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ne of the things that I enjoy about homebrewing is the science behind it. You can, if you prefer, completely ignore it and focus on the artistic side of brewing. You can also fully embrace the science and engineering side, focusing primarily on numbers and measurements and targets. I prefer a middle ground, a layman’s (or lazy) science approach if you will, where I enjoy knowing and experimenting with some of the science, but not to the point of stressing about it. Overall, this approach is driven by curiosity. I wonder what a beer would be like with one aspect modified, or how one yeast would compare to another. Simple one-to-one comparison is a great way to learn because it lets you focus on one difference between two items. This monthly column will feature ideas for semi-scientific/technical brewing projects that you can do on your own, or with a small group of friends to learn more about brewing. The point is less to make a delicious beer than to brew something with no off-flavors that features the element you are trying to learn more about.

SINGLE YEAST

In the last installment, I outlined a simple

single hop project

. Today, we’ll review comparing two yeast strains. With literally 100+ yeast strains to choose from, from several high-quality providers including White Labs , Wyeast, East Coast Yeast Safale , and Danstar , yeast choice has the potential to be an overwhelming process. Luckily, beer styles typically have a fairly strict definition of which strain to use, and since most homebrewers brew to style, the choice can simply come down to which company to go with. But you may be wondering, how much does the yeast contribute to flavor anyway? The answer is, in short, that there is no answer! Some yeasts contribute very specific flavors, and others are designed to specifically not produce any noticeable flavors. Some styles of beer achieve their flavor primarily from the yeast, others from the hops, and still others from the grain. Yeast produces different flavors at different fermentation temperatures and levels of health. The spectrum is in some ways mind boggling, and it’s no wonder that many say beer is a more complex product than wine. There are simply more ingredients, with more variables.

To start us off, I’ve designed a simple recipe with a simple test. We are going to compare two very common yeasts that get used in several common styles of beer. For the first batch, we’ll use

White Labs California Ale Yeast (WLP001)

. And yes, we’ll be using liquid yeast for this project. Dry yeast has come a long way in terms of quality and variety, but in general I’ve found most dry yeasts to be of the clean-finishing type. You really need the live culture of liquid yeast to get at some of the other esters (flavors) produced by yeast. So what will be comparing this incredibly popular and common yeast against?

How about

White Labs British Ale Yeast (WLP005)

? What a coincidence, or maybe not... this yeast is one of England’s equivalents of the Cali yeast, very popular and used in a variety of styles. And luckily for us, it should produce a noticeably different flavor profile. English ales are often described as malty, fruity, bready, or biscuity. To be fair, this is a mild component but should definitely be noticeable. The great thing about doing this at home, as opposed to going out and comparing a commercial American ale brewed with WLP001 vs. a commercial English ale brewed with WLP005 is that we can start with a standard baseline recipe and limit the variability of other factors such as fermentation temperature and carbonation. What we’ll be left with in the end is the difference contributed by the yeast.

If you have 1-3 friends that you can coordinate this with, you could expand your comparison to also include WLP002 (English Ale) and WLP003 (Irish Ale). Among all 4 you probably won’t notice much difference, but between any 2 you should be able to detect the yeast “signature” of each. If you are going to do this on your own, simply brew two 5-gallon batches of the same recipe, and try to hold all other brewing variables similar while using the different yeast. If you have the right containers, you could also simply split a 5- or 10-gallon batch in half.

As always, the purpose of these projects is slightly technical, to compare and learn. Of course, there’s no reason why your beer can’t turn out delicious, but I’ve already introduced several constraints that limit the other aspects of the brew. In terms of the malt bill, I suggest a simple base of ~85% 2-row, ~10% Crystal 40, and ~5% Crystal 120, with a target starting gravity of ~1.065. This translates to about 12 lbs of grain and will yield around a 6% ABV beer with a decent malt profile, and in this case I think the extra alcohol is warranted to enhance the flavor. I don’t suggest going any higher than that, because these yeasts are fairly mild and the alcohol might overpower some of the more delicate aspects of the yeast. For hops, let’s go with something that simply contributes bitterness and not much else. According to the chart in my

last post

, Warrior is a bittering hop described only as “very mild”. So, use 1 oz at 60 minutes to yield about 35-40 IBUs, which is the top of the range for an American/English Pale Ale, but definitely within style. Shoot for a mid-range mash of 152-154f, and a fermentation temperature of 65-68f.

Why haven’t I provided you with a detailed recipe this time? Well, I think it’s about time you learned to create your own! After all, I’ve written quite a few posts on how to do it, and all the information you need is above. For starters, check out

Recipe Writing (P1)

,

Recipe Writing (P2)

,

Beer Smith Tutorial P1

, and

Beer Smith Tutorial P2

. And I’ll tell you what, you read those articles and give it a try, and if you still have any questions, post in the comments below or email me at

beerbyben@gmail.com

and I’ll help you the best I can! When I first started homebrewing, someone who had been brewing for many years told me that formulating recipes was one of the best parts of the hobby, and though at first I didn’t understand I now agree 100%, and I hope you’ll give it a shot too. It really is one of the most creative and fun aspects of brewing, and once you free yourself from using pre-made recipes, the world just opens up.

Look for this DIY series as a monthly feature. Future posts will discuss projects like comparing yeast strains, comparing different base malts or roasted malts, and comparing variations of a single style.