It is commonly said that brewing beer is about working with sugars, however, beer is made by working with grain starch. The starch cannot ferment, so our job as brewmasters starts by converting the starch into sugar so we can add our yeast and make our precious liquid we refer to as beer.
The Mash is the place where we transform these starches into sugars either with a single-temperature infusion, multi-rest mashing, decoction mashing or a combination of these. Since we are working with crushed grains here, we must make a decision as to how fine we want to mill these bad boys to get the sugar out. The finer grains will be converted faster and better, but it becomes mission impossible to separate the wort from the grains, a process known as lautering.
The wort is simply the mixture of water and the sugars from the grains. Some refer to the wort as unfermented beer. They are both the same.
After we get our wort out of the lauter tun we are ready to boil and create our masterpiece. All we have at this point is sugar and we need bittering hops as well as finishing hops to give our beer the flavor and aroma we like.
The bittering hops are added early in the boil and the finishing hops are added late in the boil. There are other techniques for hopping your beer such as First Wort Hopping (FWH), Dry Hopping, Krausen Hopping, etc.
Once our final wort mixture is complete, we must cool it down asap to yeast pitching temperature to avoid any bacteria from forming. Cooling can be done by placing your pot into an ice filled sink or tub, adding ice directly to the wort or using a wort chiller.
When the wort cools down enough to pitch the yeast, then the next obvious step would be to pitch the yeast. The yeast’s role in this whole shebang is to eat up the sugars and convert them into CO2 or Carbon Dioxide and Alcohol. This is done during the fermentation period which is done in a controlled environment with a steady temperature. The wort turning into beer needs to be in a airtight container with an airlock to allow the CO2 to exit and not let any air back in.
This is the time when you see Krausen form on top of your beer, which just looks like foam and it’s an indication that the yeast is reproducing and doing it’s job. By eating up the sugar, the yeast is bringing down the density or gravity of the beer.
You know fermentation is done when your hydrometer reads a final gravity around 1.014 give or take .007 depending on your recipe.
You can do a one stage fermentation process or use a secondary fermenter to condition your beer. Then the next step is bottling the beer or kegging the beer. If bottling you’ll need to prime the beer with sugar to get the carbonation going.
This is more or less beer brewing in a nutshell. Now, you probably don’t have a malt mill, a mash tun, lauter tun, or wort chiller at home, but you can still brew using simple home brewing equipment.