Maintaining low fermentation temperatures without a fridge
Controlling temperature during fermentation is very important for best flavor and batch-to-batch consistency. Sometimes, small breweries will control fermentation temperatures by regulating the room temperature or placing their fermenter in an old fridge that can be turned on and off. While these methods work, they have several drawbacks including:
- energy inefficient (heating or cooling an entire room)
- imprecise (temperatures in the fermenter can climb several degrees above the room temperature during active fermentation as air is not a great conductor of heat)
- bulky (a large fridge gets in the way)
- awkward (moving fermentation vessels in and out of coolers can be difficult)
BREWHA's jacketed fermetners (3-in-1 and 4-in-1) provides a simple solution. By passing a warming or cooling/chilling liquid through the jacket, the temperature in the fermenter can be maintained at a precise point, providing perfect conditions for yeast, ensuring highest beer quality.
In many locations the fermenter temperature can be maintained by just passing municipal water through the jacket. As the ETC senses the fermenter warming up, it sends a signal to open the Temperature Control Valve (TCV), letting cooling water into the jacket. When the temperature drops back to the set point on the ETC, it closes the TCV and stops the cooling water.
In some areas, however, the municipal water is too warm to properly chill the fermenter or will consume too much water. In this situation there are two options:
- a glycol chiller (often expensive and cleanup can be messy)
- BREWHA's Water, Beer and Wort Chiller. These chillers are more powerful than the chillers mentioned above but should still be used in conjunction with municipal or well water to bring the wort temperature down from boiling. The municipal/well water is used to do the lion share of the work (e.g. bring temperature from 212F to ~80F) and then switch to the Lindr chiller for the remainder. Municipal water is very efficient when the temperature difference between wort and chilling water is high, but not efficient when the difference is small. For example, approximately 30% of municipal water is used to bring temperature down 70% of the way, and 70% of water is used to bring temperature down the last 30%. So the least amount of water can be used by employing a chiller to do the last bit of work. A few extra benefits of this chiller are that it has it's own pump, and it has stainless beer chilling lines built right in for chilling beer from the keg to the tap. This chiller has a 38L (~10 gallon) reservoir, however, if a larger reservoir of cold water (cold liquor tank) is needed, a secondary vessel can be used to store cold water (by using the Chiller to cool it down ahead of time) so it is ready for use on brew day. It can also be used to maintain temperature during fermentation. By connecting the Chiller water pump to the inlet of the fermenter jacket, and the exit of the jacket back to the Chiller reservoir, and by using the ETC to turn the Chiller pump on and off cooling water can be pumped into the jacket whenever needed. As always, to minimize temperature creep away from the chilling set point, it is best to keep the chillant temperature (cold water in this situation) relatively close to the temperature of the fermenting wort. If there is a high temperature difference (ie. the chillant is really cold), when the pump shuts off, the remaining cold water in the jacket will continue to chill the wort for a little while, dropping the temperature further than intended (and creating a vacuum inside as the beer and air contract). It is also good to fully submerge the return water hose (coming back from the fermenter), or place the top of Chiller at the same height as the exit port on the fermenter, to prevent air from getting into the jacket and the water inside the jacket from draining out the bottom and back into the water reservoir each time the pump shuts off (which can cause the reservoir to overflow).
An added benefit of the Lindr Chiller over a glycol chiller is that it is designed to operate with regular water, so it is easy to switch back and forth from using the jacket for sparge water during mash (see this blog for details), to municipal water after the boil, to closed-loop feed with the Chiller. If using glycol for one of those steps, the jacket would need to be thoroughly cleaned each time and would be messy.
Click here for more reading on temperature regulation.