I’ve been bottling straight from primary after 2-2.5 weeks (no cold crash). Most of the time my beer goes into the bottle quite cloudy, but within hours I see yeast on the bottom of the bottle, and after 1-2 days at room temp it clears significantly, and in a week it’s crystal clear, but with a lot of yeast on the bottom of the bottle. I use a carrageenan product at 15 min to flame-out.
I’m perplexed why the beer doesn’t clarify more in the fermenter, but the yeast seems to drop like crazy once bottled. I’m wondering if the stirring action of the bottling process somehow causes the drop,and if I should maybe slosh the fermenter a couple days before bottling?
I’ve always wondered this myself. When I used to rack to a secondary carboy, I always saw the same thing. The yeast would drop like crazy once in the secondary, suggesting that settling had reached some maximum level in the primary.
I hypothesize that it’s due to the fact that yeast cells have a tiny net negative charge. Once the sediment in the primary reaches a certain mass, it has a collective negative charge that’s strong enough to electrostatically repel cells still drifting down to settle. And so these cells remain suspended. When you move the beer off the sediment, the cells in suspension are no longer repelled, and they drop like a rock.
This is purely unsupported speculation on my part, but seems like a reasonable possibility.
I’ve also seen this multiple times after racking to secondary. I always thought the “mixing action” of racking was giving small particles in suspension a chance to bind together and then sink to the bottom. But RC’s hypothesis could definitely be the case.
How do you prime your bottles when racking directly from the primary? Gently racking to a bottling bucket moves clear beer with all the stuff left behind in the primary fermenter. This also allows more accurate addition of priming sugar and thorough mixing before bottling. This method gives clear beer and minimum yeast layer in the bottom of the bottle.
When I used a lot of US-05,I found that racking worked well to clear the beer. Got to thinking after a while that it could only be due to the agitation. Sure enough, swirling a couple of times per day after fermentation slowed did the same thing.
Thinking that sometimes the less flocculent yeast just need a kick in the a$$.