If you are a new brewer, chances are you started out brewing using malt extracts rather than creating your own wort from malt and/or other adjunct ingredients. Malt extracts, dry or liquid, are commercially created from a mashing process done for you and then processed to create the concentrated extract you add to brewing water to go into your boil.
All-grain brewing, on the other hand, requires you to use the various grains (barley, wheat, etc.) “from scratch” and perform a mash in order to collect the wort you will boil in the next step of the brewing process. In return, you are rewarded with a level of control over your recipe and your finished beer you simply cannot get from extracts alone. So what exactly is a “mash” and how does it affect your beer?
Mashing simply refers to the process of steeping crushed grains in hot water, typically for about an hour, which allows some interesting chemistry to work: enzymes naturally present in the malted grains are activated and they in turn start breaking down the complex carb sugars in the grain. This creates simpler sugar structures that beer yeast can later ferment, creating alcohol, CO2 and flavor compounds. At the end of the steeping time, you rinse the grain bed with hot water in a way that allows you to hold back the grains and collect just the sweet water (called “wort”) that you will use in the boil.
There are two major advantages you have as an all-grain brewer performing your own mash. First, you get to pick your ingredients. When you buy malt extract, you have no control over what grains the supplier chose to use, and you don’t know their quality or source. Sort of like going to the supermarket to buy a can of soup and heating it at home to eat as opposed to shopping at a farmer’s market to pick your ingredients for your vegetable soup.
The second advantage to performing your own mash is even more important: the temperature at which you steep the grains in the mash greatly affects how the finished beer comes out. Let’s say, for example, you are mashing grains to make a pale ale. Let’s say you use the exact same amount and type of grains to make two different batches of that beer. You mash the first batch at 148°F and the second batch at 154°F. The two beers are likely to come out quite different. The batch mashed at the lower temperature will likely have a thinner “body” to it, and will likely be higher in alcohol content. The batch mashed at the higher temperature will probably come out with a fuller mouthfeel, retain a bit more of the malt character, and have somewhat less alcohol. The point is, you are in better control of what your beer will come out like if you do your own mash. When you brew with commercially available malt extracts you don’t really know what to expect and you can’t control the outcome anyway.
Looking for easier ways to start experimenting with all-grain mashing and brewing? Check out our upcoming post on “Brew In A Bag”, or “BIAB” for short.