I wouldn’t say no facts at all. I think if you have marginal yeast health (would have been common decades ago), adding a high proportion of corn sugar would increase yeast stress because corn sugar has no nutrients. That would increase acetylaldehyde production - and the decreased malt flavor and body would only make acetylaldehyde more obvious. This could have been made worse by poor quality malt that was lower in nutrients that what is available now. So it’s not pure fiction, just advice whose time has passed. Nowadays we pitch plenty of high quality yeast that can handle a good portion of simple sugars.
Two reasons.
First, once you start pushing above about 20% sugar, yeast nutrients might become an issue, and weak fermentation due to poor nutrient levels might be a cause of acetaldehyde. More typically, however, you have to go to something ridiculous, like 40% sugar, to start getting insufficient yeast nutrients.
Second, large quantities of adjunct sugar can impart a “cidery” quality to a fermented beverage, although this isn’t necessarily due to acetaldehyde.
What do you consider “large quantities”?
So I took the kegs out of the cooler and left them at 65F for 8 days, then put back in the cooler and reconnected to CO2. (The kegs were still pressurized, which was excellent). After4 or 5 days to chill down I sampled it again. The aroma was not so overpowering, but still there, and mildly unpleasant, and a little sulfury as well now. However after 10 minutes in the glass the aroma had largely dissipated and the beer was certainly drinkable, and an added wedge of lemon helped as well… so it’s not one to pour down the drain, but also not one I’m planning to send to any comps…!
I took a sample over the weekend to the reputable owner of my LHBS; he’s got a New York State Homebrewer of the Year award under his belt from within the last 10 years as well as a raft of medals from NHC and other local comps. He also detected the sulfur, but agreed that after 10 minutes it was largely gone. He suspects an infection, possibly from my yeast storage & transfer (I repitched T-58 from a Belgian Wit, and he also thinks a little bitter orange & coriander flavor got into this Blonde, which may be true but isn’t really the cause of the weird aroma).
In any case the guy’s big concern was that I’m re-pitching slurry from dry yeast; he emphatically said this is a no-no. I’d never heard that before, but he explained something about dry yeast being not as pure a strain as liquid and so with every re-pitch you get a higher chance of non-pure yeasties propagating weird stuff… I’d never heard this idea that re-pitching dry yeast is bad… did I miss something or is this guy, whom I otherwise quite respect as a brewer and business owner, off the mark?
red
A few thoughts based on my experience:
Sulfur always disappears with age. Give it time and it will go away.
Repitching yeast from any cake, whether originally from dry or liquid, shouldn’t matter – yeast is yeast. Right??
You didn’t warm up enough to get rid of acetaldehyde. It boils at like 69-70 F. So 65 F wouldn’t do a lot of good.
Off the mark. There was a thread in the AHA forum about how brewers have been fooled by advertising of 100% yeast by a liquid yeast company to believe that liquid yeast is purer than dry yeast. If you can get a spec or typical analysis sheet for liquid yeast it would be about the same as dry yeast. Also your friend may be remembering issues from dry yeast in the past.
When I hear people repitching dry yeast, I used to think why. But dry yeast has been going up in price a lot recently except for T-58 …