Choosing the Right Yeast: Tips from the Pros

Brewer:  Steve Anderson
Brewery:  Waterloo Brewing Co., Austin, Texas
Years of experience:  4
Education:  Completed two courses at Siebel Institute of Technology in Chicago; BS in psychology from University of Texas at Austin
House Beers:  Clara’s Clara (blonde ale), Ed’s Best Bitter, O. Henry’s Porter, Guytown IPA

The first step to choosing the right yeast is obvious: Decide what qualities you want in your beer. Browse through the catalogs of yeast suppliers. We buy from Wyeast and use its booklet to check out what various strains do. Then just try them.

When we brewed our pilsner we made it with all Czech malt and all Czech hops. So to make it as authentic as possible we used a Bohemian lager strain, 2124. It is supposed to enhance the maltiness of the beer.

We first opened when there was a craze for Wyeast 1056 (American ale). It has wonderful, clean properties, but it didn’t impart the kind of flavors we wanted for our beers. We were looking for a yeast strain that had more esters and was more English in character.

The yeast strain we use now for our house beers is Wyeast 1968 (London special ale). This strain gives us more of the English-style flavors we want such as a hint of ester and its ability to enhance the maltiness. It works well with our English-style bitter, a porter, an IPA, and a blonde ale. Using one versatile yeast for most of our beers also eliminates the need to keep other strains alive.

We wanted something highly flocculent, which 1968 is. We have cylindroconical fermenters from which we can harvest yeast off the bottom. So with the highly flocculent yeast and the fact that we use finings, too, we have no trouble racking.

Using a low-flocculating strain would be difficult for us because we have no way to clarify the beer unless we run it through a filter. Even then it’s a great pain because the filter clogs quickly if there is a bunch of yeast going through it. We try to avoid fil­tering any of our beers anyway. Using this strain makes harvesting easy because it’s all sitting either at the top or bottom of the fermenter. So for homebrewers (flocculent yeast) is very important because they don’t have the kind of filtration systems we do.

Some strains attenuate more (ferment the beer more completely) than others. But to me that’s secondary. Most of our beers end with a high gravity anyway. We like them to have a good mouthfeel. But keep in mind that attenuation is also affected by your yield, not just dependent on the yeast strain. If you want an American lager, you want a highly attenuative strain such as 2007 (Pilsner) or 2035 (American lager).

One factor to consider is how a strain does in a certain climate. Here in the South it is warm. Today it’s 75° F, perfect for brewing. But in the summer it won’t be, especially if you live in an older home with poor insulation and have to run the air conditioner to keep your beer from fermenting at 95° F. So choose a yeast strain such as 2112 (California lager) for steam beer or 1728 (Scottish ale). They won’t suffer terribly because of fluctuations in temperature. That’s why ale yeasts are most popular; they can ferment in warmer temperatures. And in my experience they are much hardier than lager yeast.

We use Weihenstephan weizen yeast for our hefe-weizen (seasonal), and the difference between fermenting at 65° F and at 70° F is tremendous. The esters, especially banana, are much higher in that high-degree range. The 1968, however, is very versatile. Although the beers I ferment at 63° F (porter and IPA) are high in gravity to begin with, the difference between fermenting at 63° F and at 68° F is negligible. But it’s even hard to tell a difference with a milder beer. I’ve fermented our bitter at 65° F and 68° F — we have fluctuations with the glycol jackets kicking on and off — and I can’t tell the difference.

For homebrewing, however, you are fermenting up to 75° to 80° F and will definitely see a difference. So if you want consistency and you are harvesting yeast, ferment at the same temperature because yeast acclimatizes to the environment from the first batch to the next.

Finally, experiment. I’m sensitive to diacetyl, but in some styles, for instance English ales such as Bass, it is desirable. So you can cross over somewhat if a strain has a character you like. You can also experiment with temperature. Look at steam beer: lager fermented at very high temperatures.

Issue: April 1998