Cider Yeast Exploration: New Strains Explored

If you have been wondering, I am still here! 😁

Besides settling into our new home and routines, I started exploring some additional cider yeasts (also known as non-Saccharomyces strains). This season, I tested two more non-Saccharomyces cultures. I used the same juice, created from a mix of “Super Yellow” rootstock, Hardy Cumberland, and Arkansas Black apples. These were harvested late in the season and my sugars were very high, around 1.090 and a pH of 3.2, so quite tart as well. I did two one-gallon (3.8L) batches with juice that I clarified by adding pectic enzyme and cold crashing overnight. I siphon off the clearer juice from the sediment and ferment. Unlike my normal process, I did not add any apple peels (next trial) or sterilize the juice in any way.

The yeast that I propagated and used came from the ARS Culture Collection (NRRL). I used Torulaspora microellipsoides (Y-17058) and Metschnikowia pulcherrima (Y-1433). Both were reviewed in research papers on wine, beer, and cider production with positive attributes. My goal is to make cider that has a natural residual sweetness, like keeving, while creating fruity aromas and a flavorful, well-bodied palate. The more I learn, the more everything points towards avoiding Saccharomyces yeast strains and focusing on enabling non-Saccharomyces yeast. However, to control the process and avoid contamination by Saccharomyces cultures, you need to inoculate with a sufficient biomass of non-Saccharomyces yeast. This can inhibit the domination of the Saccharomyces strains during the fermentation process. The challenge is finding these “cider yeasts”. Most commercial suppliers offer very limited options or quantities that are too large for home and craft cider makers.

This is why I created the Cider Yeast Page. I test and propagate yeast that can create great ciders and offer them to the home and craft cider makers. Check the page for new offerings and make sure you place your orders in early in the season. Yes, I can always propagate more but it does take time.

As for Torulaspora microellipsoides (Y-17058) and Metschnikowia pulcherrima (Y-1433), both showed promise. I was able to retain some residual sugars and create appealing ciders both visually and aromatically. The T. microellipsoides clarified much faster than the M. pulcherrima so I use it on my ice cider and it performed similarly. It has a fruity and honey aroma profile, while the M. pulcherrima has more spicy notes. Originally, the M. pulcherrima had some turbidity and was distinctly lighter in color when bottling. After sitting in bottles for a few weeks, the colors are more similar and the both have good clarity. Initially, I thought the M. pulcherrima might still be fermenting but the bottles do not have any lees, even after clarifying. My assessment is that is that it was a colloidal reaction occurring that does not precipitate out. Again, these are my first trails with these strains so I am still learning. I have started distributing the bottles to my tasters for feedback. I also already started my second trial with an ice cider using a large amount of Arkansas Black peels in the primary.

Here is the visually comparison of the two yeast at bottling and after 3 weeks. While the T. microellipsoides has remained clear and the color hue consistent, the M. pulcherrima has clarified and become more amber, though slightly lighter than the T. microellipsoides. It is interesting how yeast not only impacts aroma but color and turbidity. The T. microellipsoides has 26 points of sugar remaining while the M. pulcherrima has 14, which is consistent with my new process and the higher starting sugars.

Look for these yeast in a trail pack on the yeast page to do your own experiment. Let me know which you like better and why.

If you liked this post, explore some of the other posts on non-Saccharomyces yeast.