Artisan Spirit: Fall 2021

Page 89

R E C I P E F O R M U L AT I O N Understanding how to read a malt spec sheet is important, but how do you take this information and make it useful in your recipe building? More specifically, we want to know how much grain we need to mash in order to reach a desired wort volume with a target specific gravity. Now, if you’re like the majority of distillers/brewers out there, you don’t bother looking at malt and grain specs. Your recipes are locked in stone, and nothing is ever going to change in that department. But let’s say that you are a single malt producer, and you decide to change barley type. Perhaps you decide to switch from Briess’ 2-Row Brewer’s Malt to a Whiskey Malt. The Whiskey Malt has roughly 3 percent more extract than the Brewer’s Malt, which means your starting gravities will likely go up. This in turn changes your fermentation profile. Another way to look at it is that you won’t need to use the same amount of grain to achieve your desired fermentation profile, a financial bonus that your company’s bottom line will surely appreciate. And this is just one example among dozens of situations that can arise when purchasing grain for a distillery. In short: Pay attention to the malt specs. In order to build a proper mash bill, we need to know a few things. First, we need to know which grain(s) we are going to use. And if we have multiple grain types, we need to know their proportions. A discussion on mash bill design is really outside our scope here. Besides, many people already have some basic numbers in their heads that they think will work. The choice on grain proportion is more often more of an artistic, stylistic, regulatory, and/or marketing-related choice. But even if you have those proportions figured out, you still need to know how much TOTAL grain you need to use. So, what else do we need to know? Well, we should have an idea of what our target gravity is for the wash. Starting sugar concentration will have a significant impact on how our yeast performs and the flavors it produces. For single malt folks, the starting gravity is usually around 1.055-1.065 (13.6 – 15.9 °Brix). American whiskey mashes often click a bit higher at 1.065-1.075 (15.9 – 18.2 °Brix). We also need to know what volume of mash/wort we want to produce. This is usually dictated by fermenter/still size so that one is quick to answer. Ideally, we also want to have an idea of our mash efficiency. Mash efficiency is just a metric describing the percentage of total grain fermentables we are able to extract into our wort with our mash equipment. No mashing system will give you 100 percent efficiency (though facilities with mash filters will often come close). For traditional mash/lauter tun systems found in most single malt facilities, efficiencies range from 85-90 percent (some creep a bit higher than W W W . ARTISANSPIRITMAG . C O M

this). In American whiskey where the fermentation is “ongrain” the efficiency is a bit higher, often around 90-95 percent. The problem is that if you’re just starting out, you won’t know what your mash efficiency is. It takes a few months of production to really get that number dialed in for most people. If you’re unsure, I suggest starting with the conservative side of the above ranges for the type of operation you have. This will get you started and you can continue to tweak things as you get used to production on your system. Finally, we need to know a few parameters from our grain spec sheets. The main informational tidbits that are important to us are the extract values, either coarse or fine grind depending on our milling technique, and possibly the moisture content if the extract value is reported on a dry weight basis. To find the amount of grain for a given mash bill, the equation is: Gravity Points x Recipe Volume = Total lbs of Grain Total Extract x 46.31 Let’s break this down. Gravity points are simply the “excess gravity” of the desired specific gravity reading. If you have a specific gravity of 1.070, you have what is sometimes referred to as 70 points excess gravity since it is 1.07 times denser than water. The constant of 46.31 is simply that: A numerical constant. Use this number if you prefer working in English units of gallons and pounds. If you are a metric user (congratulations for joining the rest of the world!), then you will want to substitute in 386.5 instead. Total extract is a little more complicated, but only if you’re using a mix of grains. If you are using a single grain like in single malt whiskey, then it is simply the extract value of whichever milling type your operation is closest to on an “AS IS” basis multiplied by your mash efficiency. So, for our above example using Briess’ 2-Row Brewer’s Malt, we know the “as is” extract for a coarse grind is 76.6 percent. If we’re doing single malt and assume that our mash efficiency is going to be on the low side (because we’re just starting out) at around 85 percent, then we can find the Total Extract by multiplying those two values together in percentage form. 0.766 x 0.85=0.6511 This means that our Total Extract for our proposed system using that particular barley is 65.1 percent of the grain weight. But what if we have a bourbon mash with multiple grains? Things get more complicated, but not too much. The process is similar to what we’ve done thus far. 89