I tested 3 samples of the strain Lachancea thermotolarens from the USDA last year. Lachancea thermotolarens is a very interesting yeast and I suggest reading my overview if you want to explore it in more detail. I also explored Pichia kluyveri, Candida zemplinina, and Hanseniaspora uvarum. Just search non-Saccharomyces on the site or look for a link below. The Lachancea strains were a little slower and they definitely had a sour note but, they had spicy and fruity characteristics too. I followed a similar approach to my other trials when testing these yeast strains.
I used a blend of later ripening apples (40% Arkansas Black, 20% Querina , 15% GoldRush, and 15% Super Yellow) making three 1-gallon fermenters. The juice was treated with pectic enzyme and racked off after clarifying. I included 125 grams of the Arkansas Black apple peels in each fermenter. The Lachancea thermotolarens yeast (Y-8284, Y-1978, and Y-2232) were added after having propagated them using my standard method. The specific gravity started at 1.064 for this mixture and the pH started at 3.50. I monitored the ferments using my Tilt Hydrometers.
The ferment started much sooner on all three with the gravity dropping by 5 points on the second day. However, the fermentation slowed and after 20 days and still had 13-24 points remaining depending on the strain. After racking and storing in kegs for another 37 days, the gravities had dropped another 10-15 points. I also checked the pH and noticed that it had dropped with all three strains. This was expected since Lachancea is known to produce lactic acid and increase acidity. What was interesting is that one strain only dropped from 3.5 to 3.33. This may have been caused by either less lactic acid being produced or some malic acid being converted to lactic acid, a trait found on some strains. I prepared the cider for bottling by force-carbonating to 2.75 volumes and aging another 20 days. I have enjoyed all three ciders. The Y-2232 is smoother and less acidic even though it had less residual sugars. I believe it is from the lower acidity (higher pH).
| Strain ID | Ferment Days | Final Gravity | Clarity | Aroma | Taste |
|---|---|---|---|---|---|
| Y-8284 | 20 | 1.024 | Slight Haze | Sour | Sour Cherry |
| Y-1978 | 20 | 1.017 | Slight Haze | Spice | Fruit Punch |
| Y-2232 | 20 | 1.013 | Slight Haze | Citrus | Sour Citrus |
| Strain ID | Ferment Days | Final Gravity | pH | Clarity | Taste |
|---|---|---|---|---|---|
| Y-8284 | 57 | 1.009 | 3.15 | Clearest | Sour Cherry |
| Y-1978 | 57 | 1.007 | 3.14 | Slight Haze | Sour Apple |
| Y-2232 | 57 | 1.001 | 3.33 | Clear | Citrus |
I harvested these yeast and pitched them again including a batch in the this year’s harvest. They continue to produce fruity and sour notes though Y-2232 is much mellower. Overall, I deemed this trial a success. I used Fermaid-O in the propagation of the yeast but, I didn’t use any nutrients in the fermentation. This year’s batch, I added a full dose of Fermaid-O with the yeast. Remember Fermaid-O is an organic nitrogen, which is the type of nutrient you want to use as it improves aromas while also providing nitrogen and other metabolites to the process. I found it interesting that the yeast has some natural residual sweetness. I am focusing on doing additional tests with Y-1978, “Sour Apple”, for now. I plan to offer it in a cider yeast trail pack. If you are interested in trialing some of these yeasts with me, check out the Cider Yeast section of The Shop & Recommended Products Page to see what is currently available.
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