OnTap Magazine

If a cooler fermentation is what you’re after, especially in the balmy climes of sunny South Africa, then you can always take a cue from that song by that guy. Ice, ice, maybe? Using ice to chill out your fermentation is perhaps the cheapest, simplest solution. Bonus: it requires roughly 0% DIY skills. The principle is simple: if you immerse your fermenter (bucket or carboy) in icy water, it will, in turn, cool down the fermenting beer. HERE’S HOW TO GO ABOUT IT Buy a large container, like a plastic bucket, that can hold your fermentation vessel. Ensure that it is deep enough to immerse the vessel almost entirely. With the fermenter inside, fill the container with good old H2O until it reaches the same or slightly higher level than the wort inside. Now simply cool down the water with ice. Experiment. You will have to play around a bit with the number of ice blocks used versus the temperature you achieve over time. Remember to measure the wort’s temperature as well as the water’s. Stay sterile, make notes, start a spreadsheet, and embrace your inner mad scientist. Whatever you do, it’s likely that you will have to replenish your ice blocks periodically to maintain the correct fermentation temperature. This can vary depending on the ambient temperature of wherever in your house you’ve positioned the fermenter. It’s a good idea to measure this room’s temperature, which will allow you to construct a cool ambient vs. water vs. wort temperature spreadsheet that will make stats nerds just a little bit giddy and out-of-breath. Also note that unchilled wort’s temperature will always be warmer than ambient because fermentation is an exothermic reaction. Some folks also use a towel, wrapped around the fermenter and placed in the container to act as a wick for the cooled water. In my experience it doesn’t do much more than create a health hazard as the towel slowly turns into a scary, mouldy mess. Avoid. You might be wondering about how to control high temperature fermentations or maintain room temperature when it’s seriously cold outside. Well, in South Africa, we’re blessed with remarkably temperate conditions, so usually, keeping things warm isn’t much of a problem. Even so, there might be times when your fermentation is too cold to do you any good. What to do? There are two routes. One: simply brew cold-temperature beers like lager or Kölsch. But what if you absolutely have to brew that special Belgian and it needs to be fermented at 29°C for two weeks? Well, then you can employ one of two methods: low tech or high tech. Low tech has you wrapping your fermenter in a blankie (regular or space variety) and placing it in a warm zone in the house. High tech requires an electric blanket and a high tolerance for high electricity bills. Your choice, but do consider the cost (both in money and extravagant energy usage) vs. reward of this method. And Kölsches (Kölschen?) are really nice. Just saying. THE VANILLA ICE METHOD Cost. This method is as cheap as they get. Apart from the big container and (possibly) blue ice block thingies, there’s virtually no outlay required. CONS PROS Effort. Replenishing ice blocks and measuring everything all the time to ensure consistent temperatures can be a bit of a pain. If your house or town also experiences massive ambient temperature fluctuations, the ice method can become a massive pain in the you-know-where. RUNNING HOT KEEPING A CONSTANT FERMENTATION TEMPERATURE O P T I O N 01 1 2 Simplicity. Using ice is (relatively) simple. Once you have your temperature relationships dialed in, there’s not much else required from you. Style limitations. While maintaining ale fermentation temperatures using the ice method is relatively simple, doing the same thing with lagers can be difficult. In my experience, especially in summer, you just can’t ever get the water temperature low enough for proper lagering. Sterilisation and oxidation. Because you’ve got to measure your wort temperature periodically, you run the risk of contaminating your brew either with nasties or with oxygen. Another bummer. Consistency. Unless you are super-dedicated and accurate in your measurements, it might still be challenging to maintain consistent temperature as the ice melts, the water evaporates, and general chaos ensues. 1 2 4 3 62 | Spring 2018 | ontapmag.co.za