Airlock with Sound?

[wired247]

That yeast doesnt really drop until it nears terminal gravity at which time the yeast are struggling to survive on the remaining sugars . Within a few days after that it gets crash chilled and the yeast cake compacts. There really is no time when there is a warm cake of yeast sitting on the bottom. With convection currents and the yeast producing CO2 and swirling all over the place I seriously doubt there are more than a few degrees of temperature difference throughout the vessel at any time.

Ive probably produced 600,000-700,000 barrels of beer as a cellarmaster in a good sized micro brewery and millions more in a big-ish regional medium large brewery. Ive never seen hot spots that would be sources of autolysis. If anything is going to cause yeast derived off flavors in a brewery its going to be mutations in the yeast from too many generations of use and excessive washing.

 

[JKoravos]

I'm not saying anything about autolysis or that leaving your beer in the primary is bad. It's not. I've done it myself when I have a backlog (and like Yooper, I don't secondary either - just right to keg). I'm simply saying that it's not as necessary as people are now led to believe.

Autolysis doesn't happen that quickly on a homebrew scale, though. Production breweries make multiple barrels of beer at a time, and generally ferment in cylindroconical fermentors. The geometry of the fermentor coupled with the added pressure on the yeast builds heat much easier than the flat coating and surface exposed yeast that occurs in a carboy or bucket. Even conicals on a homebrew scale don't generate enough pressure to build up heat that significant.

tl;dr: Autolysis is a concern in commercial production, but not often in homebrew.

I think the point is that, even if the temperature of the vessel is maintained, there's a big cone of yeast sitting at the bottom of the vessel. The yeast in the middle of the cone are going to be generating their own heat and so are going to be significantly warmer than anything else in the vessel.

Two points. One, the brewer in question has multiple cooling zones on their fermenters so they can keep the yeast in the cone cooler. Two, the taste testing was done on bottled beer that had been bottled conditioned. They take the beer out of the primary within a few days.

I don't believe homebrewers with good practices need to worry about autolysis, but I also don't believe it's not a factor at all. Homebrewers who are striving to achieve quality and control of a commercial level brewery need to at least know it's there.

 

[Boleslaus]

Not true at all. It seems this whole "yeast cleaning up after themselves" thing has really blown out of proportion. Yeast shouldn't need 3 weeks to metabolise anything post fermentation. Once fermentation is complete (which should be within a week since you're pitching enough healthy yeast, right? Right.) yeast only need about 2-3 days to metabolise these byproducts of fermentation.

Diacetyl takes roughly 2 days to be rid of (and let's face it, if you are pitching at the proper, cool, temperature that you should be, diacetyl shouldn't be a concern). Acetaldehyde is the same thing - it's a precursor to ethanol, so if you're having too much green apple flavor, you aren't getting a complete and healthy fermentation. Same thing goes with fusel alcohols. If you have a good fermentation, then they shouldn't be there in the first place.

Well I'm still fairly new (1 year). I understand that the autolysis thing isn't as big of a deal as some people say. But I guess just from reading this forum, I always thought that beer needed 3 weeks.

 

[JKoravos]

But I guess just from reading this forum, I always thought that beer needed 3 weeks.

Nope.

 

[wired247]

My last few 1.060-1.074 beers were completely finished in under a week ( 5 days on one ) and were in the serving kegs in 10-11 days. Lots of O2 in the wort and a 4-6 hour yeast starter in the same gravity wort the yeast will get pitched into and it will take off roaring.

 

[Boleslaus]

Nope.

Well I've been reading this forum for quite a while now, and its generally 3 to 1 in favor of 3+ weeks. I've been more in the 2-4 crowd.

 

[Yooper]

Well I'm still fairly new (1 year). I understand that the autolysis thing isn't as big of a deal as some people say. But I guess just from reading this forum, I always thought that beer needed 3 weeks.

Nope.

Right. Beer NEEDS a few days to ferment out, and you get better beer if it gets a day or two to digest some of its own waste products. I like it better if it's had some time to clarify.

But a well-made beer never need to be in primary more than about 7-14 days.

Well I've been reading this forum for quite a while now, and its generally 3 to 1 in favor of 3+ weeks. I've been more in the 2-4 crowd.

I doubt that it really is a 3-1 margin in favor of 3+ weeks. I'd say it's just a very vocal minority.

 

[Boleslaus]

I like it better if it's had some time to clarify.

I guess that's why I've been leaving it in longer.

 

[Accidic]

I'm gonna hook a duck call up to mine.

I used a paper horn with the little roll up end torn off before to the delight of my daughter. They fit perfectly/snug on the end of an S style bubbler with no modifications. I always use cheap rockgut vodka to fill the airlock anyway so I figure if anything came off the horn it would be killed by the vodka. Anyway, it sounded like we had a dying duck for the first couple days and it was just funny (you know, to me and the 5yo... the wife didn't find it funny AT ALL).

 

[Revvy]

I used a paper horn with the little roll up end torn off before to the delight of my daughter. They fit perfectly/snug on the end of an S style bubbler with no modifications. I always use cheap rockgut vodka to fill the airlock anyway so I figure if anything came off the horn it would be killed by the vodka. Anyway, it sounded like we had a dying duck for the first couple days and it was just funny (you know, to me and the 5yo... the wife didn't find it funny AT ALL).

oooh. You have to brew an ordinary bitter and use burton ale yeast that will sound like a flock of ducks coming in for a landing.