Yeast slurry collection techniques

Yeast & Fermentation
1

I have had both good and bad results in the past pitching onto an existing cake.
I decided to try to get a bit cleaner sample of yeast this time around and split it into several batches.

Yeast cake was US-05 from the primary of a porter that turned out pretty well (I don’t use secondaries for normal brews). The primary was a 6.5 gallon glass carboy, so to get the cake out I decided to add water, swirl and siphon. I boiled about 1.5 gallons of water, cooled to room temp and then poured this in. I avoided most of the jellied krausen at the top of the carboy, but a small bit got into the mixture. I swirled the carboy until it was pretty well mixed at the bottom, then let it sit for about a half hour. Then I used a sanitized siphon to transfer the suspended yeast into the pot I had used for boiling the water. I put the pot in the fridge last night with a clean towel over the lid since the lid is not really air tight. Tonight I plan to decant the water out of the pot and then pour the yeast into a couple of sanitized jars.

Does this sound like a decent procedure? Should I have siphoned the water into the carboy to avoid the old krausen?

Also, I read that some brewers acid-wash their yeast to scare off bacteria- does anyone do this, and if so what’s the procedure?

2

Might be easier to start with less water, wait only a couple of minutes after swirling, then decant the liquid rather than siphoning. If you started with a half-gallon of water, you could easily divide this into three Ball jars and you’d be done at that point - just put the lid on, keep them cold, and decant the water and pitch the yeast (and small amount of trub) into a fresh batch (or a starter if it’s been more than a week or two since harvesting).

3

The reason I used a siphon was to avoid the old dried on krausen at the top of the carboy; is that krausen not a problem? I guess it just looks kind of nasty so I tried to avoid it.

4

Nothing wrong with getting a little of it in there, but just pouring the water/yeast over it won’t dislodge much, if any, so don’t worry about it.