Voss & diacetyl

[ebbelwoi]

I've been brewing with Voss for almost a year now, and have done a few dozen batches. Nearly all of them have been successful. The last few batches (two porters and now an American IPA) have had a slick mouthfeel. It was most noticeable when pulling a sample from the IPA at around the 7-day mark.

I've never noticed slickness in the past, but that doesn't mean it wasn't there. One major difference in my process has been fermentation temp. In the summer and early fall, it was in the mid-90s (35C), whereas now, I'm only getting to the mid-80s (28C) with a heating mat. Not much else has changed.

It sounds like a diacetyl issue to me, but I do not detect any buttered popcorn aroma from any of my beers. Neither does my wife, or a buddy who I exchange homebrews with. Again, that's not to say that it's not there.

I've only detected this slickness when using Voss. Some of my batches are probably on the 7th-8th generation by now, but I do have some 2nd-generation slurry.

I don't see anything remarkable in my recipes or process, so for the sake of brevity I won't post them, but can do if need be.

Has anyone had diacetyl with Voss before? Has anyone had diacetyl without the butteriness?

 

[bkboiler]

What kind of grains were in these last three beers?

Where do you source your water from?

 

[ebbelwoi]

Porters:
Weyermann Smoked Malt and/or Crisp Maris Otter
Crisp Brown Malt
Best Munich Dark
Quaker Oats
Weyermann Caraaroma
Weyermann Chocolate Malt

The oats at are about 8% of the grist.

IPA:
Crisp Maris Otter
Best Munich Dark
Weyermann Carapils
Weyermann Melanoidin
Weyermann Caramunich I

I use the local tap water. It's relatively soft, and I add gypsum, calcium chloride, sodium chloride, lactic acid, and sometimes baking soda to get the ion levels and pH where I want them. I use the same water in all my beers, but have only gotten the slickness when I use Voss.

The IPA tastes less slick than it did a few days ago, but it's still there, on Day 11.

 

[couchsending]

All Kviek yeasts to me produce this really weird mouthfeel... it’s not diacetyl but it is this odd slickness/texture. It’s different on the palate than diacetyl. It’s not in your face but I’ve never had a kviek beer that didn’t have it. done more than others.

I have no clue but I wonder if it’s glycerol production by the yeast due to high fermentation temps. Or it’s just some byproduct they’ve had to produce over time in order to survive in their environment???

 

[Vale71]

It's probably beta-glucans. You get them from oats too.

 

[OnePlate]

I suspect excess glycerol production. I think your Voss may have either mutated or some fermenting condition is causing excess production. I'd go back to your 2nd-gen slurry or just buy a new pack and try again to see if it goes away.