Examination of fermentation temperature control methods

I mentioned in a previous post that I remodeled my kitchen. Although that was a huge expense, one that most likely will never be eclipsed in this house,  two important things happened: 1. My wife got a kitchen that was worthy of her, and 2. I got nearly $1500 in rebates and cash back. Couple that with a $150 gift certificate from the aforementioned wife, and I bought what I’ve been meaning to get: a jacketed conical.

There are numerous ways to maintain temperature during fermentation:

  • Don’t. This is the easiest one. Most of us start out here.
  • Brew with the seasons. This is similar to Don’t. However this one is most like traditional brewing, where one makes recipes that coincide with the climate. There really is nothing like making a saison in the summer,  leaving the fermentor in the garage and see what happens.
  • Evaporative cooling. Stick the fermentor in a bucket or tray, drap a piece of cloth over it and fill the tray with water. I think of this as the “swamp cooler” method. Blow a fan on it to increase the cooling capacity.
  • Climate control. Probably the most used method by homebrewers. This involves controlling the temperature of the space the fermentor is occupying. Common methods are in an unheated closet, garages in spring and fall, and spare refrigerators and freezers. Using the last two options typically requires a temperature controller of some type,  such as an Inkbird. Energy efficiency can really suffer here depending on the situation. One of the most ingenious methods I’ve heard of is putting a fermenter in a small enclosed space and using an incandescent bulb to heat it.
  • Direct heating and cooling. This is where a jacketed vessel fits in, however there are many applications of direct heating and cooling.
    • Immersion: coils, tubes or elements directly in contact with the wort. These can be electrical, such as Peltier-style devices, or fluidic.
    • Insulation: using the exothermic properties of a warming fermentation by utilizing jackets or wraps to prevent cooling.
    • Heating/cooling wraps: using powered devices to directly heat or cool the outside of a vessel. They can be electrical or fluidic. Common devices such as Fermwrap, heating pads, heating tape are for warming, and cooling is becoming more popular as well by pumping water or glycol through thin, wide tubes wrapped around the outside.
    • Jacketed vessels: these are double walled vessels that allow fluid to be pumped through to control temperatures.

There are many methods of fermentation temperature control, and I’ve used several of the above methods, but I’ve more recently decided to go the direct route in an effort for precise control and efficency. Make no mistake; great beer can and is made using any of the above methods. In fact award winning beer can be made in a yard sale carboy in the garage. Great beer can be made cheap, but what costs is control which enables repeatability. How do most commercial breweries make the same great beers batch after batch? Control.

I usually make my lagers between January and March. However lagers are usually fermented for two to four weeks at temperatures below 55° F (~12° C). What four week stretch will keep that temperature steady in any year? This means that without precise control,  especially in the crucial early stages of yeast growth, the character of a recipe will never be the same twice. I have a Wee Heavy recipe that is fantastic and everyone who drinks it loves it, but I’ve never been able to recapture the magic of the original batch, much to my wife’s chagrin. My last batch was so hot, due to higher alcohols generated during fermentation, that it was close to undrinkable.

I originally planned on getting a conical with a coil for cooling and a fermwrap-like device. After some research online and at breweries, I settled on a unitank design as they were becoming more popular and affordable, and could cut down both oxygen ingress during racking and time from grain to glass. I dropped Stout (my first favorite choice for being all TC equipped) because they didn’t carry a unitank in the thr size I wanted, and Blichmann didn’t have anything that fit my requirements. That left Ss Brewtech and Spike as the two brands that had the features that I wanted. Spike had a 10 gallon that was the perfect size, but didn’t have all the features the Ss unitank did, but was bit cheaper.

After hours of compiling features and comparisons, I ended up throwing all that effort out the window when I found the Brewer’s Hardware jacketed conical. The downside? It was very expensive. The base 8 gallon jacketed configuration set me back $1250, the cost of a fully outfitted 14 gallon Ss unitank. With a blowoff tube and casters, I was looking at just under $1500. Add on the vacuum arrestor and pressure gauge, and delivery charge (it needs a lift gate), and this was over $1700. I also lost out on a front mounted temp gauge and sampling coil (15 gallon and up has those).

In the next installment I’ll go over the unboxing and look at components closer. But why did I not go with a less expensive unitank with a coil? For one, cleaning. This may be overblown, but I’ve read constant complaints about cleaning coils. The more important reason? Contact area. The surface area of coils are very limited compared to the entire surface of a conical. This is especially important for cold crashing, as cold are known to freeze the beer contacting them and cause an insulation affect.

In the end, temperature control is always good, no matter how it is attained. Coils and elements are great choices and will most likely help create excellent repetable beers. I am very much looking forward to taking this thing for a spin, however.

Very top heavy.


  1. You’re gonna love it. I have a BH jacketed conical also, and am so glad I went this route instead of the more common choices you mentioned.
    Rig up a chiller and never look back!

    Liked by 1 person

    1. Thanks. I’m excited that it’ll give me some better control over fermentation, especially in regards to trying out some interval lager schedules.


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