In this episode, we talk about Barley and what to look for in selecting the variety you use for fermentation. Dylan Mobley from Bottle Logic Brewing in Anaheim, CA is the interview and we discuss how their brewing process works.
To kick off this series on fermentation bases I wanted to start with Barley since it’s used in pretty much every whiskey and beer which makes it relevant to pretty much everyone reading this but I’m only going to look at the use of barley for distillation. For the most part, malted barley is used in all applications of barley so that its diastatic index can be used to convert the starch from itself or other grains into sugar. Un-malted barley does have some of those enzymes and can typically convert itself but doesn’t have the power to knock out all of your other grains without help.
The enzymes that we’re looking for are primarily alpha & beta – amylase. Alpha-amylase converts pieces of starch chains to dextrins and reducing wort viscosity. The viscosity reduction is a byproduct of the creation of the dextrins because the longer carbohydrate chains linking is one of the causes of viscosity and by breaking them down into the shorter chains we’ll get less viscosity. The Beta-amylase primarily works on the dextrins but it also works on the ends of the long chains, just not as effective since the dextrins will have more ends for the Beta to access. The beta turns the dextrins to maltose which can then be converted by the yeast into two glucose molecules.
Each of these enzymes works best at a particular temperature and pH range and while there is some overlap between their effective ranges overall, they will work better if there is a pause in the sweet spot for each. These are your rests and the alpha rest should be at 155-167 F and 5.3-5.8 pH for maximum efficiency and the beta rest should be at 130-150 F and 5.0-5.6 pH. It’s easy to see how people would want a single rest in the 150-155 F and 5.3-5.6 pH range you may want to see if two separate rests are faster for you than one longer rest. If you are purchasing your amylase you may be given a range that is different than these and I’d go with your manufacturer. If you are using natural enzymes then keep in mind there are more things going on than just these two and by tweaking your temp and pH slightly you may get more effective results if your barley is higher or lower in limit dextranase by getting the temperature and pH close its optimal range.
Like a lot of grains there are two growing seasons for barley there is a winter season and a spring season and two types a two row and a six row. In the US the spring barely is primarily used while in Europe winter barley will be used as well, on the other hand, Europe uses two-row for brewing and distilling while six-row is typically cattle feed. In US distilling the six-row is common and two-row is used as well. Spring barley is typically planted between March and June and harvested in July to September while winter barley is planted in September to October and harvested in June. The difference between two & six-row barley starts off at the obviously physical level. There are two opposite lines of kernels running up each stalk in two-row while six-row has four main rows (two opposite two) with two smaller end rows.
Barley is primarily used for its enzyme content because it has the lowest starch content of any major grain so while you’ll get great conversion on your malt whiskey you’ll be much less alcohol at the same usage rates. If you compare this to corn which has the highest rates you’ll get barley is about 63-65% starch while corn is 72-75% starch. The easy way to tell what the starch level of your barley is to look at its nitrogen content a high nitrogen level will mean a low starch level but it will also mean a higher diastatic index so you can use the nitrogen content to decide what to use that particular barley crop for. If you’re using barley to convert your other grains then look for a night nitrogen content if you’re doing an all barley fermentation then you want a low nitrogen content so you can maximize your yield.
I like looking at nitrogen because the question of two-row vs. six-row has been mostly settled in favor of the who cares camp since modem crops have erased the major lines between the varieties you need to know the nitrogen level to know what you’re getting. If you like six-row but want to two-row properties you can go find it. I’d suggest starting with what is grown near you since it’ll have the lowest cost and probably widest selection. Two-row is primarily grown in Montana, Washington, Idaho and Colorado you can find it grown in many other states but those are the largest producers. Six-row is grown North Dakota and Minnesota with South Dakota and Idaho trailing by a good margin. Either of these can probably be found somewhere near you so if you’re not in a major producing state contact your agricultural extension and find what’s being produced near you. If you’re buying from a large producer this is where you’re likely getting you grain from.
Aside from choosing the type that’s close to you let’s look at some of the other differences. Two-row is very easy to mill due to the uniform size and shape of its kernels. Since there isn’t a lot of difference in kernel size two roller mills make a lot of sense since everything should break down evenly and you won’t need multiple roller spacings. In six-row barley, the end rows are smaller than the main rows so the additional rollers are helpful in ensuring that everything gets crushed evenly. Due to the additional kernels on the stalk six-row tends to have smaller kernels and so even if you’re just going back and forth between two and six-row it’s a good idea to adjust your mill. Smaller kernels also mean a larger percentage of the total volume is taken up by the husk. Husk can be a good a bad thing for your spirit. It tends to impart a fuller texture to the spirit due to increasing the tannin content but it also can make the spirit astringent if the husk is broken up too much, so watch those hammer mills. Six-row barley tend to have a higher protein content then two-row and higher protein mean more enzymes but less starch so faster mashes but less alcohol you will also see more foaming problems.
While it has mostly been bred out of modern barley varietals ethyl carbonate is a concern in historic strains. Ethyl carbonate is regulated by the EU but not by the US but since it still causes funky flavors it should be avoided. Biologists have isolated a precursor to ethyl carbonate that forms during fermentation and basically, that is a high GN (glycosidic nitrile) which can turn into the ethyl carbonate during fermentation. It is fairly easy to test for GN with standard tests and so before you spend too much time looking at a heritage breed get it tested so you don’t run into future problems.
Not all barley is malted and using un-malted barley can allow for some different flavors then you would get from a malted cereal. The downside comes in that the beta glucans haven’t been toasted and so these gums tend to make the wort even thicker than it normally would be. Adding a protein rest to unmalted barley or for that matter six-row fermentations can decrease foaming problems and make working with the wort a bit easier.
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Mentioned in this Episode:
Bottle Logic Brewery: bottlelogic.com
Check out other episodes of the Distilling Craft Podcast here.
