Controlling fermentation temperatures

Question

Controlling fermentation temperatures

SteveMalyj

2017年1月26日 20:08

I'm conscious this is the third question I've asked before I even get started on my first brew, but hey-ho; better to learn from the experience of others and get as close to "right" first time.

I am about to start an ale brew and understand the ideal temperature for fermentation to be effective is in the range of 18 degrees centigrade (c. 64F) to 22 degrees centigrade (c. 72F) - maybe even 20-22C.

My problem is that where I live currently (north west England) the outside air temperature is a crisp 4-8C during the day dropping to freezing at night. The impact of this is that even with regular central heating, the best indoor range of air temperature I can get is between 15C (lowest) and 18.5C (highest) - having taken regular test readings at intermittent intervals throughout a few days - and I am not sure how these factors would impact on the temperature of my brew and fermentation. I don't have a home thermostat in order to keep a constant, so the indoor temperature fluctuates with the timed on/off intervals of my central heating (presently 1.5 hours at 6am, 1 hour at midday and 2 hours from 5-7pm).

I had considered a number of options to maintain a decent temperature including heat mats and brew belts and I am comfortable with the pros and cons of each and their potential effects on the brew. I have ruled out more expensive thermostatic options as too expensive to blow on my first brew.

Does anyone have any thoughts on how they would maintain a suitable temp during fermentation with these conditions? Has or does anyone currently brew ales in these conditions with positive results?

Interestingly, I have read that active fermentation can warm a brew by 5-8C, so assuming I get the fermentation going in the correct range, is it possible that the heat given off during fermentation could actually keep my brew in the correct range anyway?

Topic extract-brewing fermentation-temperature temperature-control ale homebrew

Category Mac

nikitaso · Accepted Answer · 2017年1月26日 20:08

1

nikitaso answered at 2017年1月26日 20:08

water bath and aquarium heater, or buy jacket.

brewchez · Accepted Answer · 2017年1月25日 19:17

You can put your fermentor closer to the heat source in a room. If you have hot air heat you can put the fermenter over a floor vent and cover it with a towel or box. You can also only cover half the vent with a box/towel, placing the fermentor next too (not on) the vent. If you have radiator type heat the same techniques can work but you'll want to have the fermentor further away as radiators tend to get really hot. It takes a little trial and error but its a manageable means of having the fermentor be warmer than the ambient room around it.

Tom L · Accepted Answer · 2017年1月25日 16:21

Remember that yeast are living things and will regulate their own temperature as best they can. I've kept fermenters in rooms with an ambient temp around 18C and the yeast raised the fermenter temp to about 20C. You could also help them by wrapping the fermenter in an insulated blanket.

barking.pete · Accepted Answer · 2017年1月25日 11:37

I live in the south of England where it has recently been even colder than "oop North". At this time of year I go with the seasons and brew the year's supply of lager(!!!). Its perfectly lagered and crisp by summer.

However to answer the particular question - yes, I brew ales, light and dark, during the winter months at "less than room temperature" and they turn out perfectly. Of course beer is a matter of taste and some prefer the fresh (slightly) "fruity" flavour of beer fermented at higher temperatures others prefer a crisp IPA fermented at lower temperatures. But whatever, beer will ferment just fine at 10C or 15C, it just takes a little longer. Think (for example) 14 days instead of 10 days for primary fermentation. As in most brewing, the time is slightly irrelevant. The main factor to judge progress by is the specific gravity (density) of the brew. Maybe it is yeast type dependant - I have heard that "Turbo yeasts" that make up to 21 percent ABV require a rather narrow range of temperatures to achieve their stated attenuation.

If one decides one must ferment at higher temperatures, then I find a heat belt can be better than a heat pad - but both will work. If it is very cold then additionally part wrapping a blanket (or similar) around the fermentation bin will usually do the trick. I have even placed the brew bin next to a radiator, there was definite temperature cycle in the wort from day to night but it did not seem to affect the beer.

Large fast fermentation can heat up and even require cooling in very hot weather. But in UK it is rare to get a "normal" brew to heat appreciably while fermenting. I have possibly noticed a few degrees rise in an insulated brew bin but nothing I thought I should counteract. The "Turbo yeast" instructions state that the fermentation should work well for 25 litre batches but advises against doubling the batch to 50 litres as the "heat produced could adversely affect the fermentation". But that is the only stated case that I know of.

Controlling fermentation temperatures

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