Fermentation ideas.

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Apr 4, 2011
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So, my cousin and I built a couple of fermentation chambers using chest freezers and temp controllers. I’m looking for ideas for heating the chest freezers for winter time. I live in Michigan where the temp can stay cold. The chest freezers will be in the garage where will be consistently below freezing. During the winter months, I’m thinking of doing a few different lagers over the winter time as our home brew set up is at his cottage where it will be winterized, so we won’t be brewing for a few months, while the house is unoccupied. The electricity will obviously still be on, but water will be shut off. Looking for ideas from you wonderful people. TYIA
Search the threads for ferm chamber heaters.
Some use ceramic heat lamps used in reptile terrariums.
Some use small watt (25-40) light bulbs, inside a light proofing stovepipe so you don't light-skunk the hop oils.
Some use the product FermWrap, or similar, which attaches around the fermenter.
Some use small personal (eg Lasko) heaters. All plugged into Inkbird or STC controllers.

In choosing a heat source you don't want to go big as the overshoot with a temp controller will be large. That is, the controller will turn on the heater when needed, and by the time the set point is reached, too much heat will have been put into the interior too fast and the temp will overshoot quite a bit. In wintertime, however, you likely only need to plug in the heat side of a temp controller, just as in summer you likely only need to plug in the cold side.
I use a reptile heater mat with a rheostat(just in case) wrapped with a double layer of reflectex,plugged into a st1000. I have it on the top shelf of a side by side where the freezer (lagerator) side is set to 33* and the fermentation side stays around 50*. I ferment at whatever temp I want.
I just taped a ferm wrap to the back inside panel of the fridge , controlled by a STC. The fridge is in my garage in Colorado and works in winter.
im going to say that your cheap basic heating wrap from the pharmacy is your simplest solution and best bang for your buck. just make sure you get the ones that do NOT have auto-shutoff. wrap them around fermenter with bungie cord and you're all set.

they're relatively cheap. (have found a couple at thrift shop/garage sale)
they're typically adjustable to low/med/high to help dial in and prevent overshooting
they provide a bit of insulation against the cold air, helping to stabilize temps which doesnt happen with smaller types of wraps, IR light bulbs, or air heaters
I'm in Chicago and I brew all winter long in an unheated attached garage without a heated ferm chamber.

Instead the fermenter is wrapped with one or two 13W seedling mats (depending on weather severity) and insulated with a double layer of Reflectix. It's all held together with a draw strap to ensure good contact, and sits on a sheet of foam to insulate the bottom. The fermentation temp is managed by an Inkbird controller with the temp probe either down in the beer using a thermowell or tucked between the fermenter and insulating wrap somewhere away from the heaters. I've tested it with some additional insulation around the neck/shoulders of the vessel but the seedling mats have enough power to maintain proper temps without it.

Benefits of this system are that its cheap and easily scalable; I've successfully huddled two fermenters together in a pinch, a heater on each and managed by a single Inkbird controller. Also it's quick and easy to set up, maybe 20 minutes tops, plus ten minutes sipping a homebrew and admiring my handiwork with a strap clamp.

Another huge benefit is the space it saves in the warmer months when I have no need at all for a ferm chamber; I tend to brew seasonally so I'm not attempting 52f lager ferments in July, so the equipment for managing three fermenters all winter easily tucks into a 5 gallon bucket for storage in the warmer months.

Which brings me to a great piece of advice: practice the rhythm method and BREW SEASONALLY!
I got an oil pan heater and glued it to a standoff on the wall of the inside of my chest freezer. Beneath it is a muffin fan connected to a right angle duct that blows air across the heater. The fan runs 24/7 but the heater is connected to an inkbird controller on the heating side and the freezer itself is plugged in to the cooling side. I can maintain plus or minus 2° F anywhere from freezing to over 100° F regardless of the ambient temperature.
I’m heating a full size side-by-side fridge so I needed to go with a 150w reptile bulb in a porcelain light fixture with an old computer fan mounted to it to spread the heat. Cheap and works well.
I use a 3watt seed mat from Amazon. I place it up against the wall several inches away from the fermenter(s). Works great but my garage doesn’t get much below 40 or 50 most of the winter. Live in NC and the garage was insulated

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