Craft Brewery Experts


(The following is a first-person narrative from Stout Tanks and Kettles’ owner John Watt.)

A HERMS coil in a hot liquor tank is a useful tool for maintaining and increasing mash temperature, providing the ability to maintain consistent temperatures during the mash, but also providing the ability to step mash without infusions and without overheating the wort. We have found that they are useful at both the homebrew and nano/microbrew scale.

What is a HERMS coil? Heat Exchange Recirculating Mash System coil; or simply, it is a coil of stainless steel tubing placed into a hot liquor tank. It can be either built-in, with connections going through the hot liquor tank wall, or the coil can be just set into the hot liquor tank. Electric HLT’s normally require that the coil be positioned above the heating elements; therefore, the electrically heated HLT HERMS coil is raised.

I am going to share my experience using my HERMS coil. I use mine with every brew now, and it makes brewing so much easier and I believe, makes for better beer. Why? Because I am able to maintain mash temperatures within a small range, and I am able to quickly do step mashes without overshooting or undershooting my target temperatures. Hitting and maintaining your temperatures in brewing is one of the biggest factors to making better beer.

I hope this information provides solid guidance to you, but you should also know that your experience may be different for all kinds of reasons.


When I am raising my mash temperature, I have found that I can set the hot liquor tank to 5 degrees Fahrenheit above my target temperature while I run the HERMS and get a good result. With this, I get a nice, relatively quick temperature rise in the mash tun. I change the HLT setting right when I start the mash step-up with the wort running through the HERMS coil, so that the hot liquor tank temperature is rising at the same time as the mash tun.

I like this because it is not neutralizing the mash enzymes unnecessarily. For example, if I were to raise the HLT to 10 degrees F above the mash then the wort coming out of the HERMS coil will be that much hotter. This will cause more enzymes to be neutralized; the very enzymes I want to be active for the mash.

This temperature setting will vary based on the flow rate of the wort going through the HERMS coil, fill height in the HLT, and volume of the mash. Faster flow rates mean less heat will be transferred and thus higher temperatures may be needed. Conversely, slower re-circulation rates will mean more heat transfer and lower HLT temperatures may be needed. You should experiment with your system and your pumps as each system is unique – knowing your system is a part of the brewer’s journey.

I also use the HERMS coil to maintain mash temperature. This is a very easy way to keep the mash temperature constant for long step mashes when making traditional lagers, for example. I have found that when I am maintaining temperature, I only need to keep the hot liquor tank about 3°F above the mash temperature. If your mash tun is insulated, you may use similar or lower temperature settings on HLT. Insulated tanks will hold temperatures steady longer than tanks without insulation. Again, these parameters will change based on your system, the batch size, flow rates, coil dimensions, etc., so you need to experiment on your system.

Over the years, at Stout Tanks and Kettles we have increased the coil diameters and lengths of the built-in HERMS coils in our hot liquor tanks to improve efficiency and speed. While the old coils were able to get the job done, now they do it faster and better than in the early days. We constantly strive to improve designs based on real world experience.

In summary, a great way to improve your beer is to use a HERMS coil in place of infusions or direct heating to adjust or maintain your mash temperatures. The heat is indirectly transferred and is both efficient and gentle for your brews.

Not all IBC totes are made equally.  Some plastic intermediate bulk containers are made as cheaply as possible to store and transport waste oils or hazardous materials.  These plastic IBC totes, however, can allow oxygen to pass through the plastic, which can oxidize wine, cider, beer and other beverages or liquids.  If maintaining flavor and limiting oxidation is important to you, we recommend using a stainless steel ibc container.

Stout Tanks and Kettles’ IBC totes are designed for craft beverage production, cannabis and pharmaceutical uses. If quality is a concern for your product, here are some things you should consider when searching for intermediate bulk containers:


IBC totes are designed to fill the gap between drums/barrels on the small side, and permanent tanks on the large size. They fill that intermediate need for storing and transporting liquids.

Forklift Accessibility:

All IBC tote tanks should be easily moved with a forklift, and easily stacked when full or empty.  While some IBCs can be forklifted only from one direction, it is better to have a tote that is accessible from any side.  This will help to increase maneuverability and save you time when loading and unloading your product.


Please make sure that your IBC can withstand the weight of another full tote on top.  All of Stout Tanks’ IBC totes are forkliftable from 4 sides and can be stacked 2 high when full. This is a great way to save storage space in your building.


Materials matter when it comes to IBC construction. Plastic IBC totes are popular because they are less expensive than stainless steel, but not all plastic is rated for food and beverage use. Some plastics will pick up flavors and odors from the previous liquid in the container, and this can affect the flavor and aroma of whatever is in the tote next. Food-grade plastic IBC totes are not always sanitary. Plastic is easily scratched, and any scratch in plastic can harbor bacteria or yeast that can infect your container. Once a plastic IBC is scratched, it can be difficult or impossible to clean completely. Many plastic IBCs include NPT fittings or NPT-to-tri-clamp adapters, which are less expensive but require manual cleaning and still allow bacteria to build up over time. All of our tanks feature stainless steel tri clamp fittings and to ensure the most secure and sanitary connection.

Distilleries or extraction companies that use ethanol, (or any other flammable liquid, including alcohol in greater than 16% ABV) are not allowed by code to use plastic IBCs for storage. Many building codes specifically prohibit plastic containers for any flammable liquid. But even the type of stainless makes a difference. Many distilleries find that neutral grain spirits (also known as GNS or NGS) are hard on 304 stainless steel, and prefer to store their ethanol or GNS in 316 stainless. Stout Tanks and Kettles sells both 304 and 316 grades of stainless steel IBC totes.

Temperature control:

If you need to control the temperature of the contents of your IBCs, stainless steel gives you a couple of options. First, stainless steel is an excellent conductor of heat energy. Many winemakers and brewers choose single walled (non-jacketed) IBC totes that can be stored in a cooler, cold room, or barrel room. The difference between the ambient room temperature and the contents of the IBC tote are equalized via the thermally conductive stainless steel.  Plastic totes insulate the contents of the tank more-so than stainless.

Stout Tanks offers stainless steel totes with glycol jackets for more precise temperature control. Jacketed totes have an extra external jacket layer for chilled or heated glycol to circulate. You can mount a temperature probe into your IBC and circulate glycol to maintain the precise temperature for your tote. If you need accurate temperature control, faster temperature changes, or if the space in your cold room is limited, you should consider jacketed totes.

Maintenance Cost:

Price is obviously an important factor in any IBC purchase, but the costs to maintain, clean, and replace an IBC are also important considerations. Stainless steel is durable, and will last decades when maintained properly. Plastic IBC totes will last only as long as the plastic is not scratched, stained, or contaminated with flavors or odors. Stout Tanks’ totes are cylindrical which makes cleaning much easier, eliminating tricky corners in rectangular tanks. Plastic IBC containers often have many nooks and crannies.  Stout Tanks and Kettles’ IBC totes come with a sanitary tri-clamp port for Clean In Place (CIP) spray balls. A tote that takes extra effort to scrub and verify cleanliness will be much more expensive in the long run than a tote you can CIP in a jiffy.

Uses and Applications:

Many brewers use IBC totes as a cost effective cold liquor tank. A non-jacketed tote in the cool room or a jacketed tote connected to the glycol system will provide a nice reservoir of cold water to cool your wort. Many winemakers use a tote as a barrel topping tank. They fill a tote with wine and move it around the barrel room wherever needed.  Distillers and cannabis extraction companies use IBCs to store their distillate or ethanol, or to infuse alcohol with botanicals. Kombucha brewers use IBC containers to steep and store tea, or to infuse tea with botanicals or other back sweeteners. The uses for IBC totes are limited only by your imagination.

Take a look at our Jacketed and Non Jacketed IBC totes