Temperature Control Owns My Soul

One of the things that deterred me from starting brewing as soon as I received the kit was the lack of "adequate" temperature control. I can't exactly put Higgins in a box, and expect him to mind the fermentation while I'm gone.

I'm an engineer by training and character. As much as I appreciate the art of brewing, and hope to appreciate it more by participating, I am comforted by the science. There are knobs to turn, and variables to control that can influence product quality. Brewing isn't a hocus pocus black box, like vinting. Who cares about the slope of the hill where my ingredients grew? In fact, I’d wager that there wasn't a hill within 500 miles of where my grains grew. That's how little hill slope matters to brewing. Now I might care about whether my hops grew in Europe or in America... but that's mostly because American hops are on steroids. It's widely acknowledged, and can be traced to the concentration of certain acids. If I wanted to get industrial, I could control flavors by controlling the concentration of that acid in my brew. Of course, I'm just starting. That knob is out of my reach.

The only knob I can really get a handle on is fermentation temperature. Ale yeasts generally like fermenting somewhere between 60 and 70 degrees. Different strains have different comfort zones, but the ballpark is the same. If the temperature is too cold, the yeasts get lazy and don't do their job. If it gets too warm, they go crazy and start producing by-products like esters which aren't always well received by the beer drinker. Some times they're desirable, and can give a fruity taste. Sometimes they are just nasty.

Generally, I like yeast flavors and subtle esters in my beers. I'd like to ferment warmer temperatures (68-70) to ensure that I get some esterfication, but not too much. My fermentation closet (I live in an apartment) is about 65 degrees. It's ok, but not perfect. I want that temperature control.

My first solution was the purchase of a fermiwrap heater. It's a flexible piece of plastic with a lithographically applied coating, conveniently hooked up to an electrical plug. It's a good idea. The funny thing was that the fermiwrap was made in CA, but the heating element was manufactured by a company here in MA, Calorique. It must be a nice weekend job to take two commonly available parts, clip them together, bag, and distribute. Maybe I'll figure out a must have homebrewing gadget, and actually make money at the hobby.

Anyway, Kimble decided he didn't like the fermiwrap, and clawed four holes in it as I unrolled it for the first time. He didn't short anything, so I just covered the holes with electrical tape and plugged it in. The fermiwrap worked fine and warmed my brew up above 70 degrees. Unfortunately, the fermiwrap has no thermostat. So I had to plug and unplug it. I suppose I could have devised some goofy timer control. At this point, I am unwilling to drop $80-100 on a direct temperature controller to get the fermiwrap to behave.

My solution, which should have been my first idea anyway, was to go out and find the cheapest space heater with some sort of variable control. I found a ceramic one, with an oversized PC fan, and a dial that looks to offer more than 3 or 5 control set points. It works fine for heating, but doesn't seem ideal at dealing with cooling wart. The Fermiwrap had heated Clark's Kent’s Manners up to 74 degrees by the time I came back from the store. I swapped the space heatre in, and at its lowest sitting, the heater would activate before the wort had cooled.

I pulled the heater from the closet and let the wort drop below 70, now the heater is back and seems to be holding temps around 71. I don't know exactly because I'm using a Fermometer (a sticker that changes color along the scale and has 2 degree increments). It's not precise, but seems accurate and is incredibly cool. I've slapped them on all of my carboys, and put one in my beer fridge.

For a guy who's so anal about control, I seem to have a relaxed attitude about 1-2 degrees here or there. They call it a dead band in the world of process control. Instrumentation error, systems lags and the like add up to a nice window of "I can't tell the difference and I don't care".

Of course the upper end of this strain's recomended range is 72, but I doubt I'd be concerned if the limit was 70.