We've all heard it before, but it bears repeating: "Brewers make wort, yeast makes beer." Regarding Brewing, selecting the right yeast strain is arguably the most crucial decision you'll make. Let's explore the world of brewing yeasts and how to pick the perfect one for your next batch.
Ale vs Lager: Understanding the Basics
In the realm of brewing yeast, there are four main groups of brewers' yeast: ale yeast (Saccharomyces cerevisiae), lager yeast (Saccharomyces pastorianus), the Hybrid strains, which can be either ale or lager but show atypical characteristics, and Wild yeast and bacteria for sour beer production. Each possess unique traits that significantly impact your final product.
Ale yeasts thrive at warmer temperatures (15-35°C) and are known for faster fermentation times, often imparting fruity flavour and aroma characteristics. These fruity characteristics from warmer fermentation temperatures are desirable for some beers but would be considered an off-flavour in other beer styles. These yeast strains can be prone to fermenting too warmly and producing hotter alcohols, which are also undesirable.
Lager yeasts prefer cooler temperatures (8-15°C) and ferment more slowly, leading to the crisp, clean taste and brilliant clarity that defines most lager styles. Because these yeast strains ferment cooler, they are prone to incomplete fermentation and can produce some sulphur notes.
The Hybrid yeasts are typically Lager yeasts that can ferment at warmer temperatures (up to 22°C). These are the specific yeast for many traditional styles like Kölsch, Altbier, Califonia Common and more recently, Cold IPAs.
There are also the wild yeast and bacteria used in making sour beer. For more on these, see our article Sour Beer Revolution: Exploring the Tangy Frontier.
Selecting Your Yeast: A Crucial Decision
The first is to decide what style of beer you want to brew which will typically hinge on whether or not you have fermentation temperature control. If you do, then the world is your oyster, and you can pick whatever style you fancy. If you don't have temperature control, then the best results will be achieved by matching the beer style to your ambient conditions. So, if your ambient conditions inside are 10-15°C because it's winter, then brewing a lager style will likely give you the best results. If your ambient temperatures are greater than 18°C, then the ale styles will offer you the best results. For more on temperature control, check out our article Temperature Taming: 8 Reasons for Fermentation Control.
You might be thinking "but I don't want to drink a crisp lager in the middle of winter". Well, there are over 100 different recognised beer styles, so you're likely to find something to make that suits the time of year. Also, don't forget that that it a month or so to make the beer before it's ready to drink, so traditionally, without modern temperature control, beers were brewed before they were needed. Use the temperatures of late winter to make that delicious crisp lager so that it is ready for the warmer months and use the temperature of late summer to make those winter warmer ales ahead of the cooler months.
In saying that, there is room to cheat a little. The hybrid yeasts can be applied to Lager styles to give a reasonable example brewed in warmer temperatures, but these are best used for the hybrid styles. Kveik yeasts can be used to make relatively clean ales when the temperatures are above 25°C.
Now that you've selected a style, you can select the yeast. There are hundreds of yeasts out there from many yeast labs. Most of these will be labelled for the style they are most suited to. For example, many yeast labs will call their hybrid lager a Kölsch, Altbier or California Common yeast, though many yeast labs will also state which other styles the yeast may be good for. Then, you can look at the flavour and aroma of that yeast and see which yeasts appeal to you. You may want to select the yeast that produces tropical notes for that tropical pale ale you want to make. If you don't have temperature control, then at this point, you will want to ensure that your ambient temperature is in the lower 2/3rds of the temperature range.
When choosing your yeast, consider your target beer style, desired flavour profile, and the level of control you have over your fermentation process. Don't shy away from experimentation – it's a fundamental part of the homebrewing journey.
Remember, selecting the right yeast strain is just the first step. For more articles on yeast, see the rest of our articles in this series:
Ready to explore more about brewing yeasts? Check out the comprehensive booklet and chart on Mangrove Jack's Craft Series Dried Yeasts here:
- Mangrove Jack's Craft Series Dried Yeast Guidebook
- Mangrove Jack's Craft Series Craft Series Dried Beer Yeast Chart
If you're ready to select your yeast, take a look at our range of brewing yeasts, here. Here's to your next great homebrew!
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