So...finally have these things going...hopefully I'm using them correctly
Homebrew 101: Keep your cool bro….
August 20, 2014
This week’s homebrew post is a recommendation from Jeremy Altheide (Hooray! Your name is now on the interwebs……forever) The previous Homebrew 101 post on yeast is a good spring board for what will be covered here, so if you haven’t already read that post I’d recommend clicking on the picture of them purdy germs on the homepage and catching up. Now that we have that out of the way, it’s time to talk about keeping your cool, specifically when it comes to wort and primary fermentation. This step is often overlooked or under-addressed by home brewers, resulting in beers that fail to live up to their potential.
What’s the big deal?
Allot of people who are just starting out with home brewing or who are more casual in their brewing habits don’t understand why temperature control is so crucial throughout the entire brewing process. Have you ever had a beer that tastes like bananas or bleach? There is a good chance this is the result of temp’s being incorrect at some point for that brew. This can affect more than just the taste of a beer, everything from clarity to alcohol content can also be impacted and result in a brewing project having a significantly different outcome than was intended.
This part of the temperature game is particularly crucial as it establishes the environment for your yeast in the wort. If wort is too warm when yeast is pitched, this can result in higher levels of something called diacetyl (random fact: diacetyl is what is used to make the fake butter in microwave popcorn). While diacetyl is always going to be part of primary fermentation, at low levels it is reabsorbed by yeast in secondary. Using a copper wort chiller or a chilling plate and pump to quickly reduce the temperature of your wort after a boil ensures that your yeast will be will be happy in their new home and you won’t have any nasty byproducts from this stage.
Temperature Control during Fermentation
Once you have your wort chilled and your yeast pitched, it’s important to make sure your fermentation vessel remains at a consistent and appropriate temperature for what you are trying to brew. It’s important to know what the appropriate temp is for the type of beer you’re making for a few reasons: If it’s too cold your yeast will become dormant and the wort will under-ferment. If the temp is too high you will get heavy alcohols called fusels from fermentation, which later become esters and poof, you now have super nasty banana tasting beer.
It’s fairly easy to convert an old chest freezer or refrigerator to be your temp-controlled environment and most brewing supply stores have all of the necessary electronics to make that happen. Going with a fridge or freezer also makes it easier to cold crash during secondary; the process by which yeast and other particulates are forced to settle at the bottom of the secondary vessel. If you want a lower tech way to regulate temperature, John Palmer provides a good option in his How to Brew book (notice how often I reference this book by the way….just sayin’) by filling an old bathtub or wash tub and submerging your fermentation vessel. The water will keep everything at a relatively consistent temperature and provides a natural temperature control medium when brewing ales in particular.
Keeping things cool after brewing
There is a reason that beer from a kegerator tends to taste better for longer than beer that doesn’t. It’s the same reason you don’t want to drink a beer that’s been sitting in your car all day. For many of the same reason mentioned in the fermentation piece of this post, beer in kegs, bottles, and cans needs to be kept cool enough to stave off esterification (yes that is an actual word) and other issues that can cause a beer to go bad. This part is relatively simple, involving a fridge/kegerator or a low lit cellar temperature area if you are bottle aging a beer. Again, remember that the optimal temperature for keeping a beer will vary depend on the type of beer and container it is in, but the low to mid 40’s range is generally a good base line.
That covers most of the basics on temperatures and why they can make or break your homebrew. Of course, there are much more finite areas of focus within this subject in brewing that can be found in various beer making publications and from your local brew supply store. I hope this helps all of you aspiring to make your own amazing beers at home to be successful in your endeavors. I’m off to have a well refrigerated pint, happy brewing all!