Non-Saccharomyces Yeast: Hanseniaspora uvarum Results

I was able to assess three Hanseniaspora uvarum yeast strains from the USDA culture collection for use in cider making. I provided a detailed overview on these and other non-Saccharomyces strains in earlier articles. Just search for non-Saccharomyces on the site or look in the post carousal below for the links. Hanseniaspora uvarum is a very common yeast found on apples and grapes and can produce fruity esters but, it also is known to create spicy aromas and can over produce ethyl acetate, which creates a solvent characteristic. Many strains struggle to process fructose and sucrose so having a residual sweetness is more common though wild Saccharomyces and other genera of yeast may complete the fermentation process.

I used a blend of sharp and sweet apples including Arkansas Black, Stayman Winesap, Fuji, and Golden Delicious. The juice’s starting gravity was 1.064 with a pH of 3.3, so slightly acidic given the higher concentration of sharp apples. I fermented three one-gallon fermenters with 75grams of Arkansas Black peels in each. The Hanseniaspora strains were from the USDA’s culture collection (Y-120, Y-915, and YB-249). I propagated the yeast samples using Fermaid-O and sterile organic juice. I also monitored the process using my Tilt Hydrometers, which I recommend on the shop page as a great tool for active monitoring of your hard cider.

Hanseniaspora uvarum is known to prefer glucose over sucrose and fructose so I wanted to see if it would have residual sweetness. It started fermenting relatively strongly dropping around 50-53 points after 11 days. This is slower than most Saccharomyces cerevisiae strains but I find it to be a good rate. It’s not too vigorous or too slow. After 20 days, the cider was clearing and had dropped to 1.004-1.010 but still had some activity. I aged these in kegs for another 30 days and all had dropped to 0.999 at that time. I bottled them with 2.5 volumes CO2 and sampled them after another 5 months. The Y-915 has turned out to be my favorite as it has retained the fruity apple aroma and taste. The medicinal aroma in YB-249 has remained and Y-120 lost most of its sweet and fruity notes. I definitely need to try this yeast with a less acidic juice base.

Strain ID	Ferment Days	Final Gravity	Clarity	Aroma	Taste
Y-915	20	1.004	Clearest	Fruity	Apple
YB-249	20	1.010	Clear	Slight Sour	Medicinal
Y-120	20	1.006	Haze	Strawberry	Bubble Gum

Attributes at the End of Fermentation

As with my other trials, I still think this yeast has many positive characteristics that make it a good choice for cider. I get more fruity aromas than most Saccharomyces yeasts I have used. It’s slower, even at warmer temperatures, which means more aromas are maintained and not lost due to a vigorous fermentation. I harvested the yeast from the Y-120 ferment and blended it with some Pichia kluyveri for my ice cider. This went dry from 1.099 so it may be that some of the wild Saccharomyces strains dominated the cider at the end. I need to do more trials with sterile juice and see if it performs similarly or if it retains more of the residual sugars. I continue to see more residual sweetness in the non-Saccharomyces strains, even when they finish dry. They are also more complex in aromas and tastes.

I have created some trial packs of non-Saccharomyces strains if you want to test some as well. You can find them on the Cider Yeast page in the The Shop. I also included the following button to go directly to the yeast page.

Cider Yeast Shop