a lower temperature to reduce isomerization and retain hop oils. Brew a slightly higher gravity wort and add back cooler water. Try 140-150 degrees depending on the amount of cooler water you add to reach your final gravity before whirlpool. After whirlpooling and the liquid homogenizing your temperature should still be well above the pasteurization temperature. (160 degrees). Your wort will be ready to transfer to a fermenter with all that lovely hop character.
Whether you need a hop back to filter your heavily hopped wort, a slightly larger vessel for high gravity brewing or a specialized heat exchanger to cool your wort for optimal hop oil extraction, know that the craft brewery experts at Stout Tanks and Kettles can provide solutions to all your brewery needs.
Take a look at some of the products mentioned in this post:
The only way to get that beautiful lingering fresh grain flavor of authentic continental (German) lagers is to radically reduce the amount of dissolved oxygen in your brew. For my first brew on our new Low Ox system, I brewed a Munich lager, using high quality German malts. I wanted to preserve as much of that fresh grain flavor in the beer as possible. Malts naturally contain an enzyme in called Ascorbic Acid Oxidase (AAO), which is very sensitive to oxygen. Exposure to oxygen will destroy AAO, and with it that amazing flavor in the malt we are trying to preserve. At Stout, we’ve been engineering low oxygen home brew systems with the goal of having zero oxygen in the brew. I recently made my first batch of beer using the Stout Tanks and Kettles’ 20 Gallon low oxygen brewing system. Unfortunately for me, I did not introduce enough oxygen in this particular batch. Read on to find out how that is even possible
Prepare the Hot Liquor Tank.
I prepped my hot liquor by preboiling the water and purging the head space with carbon dioxide. Boiling evaporates almost all of the dissolved oxygen that is in the hot liquor. Using the convenient gas fittings on the hot liquor tank, I purged the head space with CO2 to make sure no oxygen can re-dissolve into the hot liquor. I also bubbled CO2 up from the bottom gas inlet just to keep a positive pressure in the hot liquor tank so no oxygen could get back in. I have a gas manifold and check valves at the tank so I just open the appropriate gas valve when I want to purge the tank.
I cooled the hot liquor to 200F by running cold tap water through the HERMS coil (Heat Exchanged Recirculating Mash System) while simultaneously recirculating the hot liquor through the tangential inlet. We include tangential inlets on our hot liquor tanks to prevent temperature stratification. Hot water rises, so if you don’t circulate, you will end up with different temperature water at different levels in the tank, which will affect your mash temperatures.
Because I wanted to make sure I could eliminate all the oxygen from the brew, I added enough Sodium Metabisulfite (SMB) to get 35 ppm in solution. SMB absorbs dissolved oxygen chemically (hint). I also added Brewtan B because I don’t have an RO system. In order to ensure that no oxygen was re-introduced into the hot liquor throughout the HLT preparation and mash, I periodically purged the head space and bubbled CO2 from the bottom gas inlet. Using the built-in sample valve on the HLT, I used sulfite test strips to confirm that I still had the amount of SMB I wanted in solution. Then I quickly cooled the HLT down to strike
To prepare for mashing, I installed a nylon mash bag in the mash tun using the 4 conveniently mounted hooks built right into the inside of the kettle. Then I placed my malt mill on top and purged oxygen from the tank with CO2 from the bottom inlet to displace as much oxygen as possible. Then I milled in my conditioned malt, while simultaneously flowing CO2 in through the bottom inlet in order to keep the O2 out. The mash bag allows me to run my vorlauf and HERMS at high flow rates without worrying about a stuck mash. My grains fell right into the mash bag.
After the grains were milled, I installed the vorlauf pipe, sparge arm, and strike water hose, which runs down to the bottom of the tun. After milling in, I quickly placed the lid on top and then installed the lid clamp, and continued purging the tank with CO2 for a short time. All 3 kettles have a VPRV (vacuum/pressure relief valve) and also a ¼” ball valve in the lid – I opened the ball valve whenever purging the kettle with CO2, which I did frequently throughout the mash.
Time to start brewing. Once the grains were milled, I made a point to mash in within 15 minutes to prevent oxidation of the grains – you are not guaranteed to get oxygen gas completely out of the milled grains when they are dry. I filled the mash tun from the bottom up, slowly, so I would not need to stir the grains too much. After the exact amount of water was added, I removed the 3” tri clamp cap, turned on the CO2 for a head space purge, and gave the mash a gentle stir. I don’t think the stir was actually necessary, but I’m glad I did it, because I noticed that there wasn’t enough water in the mash tun. Why would that be? Because of the mash bag – the grains did not push the mash bag out to the full diameter of the kettle, so the grains were higher than they normally would be (there was a gap between the mash bag and the edges of the mash tun). So, I had to add more water, and next time I will have to assume a higher water-to-grist ratio for my 5 gallon batches. After filling the tun with enough hot liquor, I replaced the 3” cap and purged the head space some more. Then, I used the convenient sample valve on the mash tun to grab a sample of the wort to test for SMB. The color on the test strip was the same as the HLT water, between 25 and 50 ppm (the scale is 0, 10, 25, 50, etc.). This means that I didn’t add any measurable oxygen to the water or wort yet; if oxygen is present, it consumes the sulfites and then the sulfite measurement will drop. So, no drop in sulfites means no oxygen was added. That’s great!
During the mash, I did a rest at 145°F and then pumped the wort through the HERMS coil in the HLT to raise the mash temp to 156°F. The vorlauf pipe is a nice addition that returns the hot wort under the surface of the mash and it spreads the wort across the mash to ensure an even flow (i.e, no channeling). Because of the mash bag, I can run the vorlauf at a fairly high rate, which helps keep the temperatures even throughout the mash tun and also speeds up the ramp. After the 2nd rest, I bumped the mash up to mash-off temperatures. As a quick side note, I generally set the hot liquor tank about 10° higher than the desired mash temp when using the HERMS. I monitor the temperature gauge on the outlet of the HERMS coil to prevent overheating the wort. The flow rate and HLT temperature both affect the output temperature. A final test of the sulfites showed it was still between 25 and 50 ppm. Woo hoo! Still no added oxygen.
I again used the sample valve to get wort samples for my iodine tests for conversion. There was no need to open the mash tun throughout the process, other than opening the ¼” ball valve for venting while I was purging the head space with CO2.
I sealed the brew kettle except for the 3” cap on the lid and purged with CO2 from the bottom gas inlet before starting the runoff and periodically repeated the purging using the upper gas inlet throughout the mash runoff. My two peristaltic pumps transfer wort out of the mash tun at the same rate that they add sparge water. Since the Mash Tun is closed except for the ¼” ball valve and I am keeping CO2 in the headspace, I’m not worried about the water splashing inside the mash tun. You can’t oxygenate the wort through aeration if there is no oxygen in the atmosphere. Speaking of that, on a safety note, I made sure I have plenty of fresh air coming into my brewery since I was frequently adding CO2 to the kettles. My beer doesn’t need oxygen, but I certainly do.
At kettle full, I did yet another SMB test and got another reading between 25 and 50 ppm. Still no oxygen absorbed. The brew kettle has its own sample valve, so grabbing a sample was quick and easy without having to open the kettle. I like to turn the heat up to 200 – 205°F on my brew kettle during runoff so that I don’t have to wait around for wort to start boiling when the runoff is done.
At kettle full, I set the brew kettle temperature to 215°F to get a boil going. I figure out how many gallons I need to boil off, and use that to figure out what percent of full power to set for the elements. Brag alert: All of the electric heating control panels we provide include the ability to adjust the heat of the elements. Many other systems (commercial and homebrew) cannot do this. You can download a handy spreadsheet from our website to calculate the power you need to provide to your elements to get your desired boil rate. To avoid heat stress, I set a low evaporation rate and tried to keep the total boil time under 70 minutes. By using high quality German malts, I can get away with a lower evaporation rate than normal. With a wort pH of ≥ 5.4, and using high quality German Pilsner malt, the evaporation rate can be as low as 4% to 6% per hour. Because I did not have an aggressive boil, I only removed the 3” cap and left the lid otherwise closed. At first, though, I cranked up the heat percentage to get to a boil faster. You can guess what happened next – a boil-over! Fortunately, I noticed it right away just as the foam was rising out of the 3” TC port and cut the heat. The overflow stayed right in the lid and was easy to clean up – lucky me.
I reset the heat level for the elements and restarted the boil. During this time, I cleaned out the mash tun, which was really easy. I removed the lid clamp and lid, and lifted the mash bag out and dumped the bag of grain into a wooden bucket for delivery to a nearby farm for their goats and chickens. There was minimal residue under the false bottom. And, it was a lot easier than scooping the grains out.
After the boil was done, I took another sulfite test and the levels were still at 25-50 ppm. Amazing – I didn’t expect that. I did my normal whirlpool routine in the brew kettle using the built-in tangential inlet, and pumped the wort into my trusty 7.3 gallon stainless steel conical fermenter. I still use the very first conical fermenter we ever produced. Another sulfite test and I got the same results. This means that I made a batch of beer and introduced practically NO measurable oxygen throughout the entire hot side process. I was really happy about that. Our products work extremely well. Maybe too well, because here is where things went a little bit sideways. Not too bad, but enough to affect the final result.
I thought I would be able to get the wort down to my pitch temperature of 42°F by chilling my tap water further by filling the hot liquor tank with ice and water and running my tap water through the HERMS coil in the hot liquor tank after passing through my all stainless steel counter-flow chiller. I hadn’t tried it before, and I paid the price for my guess. It dropped the temperature, but not nearly enough. I got my wort down into the 60’s (°F). So, I turned on the peltier coolers on the fermenter and waited an hour, but I could wait no longer. This is a delicate moment in low oxygen brewing. The yeast need some oxygen in the wort for the first phase of their growth cycle, but we don’t want too much exposure to oxygen to destroy the AAO enzyme and ruin that beautiful lingering fresh grain flavor in my Munich Helles malt. Fermentation needs to start within 6-8 hours in the fermenter in order to prevent oxidation at this stage.
I pitched my 2 liter yeast starter and then oxygenated the wort using my wand for about 60 seconds. Normally, I oxygenate for 20-30 seconds for a 5 gallon batch, but because of all the sulfites still in the wort, I decided to oxygenate longer to make sure that the sulfites didn’t steal all of the O2 from the yeast. I did another sulfite test and the measurement was still near 25 ppm. So, I oxygenated for another 60 seconds or so and tested again. The sulfite levels hadn’t noticeably dropped. I repeated this one more time, then decided enough was enough. I sealed the fermenter and let nature take its course. I concluded that the SMB and yeast would have to fight it out for all the oxygen I introduced.
At this point, I started to suspect that my sulfite test strips were defective, because they were showing so little oxygen uptake. I couldn’t believe our system worked so well keeping oxygen out. So, I took a sample of fresh water and tested that. It read 0 ppm, so I concluded the test strips were just fine. Later on, I conferred with Bryan Rabe at the low oxygen brewing website and he confirmed that he measured < 0.1ppm total O2 uptake using his Stout Tanks and Kettles’ low oxygen system. He’s got a DO meter and can check it more accurately than I can.
The bottom line is that it ended up taking almost 24 hours for the fermentation to start, which meant that the oxygen I added to the wort had ample time to do its evil work. I performed the remaining steps according to plan, but the damage was already done. The beer is actually really good, but it lacks the lingering, fresh grain flavor I covet.
So, why did I say that I didn’t add enough oxygen to my brew at the beginning of this blog? Because I added 35ppm of SMB thinking that my process would be adding oxygen that needed to be “consumed” by the sulfites. But, our low oxygen tanks did their job and the process didn’t add any measurable oxygen to the wort, which left a lot of sulfites hungry for oxygen. I tried to compensate by adding extra oxygen when I pitched, but I probably didn’t add enough satisfy the sulfites and to get the yeast going quickly enough. While the wort was in the fermenter, it had enough time to absorb enough oxygen to destroy the Ascorbic Acid Oxidase (AAO) and the lingering fresh malt flavor it provides. The better solution to this problem will be to trust our low ox equipment, and not add nearly so much SMB, if any at all. That way when I oxygenate the wort, the yeast will have enough oxygen to quickly replicate and consume the oxygen before it can destroy the fresh lingering grain flavor I am after.
So, here are my takeaways after brewing my first batch with my Stout Tanks low oxygen brewing system:
Trust the equipment. It is designed to keep oxygen out of the entire brew process.
Don’t add any Sodium Metabisulfite, or add very little (perhaps a few ppm only). It’s better to keep the oxygen out than it is to absorb it with SMB.
Larger yeast starter. Use a 3 liter starter to ensure that the batch takes off faster. I realized too late that my starter wasn’t going to be big enough, and hoped for the best. Hope is not a good strategy.
Give us a call if you would like to learn more about low oxygen brewing. We would love to talk with you about how you can start your own low ox brewery.
Part of the magic of Kombucha is the flavor of the tea. Kombucha brewers will use different varieties of tea, and brew it in different strengths. Most kombucha brewers like to have the water temperature of their tea to be slightly below boiling point to get the best flavors. Once the tea has fully steeped, most brewers like to add sugar to their tea while it is still hot. Why? Because it is easier to dissolve sugar in hot water.
Stout Tanks and Kettles sells brew kettles heated by electricity, steam, natural gas or propane. Energy efficiency is a big priority for us, and getting your water hot when you need it is important. Many of our electric brewing systems come with controls that can heat the water on a timer so that your brew day can start early. Some brewers like to boil their water for a while first to evaporate off the chlorine that many municipalities add to the water. The chlorine can affect flavor and kill some of the beneficial bacteria in your SCOBY.
Most brewers will brew a highly concentrated tea, and then dilute it with cold water to bring the temperature down to a range that will be comfortable for the SCOBY. Depending on the volumes of your brew, it may be necessary to use a counter flow chiller, a plate chiller or other heat exchanger to bring the temperature down quickly. Heat exchangers allow you to recapture the heat of your tea and use it to brew another batch, increasing your energy efficiency, lowering your carbon footprint and increasing the amount of Kombucha you can brew in a day. A heat exchanger allows you to quickly get your tea down to the optimal temperature for your particular SCOBY.
Bacteria and Yeast thrive in slightly different temperatures. Bacteria like it cooler. Yeast like it warmer. The temperature range to make them both happy is between 78º and 82º F. If you can control the temperature in your fermentation vessel, you can favor either side of the symbiosis. If you want to favor the bacteria, drop the temperature a few degrees. The bacteria will generally be active between 65º and 80º F. If you want to favor the yeast, raise the temperature of the Kombucha between 75º and 85º F.
Many of our fermenters are jacketed, which means that the tanks are wrapped in a stainless steel jacket that allows you to pump cooled or heated glycol around the tank, which allows you to control the temperature inside the tank. Home brewers will often rely on the air temperature of the room where they brew Kombucha to control the temperature of fermentation, but at larger volumes its just not possible to control the liquid temperature of the Kombucha by controlling the air. At commercial scale, it is just more energy efficient to directly cool or heat the liquid.
In most fermenters, yeast usually gain the upper hand. They are first in the fermentation process, and fermentation actually releases heat, further encouraging the yeast over the bacteria. If the yeast get the upper hand in your SCOBY, they will produce more alcohol than the bacteria can digest. This can make it hard to maintain the flavor profile you want, and to get the alcohol by volume (ABV) down to legal limits. Your SCOBY will become dominated by yeast over time, leaving the bacteria weaker. In most breweries, a glycol chiller will help keep your Kombucha at the perfect temperature.
We also can provide complete automation of your brewery, from controlling the heat in your tea brew kettle, to maintaining the temperature in your fermenters, and running the pumps that move your Kombucha from brew kettle to fermenters to your bottling or kegging system.
Many homebrewers have tried to create lagers with that “true German flavor” but never actually achieved it. Another way to describe the elusive taste is “fresh, lingering grain flavor”. Brewers try decoction mashing, triple decoctions, melanoidan malt, flaked barley, and so on without success. If you want to make authentic continental lagers, then a proven method is to eliminate oxygen from your brewing process starting with your brewing water and unground malt and ending with wort in the fermenter with less than 1 ppm of dissolved oxygen. This is called Low Oxygen Brewing.
There is a lot of information about Low Oxygen Brewing on the internet, so we won’t repeat it here. Suffice it to say that it requires keeping the dissolve oxygen below 1 ppm throughout the entire brewing process in order to preserve the fresh, lingering grain flavor so it gets all the way into your beer.
At Stout Tanks and Kettles, we have partnered with the Low Oxygen Brewing team to develop a brewing system that gives you the ability to practically eliminate oxygen pickup.
Here are the features of the Low Oxygen Brewing System, kettle by kettle.
Sealable lid to keep oxygen out of the kettle during the brew, with 2-4 psi pressure capacity.
(4) upper hooks hold a mash bag (not included) to allow fast vorlaufs without getting a stuck mash and super easy and fast cleanup – just lift the bag out and empty the grains into your disposal bin.
Lower CO2/N2 gas inlet for purging tank of oxygen.
Upper CO2/N2 gas inlet for purging tank of oxygen.
Sample valve for sampling and testing wort during the brew without introducing oxygen into the kettle.
(4) recirculation fittings at top of mash tun so you can connect your strike water hose, sparge arm and vorlauf pipe, then seal the mash tun and leave it closed until you are done mashing (the 4th fitting is for your upper CO2/N2 gas inlet).
Lid port for venting CO2/N2 when purging.
Lid port for pressure relief valve.
3” TC lid port for viewing the mash, venting and adding additives with the lid on.
Bottom drain outlet maximizes drainage and improves mash tun performance.
All TC ports and fittings with (2) 1” butterfly valves.
(2) stainless steel bars for neatly mounting your pump underneath the kettle (kettles with legs).
Sealable lid to keep oxygen out of the kettle during the brew, with 2-4 psi pressure capacity.
Lower CO2/N2 gas inlet for purging tank of oxygen.
Upper CO2/N2 gas inlet for purging tank of oxygen.
Sample valve for sampling and testing wort during the boil without introducing oxygen into the kettle.
Lid port for venting CO2/N2 when purging.
Lid port for pressure relief valve.
3” TC lid port for venting and monitoring kettle with lid on.
External sight glass allows you to monitor water level without opening the kettle.
Tangential inlet with 1” TC butterfly valve for whirlpooling wort at the end of the boil.
5” tall trub dam to keep hops and trub out of your fermenter.
Conical bottom to keep more hops and trub in the kettle and out of your fermenter.
Wort outlet with 1” TC butterfly valve.
Bottom cleanout port with cap for easy draining and cleaning of the kettle.
Ports for your element, float switch, and thermowell (thermowell is included with kettle).
All TC ports and fittings with (2) 1” butterfly valves.
(2) stainless steel bars for neatly mounting your pump underneath the kettle (kettles with legs).
Our Low Oxygen Brewing Systems (LODO) are currently THE ONLY QUALITY LOW OXYGEN KETTLES ON THE MARKET. These low oxygen brewing systems provide the ability to seal off oxygen from water and wort, and also minimize oxygen uptake throughout the brewing process.
Improve the overall quality, flavor, and freshness of your beers, even IPAs
Preserve the fresh malt flavor
Obtain the lingering fresh grain flavor you only find in fresh Continental style
By properly using the provided CO2/N2 purge ports, pre-boiling your hot liquor, purging or flushing your hoses, spunding your beer, etc., you can eliminate the use of Metabisulfite in your brewing process and achieve sub 0.1ppm dissolved oxygen levels.
It costs a lot of money to open a brewery, and you might ask, “Do I really need to spend all that money?”.
Some brewers look for immediate savings is in the brewhouse by eliminating a hot liquor tank. Do you need a 3-vessel brewhouse, with a mash tun, brew kettle and a hot liquor tank? Or can you get by with a 2 vessel brewhouse, just the mash tun and the brew kettle? Some people claim that the hot liquor tank (or “HLT”) is just a glorified hot water tank anyway, and you can brew beer just fine without it. Other’s claim that the hot liquor tank is an essential part of their brewing process, and it would be hard to brew without it.
So, can you get buy without a hot liquor tank? The answer, of course, depends. There are plusses and minuses. Tradeoffs must be considered before decisions are made.
One common strategy to replace the HLT is to install an on-demand water heater, otherwise known as a tankless water heater. The up-side of an on-demand water heater is they can be very efficient at heating water. Most of them run on natural gas and are almost or over 90% efficient with their energy. Because natural gas is a low-cost source of energy, the cost of raising the temperature of your strike water from ground temperature to your mash-in temperature can be every economical. So getting hot water from a tankless heater can be pretty cheap.
By eliminating the HLT from your brewhouse, you have saved the cost of one vessel, which can be a significant investment. But what are the down-sides? What do you give up when you eliminate the hot liquor tank?
One of the big things you give up is time. Many tankless water heaters are limited in the volume of hot water they can produce. When mashing in, it can sometimes take quite a while for a tankless heater to reach your strike temperature. The higher the temperature you need for your strike water, the longer the tankless water heater will hold the water in the heat exchanger. Tankless water heaters will reduce the flow of water until the water hits the target temperature. Depending on your starting groundwater temperature, the actual gallons per minute (GPM) of your tankless water heater can be significantly below the stated rate.
At 4 gallons per minute, it will take almost 25 minutes to fill a 5 BBL mash tun completely. How long does your mash last, and how long will it take to fill the mash tun?
Another thing you give up is precision mashing. Many of our brew houses come standard with HERMS coils. HERMS stands for Heat Exchanged Recirculating Mash System. With a HERMS coil you recirculate your wort through a heat exchanger coil in the HLT. You can precisely control the temperature of the mash by how quickly you recirculate the wort through the HERMS coil, and by how hot you keep the water in the HLT.
Some brewers like to step mash. Step mashing is raising the temperature of the mash in stages. This is much easier with a HERMS coil in your hot liquor tank because you can precisely control each step of the mash. This is hard to do with a tankless water heater that has only a single temperature setting.
Another tradeoff is volume. Many brewers opt for an oversized HLT simply because it is handy to have a lot of hot water around for clean up, especially if you are using a CIP cart. The pump on your CIP cart drawing from an HLT can give you a large volume of hot water fast. Sometimes faster than any water heater can.
An electric HLT can also provide convenience. With a Stout Tanks and Kettles electric brewing system, it is possible to set your HLT on a timer so it can start heating your water overnight while you sleep. Your HLT can be automatically making hot water while you are still at home making your coffee. You can show up in the morning to hot strike water, ready to brew beer.
HLT’s can also save energy. At the end of your boil, when you run your beer through the heat exchanger on the way to the fermenter, you can put all of that heat back into your HLT for your next brew. For those brewers that double batch, or brew back to back days, this can save a significant amount of energy. Heating your strike water can be almost half of the energy you use in your brewery.
Finally, and HLT makes it easier to treat your water for Ph, minerality, chlorine and other impurities. For brewers who treat their water, the HLT can be very helpful.
So in the end, whether you build your brewhouse with 2 vessels or 3 is really about your personal preferences. Many great beers have been brewed without a hot liquor tank. And for cash strapped start-ups, getting started can be better than waiting until you can afford the perfect brewery. But if you can afford it, the HLT can make your brew days easier and more enjoyable, and help you make great beers.