Author Topic: Diastaticus  (Read 209 times)

Offline Richard

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Diastaticus
« on: June 20, 2019, 01:56:51 PM »
I just read the article in the latest Zymurgy "Dealing with Diastaticus" and found it to be very helpful and informative. The article mostly considered Saccharomyces cerevisiae var. diastaticus to be the result of an infection or contamination, but did briefly mention that it might come from "non-standard" yeasts. I brewed a batch of Sierra Nevada Resilience IPA in January and used one of the suggested yeasts, Imperial A24 Dry Hop. The Imperial web site says that this yeast contains a strain that tests positive for the STA1 gene and is considered to be Saccharomyces cerevisiae var. diastaticus. I read that but didn't know what the implications were. I ended up with highly over-carbonated beer. I won't be using that yeast again.

Now I need to get out the iodophor and clean everything that was touched by that yeast.
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Offline RC

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Re: Diastaticus
« Reply #1 on: June 20, 2019, 04:49:36 PM »
Imperial Dry Hop (A24) contains Saccharomyces bruxellensis, which is a wild strain. It's the same thing as White Labs's WLP644, which is a pure pitch of it (whereas A24 is a blend).

I've used A24 and WLP644 plenty of times and I've never had a problem with over-attenuation or over-carbonation in the 14 - 21 day timeline my IPAs go through from grain to glass. But I only keg, and I assume that glucoamylase activity is suppressed upon cold-crashing. I imagine I'd experience issues if I bottled the beer and let the bottles hang around at room temp after reaching full carbonation. Did you bottle your beer?

As a side note, I love these strains. Phenomenal expression of pineapple and mango esters, with a little tartness. The description for WLP644 exactly matches what I got from this yeast.

Offline hopfenundmalz

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Re: Diastaticus
« Reply #2 on: June 20, 2019, 09:10:22 PM »
3711 and some others are.
Jeff Rankert
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Offline Richard

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Re: Diastaticus
« Reply #3 on: June 20, 2019, 09:25:00 PM »
I imagine I'd experience issues if I bottled the beer and let the bottles hang around at room temp after reaching full carbonation. Did you bottle your beer?

Yes, the beer was bottled. The amount of priming sugar was based on my usual assumptions. My bottles were kept at room temperature for a couple of weeks, then refrigerated. It was highly carbonated but was manageable if poured slowly. I gave some to an assistant brewer who kept it warm for longer and had real gushers.

The taste was very good, and if I experimented enough with it I might be able to figure out how to cut back the priming sugar to compensate, but it doesn't seem worth it to me. I may or may not brew this again, but if I do I will use a different yeast. I am sure there are many that will give good flavors.
Original Gravity - that would be Newton's