A Yeast for Every Season
Yeasts are small single-celled microorganisms classified as members of the fungus kingdom. More importantly, the species Saccharomyces cerevisiae loves to convert carbohydrates (sugars) into carbon dioxide and alcohols (ethanol mostly). There are also some other yeast species and bacteria that are utilized to make mead, wine, beer, etc., but Saccharomyces cerevisiae is king.
Within Saccharomyces cerevisiae, there is a multitude of unique strains. All of them are a little different in one way or another. The meadmaker, vintner, brewer, etc. usually selects a specific lab-grown strain to suit their needs or relies on the local yeast in the air, on the outside of fruit, or from a previous batch. Lab-grown yeasts are the norm since they allow for reproducible results time after time. Wild yeasts are a discussion for another time.
When selecting a yeast, you have to take into account the temperature you’re fermenting at, how much alcohol the finished product will have, what flavors and aromas (even mouthfeel) the yeast will add, how quickly the yeast will convert the sugars, nutrient requirements, and multiple other factors.
Many of these factors can easily be augmented to create the desired end result. However, smaller producers usually lack expensive glycol chiller systems required to dial in the fermentation temps. As a result, they are more limited on how they can control the temperature of the fermentations.
To deal with this apparent limitation, I follow an approach of selecting yeast that is seasonal in nature. As it heats up in summer, I use yeast that likes it hot. As it cools down in fall, I use yeast that likes it cooler. My best traditional meads (honey, water, and yeast) are going to be produced in late fall and through winter. The yeast strains required to make this style shine like it cool (below 60 F in some cases). On the other side of the spectrum, when the heat is blazing down here in Georgia, I break out the funky Saison and Belgian strains.
The small-scale meadmaker can easily produce incredible mead year-round, even without air conditioning, but it requires a bit more flexibility. Don’t force those cool strains out of their sweet spot. Instead, change your mead style to embrace everything that the terroir has to offer.
I am not a health professional, nor do I pretend to be. Please consult your doctor before altering your alcohol consumption habits. Do not consume alcohol if you are under the age of 21. Do not drink and drive. Enjoy responsibly!