Choosing Your Yeast for Craft Beer
Yeast is important and responsible for up to 60~80% of a beer’s flavour and aroma. In fact, yeast strain is often the main difference between certain beer styles. So choosing the right yeast is the first step to brew an ideal craft beer.
Nowadays, many companies, such as Angel, have collected different strains from around the world, and made dry beer yeast successfully. It provides a lot of viable yeast cells, which is almost more than 6*109/g, and can be prepared quickly on brewing day, and can be stored for 24 months in a cool, and dry place.
The appearance of dry beer yeast provides more convenience than that of liquid yeasts, and it also brings a new confusion: How to choose the right yeast from so many products.
Simply, we could just match the name of yeast to the beer style and it works well in many case. But it is not enough for commercial brewing to do this, we’d better understanding the selection process.
Beer yeast, a single celled microbe, belongs to the genus Saccharomyces, divided into two categories: Saccharomyces cerevisiae, which is often called ale yeast, and Saccharomyces pastorianus, which is called lager yeast normally. All the yeast are classed by three main characteristics: attenuation, flocculation, and flavour profile.
How much sugars of the wort the yeast can use during brewing? Some strains ferment more fully than others, and it means its attenuation is higher. Yeast that have an apparent attenuation of 68 to 72 percent will leave a lot of residual sweetness in the beer. An apparent attenuation of 73 to 77 percent is more typical, having a lower residual sweetness, and a higher apparent attenuation of 78 percent or more will produce a drier beer with a lighter body.
It represents how well the yeast clumps together and drops out of beer after primary fermentation. Premature flocculation may lead an unexpected higher attenuation. It will take more time to reduce the level of VDK, and perhaps the taste of beer will change badly.
If you want to brew lagers, a high flocculation yeast is a wise choice, while a low to medium flocculation yeast is good for wheat beer or Belgian saison styles and a medium to high flocculation yeast is good for classic ale beers.
3. Flavour Profile
What flavour they produce is the key characteristics of yeast, such as spicy, fruity, estery flavours , flower fragrance, and so on.
Do you want a little bit of fruity esters? Try an ale yeast stain that is comfortable fermenting at relatively cool temperatures. Do you want a lot of fruity esters? Probably, try an English ale yeast or Belgian ale yeast that prefer warmer temperature and produce more esters.
Here is some tips for you to choose your yeast.
Belgian Ale Yeast
Spicy, ester flavour
German Weizen Yeast
Banana, clove spiciness
American Ale Yeast
Clean, very little yeast flavour, allowing the hops and malt characters to shine
English Ale Yeast
Fruity, apple, pear
Think about the style of the beer you plan to brew. Is it a toasty, malty beer with some touches of fruity esters and some residual sweetness? Or is it a drier, crisper beer with a significant bitter edge and no esters? Or is it a complex medley of dried fruit and spicy, warm alcohol? These stylistic aspects tell you the kind of yeast you should be selecting.