So is it as simple as taking a scoop of the yeast cake and adding it into a sanitized jar to keep in the fridge? If there are no nutrients in the jar for the yeast, will this be a problem for long term storage?
Yes, it really is that simple. And yes, there are problems with long-term storage. The harvested yeast should really be used within seven days, tops. If you plan to store it longer-term,
wash it.
Also, is there anything wrong with using parts of a yeast cake that was used in a secondary which had dry hopping? I doubt that anything outside of getting a little extra aroma would occur, but just wanted to make sure.
Don't use the dregs from the secondary. First, as you note there's usually too much non-yeast material. Second, there's not as much yeast in the slurry.
Sorry Bob, but pitching onto a yeast cake is fine in virtually all circumstances unless you are pitching a very low gravity wort. Pro brewers I've spoken with pitch on cakes all the time and will only split the yeast after a couple of batches. I think maybe they might know a thing or two about yeast. You might want to do a little research before you throw out an always... no offense.
No offense to you, old top, but that information flies in the face of almost two hundred years of fermentation science. I
have done quite a lot of research, thank you, and all of it points to me being right. Everyone from Fix to Bamforth to homebrew icons as Jamil support me.
Where's
your support?
Speaking
as a professional brewer, I cannot imagine the pro dumb enough to suffer this practice in his brewery. The professional small-brewery practice is to harvest yeast from the cone of a conical fermenter and re-pitch a measured amount into the next batch. This practice can, without washing or other more-advanced care of the yeast, be extended to ten or more generations. In professional practice I can get between ten and fifteen generations, depending on strain.
If you truly understood yeast, its life cycle, and the impact of that life cycle on beer, you wouldn't say this sort of thing.
I don't get why the fermenter is "nasty", it should be no less sanitary than when the first wort was tossed in unless you are somehow contaminating in the transfer process. Please explain why it's "bad practice".
Be glad to. It's nasty because if it's not visibly clean, it's dirty. Good practice means keeping your brewery (or at least your equipment) scrupulously clean. Hell, even Papa Charlie knows that!
A thing is either clean or it is not. If there's a stain on your shirt, it is not clean. If there's mud on your windshield, it is not clean. If there's krauesen glued to your fermenter, it is not clean. Visible soil means it cannot possibly be sanitary. Just ask people who work in operating rooms.
If you are going to go with the 'overpitching' line, please also explain the detriments and when you cross the line to 'overpitching'.
Be glad to. The two most obvious are off-flavors. First, yeast material in excess quickly leads to autolysis, which has flavor by-products which have very low flavor thresholds. Second, tasters have observed thin beer, beer lacking in body and mouthfeel. Third, suppression of esters. Yeast rely on the growth phase to reproduce enough cells to fully colonize the wort. In that phase, they use malt-based nutrients and the oxygen you provide during aeration to synthesize the components needed to build new cell walls. While they're reproducing they're producing esters. All yeast produce esters, even lager yeast, and all beers benefit from ester production (yes, even lagers). Just because you can't taste as much ester from WLP840 as you can from Ringwood doesn't mean that WLP840 doesn't throw esters! Esters are
necessary to beer, theory about "clean yeast" be damned.
When you overpitch the colony doesn't need to reproduce. Thus measurably fewer esters are produced. This, while always detrimental to beer flavor, is more pronounced with certain more flavorful strains, like Belgian strains.
The brewery where I served my apprenticeship was a Ringwood brewery. More than a dozen styles were fermented with Ringwood, including styles like American Pale Ale and Wee Heavy. If you know yeast, you know Ringwood is
very flavorful. In order to brew those styles, styles which should have very little detectable esters, we deliberately pitched more than we needed, thus suppressing ester formation. By manipulating the cell counts at inoculation we could produce the same flavor effect as switching strains entirely. GABF, WBC and the late Michael Jackson (not the one with the glove) noted the positive effects of our Good Practice in their appreciation of our beer.
As noted in Brew Like a Monk and other books, some beers benefit from slightly underpitching, because ester production is encouraged. It all depends on what you're trying to do.
I realize I probably shouldn't make blanket statements like "always" or "never". Since, however, in this case I have the fortunate circumstance of being right, I'll stand by it.
Regards,
Bob