So, let’s see. I have stuff to do this afternoon–an afternoon/dinner appointment I put off a bunch of times, but which I really need to keep today–but I swear, when I get home today, I will rack the Gentle Haejeok Oatmeal Stout to secondary to let it clear. I’ve promised a few people samples of the yeast, because it’s a famous one–“Cry Havoc,” the yeast used by homebrewing legend Charlie Papazian. (Who’s on Twitter, yo!)
The neat thing about Cry Havoc is that it works as both an ale and a lager yeast, depending on the fermentation temperatures you choose to use: if you want an ale, ferment it warmer. If you want a lager, ferment it colder. It’s that simple!
So I need to pick up a few smaller jars in which to place the yeast samples for the guys at Homebrew Korea who asked for some. (I also have some Brett C. I plan on bringing along. Unfortunately, my Belgian yeasts are in need of being used, and I mean with a quickness. So I think I’ll dump the Cry Havoc slurry into a couple of jars and pop them into the public fridge in the lounge (which is quite new, and little-used, thus cleaner than any regularly-used fridge could be). My top priority at the moment is getting the sample from my Belgian Abbey I yeast cake working on something new. So I think Wednesday, I’ll not just be mazing (making a mead) but also brewing up a Dubbel, along similar lines to my last Belgian Dubbel, but hopefully it will actually turn out to be a Dubbel this time and not some sort of impossible-to-carbonate, yeast-poor pseudo-Quadrupel.
(About which, I’m wondering whether the problem isn’t just that the yeast hit its maximum alcohol tolerance and died. That would explain why there’s so little active yeast in each bottle. For the record, I added a bit–in some cases, a fair bit–more priming sugar, along with a milliliter of Abbey I yeast, to each bottle of my limping, undercarbed Dubbel. I have learned a lesson: high alcohol beer that sits too long needs to be re-yeasted in a bottling bucket prior to bottling for refermentation. But I did not boil the sugar in water, so the beer is the same level of alcohol; if Belgian Abbey I has the same alcohol tolerance as Belgian Abbey II, my adding yeast might not make any difference. Though, from a quick look, it looks a lot more carbonated now, eight hours after re-yeasting, than it did last night. Time will tell, I guess!)
Oops, I realized the original purpose of the post was lost in all my obsessing about the condition of my various yeast samples. So…
A lot of homebrewers like to pitch yeast straight onto the yeast cake of an already fermented beer, when they rack it to secondary. One can leave a little clean beer on top of the yeast and let it sit over night, according to a lot of brewers. Indeed, if I weren’t in a hurry to get my Belgian yeast back in action, I could quite easily see myself using Cry Havoc this way–collect some samples, and then pitch the next beer onto about half of the remaining yeast cake. I’ve never had a problem.
But of course, there’s dead yeast in there. There’s trub, and gunk, and the odd bits of hops that getthrough the false bottom of my Mash/Lauter Tun. (Which reminds me, gotta get a braided hose to cut that down to zero!) The fact is, it’s “clean” in the sense that there’s much less of a chance of some kind of weird bacterial infection getting into your yeast sample… but it’s not really “clean” like we’d like for brewing.
So one thing you can do is, once you rack your beer to a carboy for secondary, you have some clean, sterile (pre-boiled) water on hand. You dump that into the fermenter straight after racking your beer to secondary, and swirl it around, and then you either pour, or pump, or use the spigot on your bottling bucket (if you fermented in that) to get the slurry into a few sample jars.
Another thing you can do is use a sterilized ladle, to get a nice thick sample of yeast cake into your jar. You’ll still want to add sterile water, or beer if you’re storing the yeast for a bit, but this way, you’re not diluting your sample right off the bat.
Once you’ve got that, put it in the fridge. Let it settle out, and then when you’re going to use it, decant the beer off the top, add some sterilized water, and swirl it so it’s easier to pour. You can leave it for a couple of weeks this way, or you can also start it off fermenting again by making a starter, like I will be with my Belgian yeast tonight. You probably don’t need to make a starter if you’re working with the yeast again in a week or two, but longer than that, you’ll want to “wash” the yeast, which means decanting, stepping up, decanting, stepping up, and so on.
Some people will tell you which layer of yeast is the one you really want. I’m not quite sure how one gets an exactly layer when one is pouring from one jar to another, but some people seem confident that they can. All I know is, if you take a sample of, say, a quarter or half of your yeast cake, and then feed it a bunch of nutrients and some fresh wort or sugar water or whatever, you’ll have half the trub of the original sample in a bigger cake of yeast. That’s enough for me to justify the trouble.
If anyone has a better way of harvesting yeast, I’m all ears!