Using yeast for beer complexity

Looking to Add More Complexity to Your Beer?

A lot of things add flavor and aroma to beer. Malts, hops, sugars, spices, fruits and water all contribute to the sensory aspects of your beer. Often overlooked, though, is yeast. Depending on the strain, yeast can make a minor contribution or have a major impact on the aroma and flavor of your beer. Selecting flavor-enhancing yeast strains and/or mixing yeast strains can add new dimensions of complexity to your brews.

To get ever more different flavors and aromas, we often use more than one yeast strain in a given beer and add the yeasts at different stages of fermentation.

About Bruz Beers Style

Bruz Beers is an all-Belgian-style brewery and we use many different Belgian yeasts (22 different strains last year). Most American yeasts are fairly neutral – by design. If you are making an IPA and want your hops to be the stars of the beer, a neutral yeast makes sense. Belgian yeast strains, on the other hand, contribute considerable flavor and aroma to the finished beer. Depending on the beer style (and there are a lot of different styles made in Belgium) we select yeast(s) that will enhance that style. To get even more different flavors and aromas, we often use more than one yeast strain in each beer and add the yeasts at different stages of fermentation. Done well, this results in greater complexity and a more interesting final product.

Experimenting with Yeast Strains

If you are ready to try using multiple strains, I recommend doing some experimentation on the front end.

1. First, research potential yeast strains. The Wyeast and White Labs websites have profiles of their various yeasts that provide apparent attenuation, alcohol tolerance, ester and phenol production, and recommended fermentation temperatures.
2. Pick out five strains that might complement each other.
3. Brew up a simple, lightly hopped base beer and split the batch among five one-gallon jugs with airlocks.
4. Add a different yeast to each jug.
5. When fermentation is finished, bottle up the beers, prime and carbonate them. You will now have five beers which can give you a good picture of the characteristics of each of your different yeasts. You can also blend these samples to see how well they might work together.

Tips for using multiple yeasts

1. Don’t go crazy. Start with just a couple of strains that are different but compatible with each other.
2. Add one strain in primary fermentation and add another after three to five days.
3. To boost strength and attenuation, try adding a sanitary sugar solution with each additional strain.
4. Experiment with a mixed fermentation of Saccharomyces and Brettanomyces (Brett added after primary is complete) to achieve a whole new beer style. You will have to give these beers more time to develop the Brett character.

As you experiment, you will no doubt discover some interesting combinations of yeasts that will set your beers apart from the ordinary.

Happy brewing!

Charlie Gottenkieny Brewmaster at Bruz Beers Denver, CO