I think one of the most important aspects of beer brewing is maintaining the temperature at a suitable level. Yes, there are other important aspects of beer brewing like proper sanitization and so on, but it is surprisingly that a lot of brewers don’t know that maintaining a more or less constant temperature is very crucial to creating a good tasting beer. I have been reading beer brewing forums for months now and I am shocked to read brewers giving other brewers advise like “lower the temperature fast!” and so on. Although keeping a low enough temperature for your yeast strain is important, what is also important is to ensure the temperature is lowered gradually. Do not “shock” the yeast with sudden increase or decrease in temperature as they will stress the yeast and it will produce off-flavours. My recommendation is to ensure your wort is at the correct temperature first before pitching the yeast. This way, you won’t subject the yeast to fluctuations in temperature since you need to either increase or decrease the temperature. Your only chore now is the maintain that temperature.

But truly, maintaining a constant temperature is not as easy as it looks. The ambient temperature in the morning and at night can vary quite a lot. And of course, the place where you place your fermentator is also important. I am guessing the best place to keep your fermentator is in an air-conditioned room. However, this is not always practical and to keep a temperature of 20°C in Singapore can be expensive. Well, there is always the storeroom or any place where there is no direct sunlight like your study but those usually range about 25-28°C. In Singapore, you just won’t get the optimal temperature for home brewing if you don’t have air-condition or some other resource.

One of the coolest thing to use to maintain a constant temperature for your fermentator is to just use a big plastic tub with cool water and add your fermentator into it. Then use a shirt or a towel to act as a wick to draw water over the fermentator. For best effect, blow a fan at the fermentator. Due to the evaporation that occured, the temperature of the fermentator will be go down. In the daytime where the temperature should be warmed, the evaporation will cool down the fermentator. At night, the decrease in temperature will be offset by the less warmer water and you will get a more or less constant temperature.

Or you could use something which I have been using since day 1. It’s a coolerbox. Basically what you need is something to insulate the interior temperature from the ambient outside. So either those camping ice box or a styrofoam box big enought to fit your fermentator will work. You can use water (like the above example) or just use ice like what I am using now. You either add ice packs or remove them to get the correct tempertaure. I have to admit, it can be a bit troublesome to change ice packs but in all seriousness it takes all but 5 minutes of your time. I normally change twice per day. If you are interested, please read the review I have done on the cooling box from iBrew. I managed to get a constant temperature of 15°C with the cooling box for one or two weeks. Pretty useful item for doing home brewing in Singapore.