There’s a lot of magic that has to happen for beer to become beer. Some people refer to this magic as “science” but that word is scary and the word “magic” is fun. While it’s true that beer has been around for centuries and the techniques behind making it have not changed much in that time, the technology and knowledge of why those techniques are used are much better understood.
As we’ve covered before, the simplest way to describe making beer is that you need to create a liquid with sugars in it, then add yeast and wait. Boom. Beer. This week, we’re going to look at how you get that sugary liquid using only the grains that you chose to use in your grain bill. This is done through something called a “mash” and there are three main types that we’ll take a brief look at. I wanted to quickly point out that when you mash the grains, the grains first have to be run through a grain mill to break open their husks and expose the starches they contain which you’ll learn more about below.
Per the usual, my typical disclaimer about the fact that this is a general overview of the topic mentioned above and not an in-depth science lesson applies.
What’re we doin’ exactly?
Before I go over the three types of mashes, let’s lay out what we’re trying to accomplish. We need to convert the starches in the grains into the sugars that we need. This is done by adding hot water to your grains at a water to grain ratio of 1.5:1 quart per pound. Now that you know how much water you’ll need, there are very specific temperatures we need to hit in order to make the science work behind this work. The sweet spot (pun intended) for this to happen is between 148-158 degrees Fahrenheit. In order to fully convert these starches, you’ll also want to keep the mash at this temperature for about an hour. While commercial breweries have some fancy things to help maintain this temperature but most home brewers use a cooler (like you’d use to keep your beer cold at a BBQ) because it seals nicely and it’s insulated. Now, let’s dive in…
Mash Type #1: Single Temperature Infusion (Single Step)
This is the most commonly used method of mashing by home brewers and commercial brewers alike. The idea is to heat up some water hotter than the temperature you want to mash at. This is called your “strike water” and the reason behind this is quite logical if you think about it. The grains you’re using aren’t inherently hot so when you add water to them, they’re naturally going to make that water’s temperature drop. So when you add your strike water to your grains, it’ll typically be about 10-15 degrees warmer than your mash temperature. For example, I brew a Schwarzbier that I want to mash at 152 degrees so when I begin, I add 162 degree water to the grains. After an hour, take the beer out of your cooler and the sugar will have been extracted.
Mash Type #2: Multi-Rest (Multi-Step)
If your powers of deduction are strong (and I really hope they are) you’ll be able to to make an educated guess on what is done for a Multi-Step mash. While not as common as the Single Infusion, you’ll find home brewers and commercial brewers alike that swear by it. As discussed by John Palmer in How to Brew, the most common multi-rest mash temperatures are 104 – 140 – 158 and each of those are held for about a half hour. If those sound like weird numbers it’s because they work out to be 40, 60 and 70 degrees Celsius. You see, before malts were made as well as they are today, you really needed to put in some extra work to make sure that these starches were being converted. This was done by giving the sciencey part of the process time to do its thing at those targeted temperatures. There are big words that I could throw at you but the gist of it is that by giving these different “rests” at these temperatures, you’re hitting the sweet spot for these conversions to happen in the best possible way. To get to these temperatures, you’ll need to obviously add water or apply heat during the mashing process. You can add enough hot water to get to each temperature if you’re mashing in a cooler (knowing that taking the lid off to add to it each time takes away some of the heat as well) or if you mash on a brewing system with a heat source, you can simply turn the heat up on that and let it rise. Starting to see why mash most folks prefer the single infusion, yet?
Mash Type #3: Decoction Mash
This is by far the least common mashing method and I’d be willing to bet there are only a handful of commercial breweries in the states that would go through the trouble of using it on a regular basis. This method is very similar to the multi-step mash that we just looked at but it requires the actual boiling of the grains themselves. Wait….what? Yes, this goes back to the days of those poorly modified malts like we mentioned above and also the days where the thermometer wasn’t around yet. Getting to an accurate temperature wasn’t always so easy to do. Brewers figured out that if they removed some of the grains from the mash, boiled them, then returned them to the mash, that it would raise the temperature of the overall mash and get them to their next “rest” period. It’s the same idea as a multi-step mash except you’re adding boiled grains, not just hot water to reach your next rest temperature. Most brewers that employ this method are either German brewers making german beers or perhaps American brewers wanting to brew a traditional German lager. Either way, it’s complicated and messy so if you ever choose to go down this road, good luck.
If you visit a brewery or talk to a buddy who brews at home, you’re going to most likely see the single infusion mash being used. That’s not to say that the other ways don’t have merit, however those ways came about as a necessity due to the poor quality of the malts that brewers had to use. Nowadays, multi-step and decoction mashes are definitely not necessary but do give you a bigger sense of control over the final product and if done right, can allow you manipulate the mouthfeel and body of a beer in a bigger way. At the end of the day, as long as the beer tastes good, the brewer can spend as much or as little time on the mash as they feel inclined to do.
Do you have a beer term that you’d like to know more about? Email me at email@example.com or comment below with something you’d like to see explained in a future Vocabrewlary Lesson.