Long time listener, first time poster - thanks to everyone who's made my beer better so far. That said, I've starter re-using yeast in the last year or so, and wanted some feedback on the technique I've been using.
I've been sizing my starters using the Mr. Malty pitching rate calculator, set for a 12-14 gallon batch. Since I only brew 6-7 gallons at a time, I pitch half the starter I've made, and then:
(1) rinse the remainder (let the yeast floc out, decant the spent wort, add a measured amount of cooled boiled water,)
(2) shake up the rinsed yeast, and
(3) re-package it in sanitized White Labs vials.
I reuse white labs vials because I know about how much space is taken up by yeast in them. Knowing that, I can approximate how many cells of the rinsed yeast I'm using when I make another starter.
Rinsing yeast from an oversized starter keeps hops out of my rinsed yeast altogether. Also, because I'm using extra-light DME for the starters, there's no flavor transfer, and I don't have to mess around my brewing schedule to go from lighter to darker beers. And, from my limited ability to tell, and small sample size, it also seems like I'm still getting the benefits that come from reused yeast (particularly clean, fast, vigorous fermentations).
I do think that there's some room for improvement in my technique: brewing a DOUBLE sized starter gives me two or three vials of rinsed yeast. If I'm using just one of the new vials at per starter, and brewing just once or twice a month, then the still-unused rinsed vials stay in my fridge for as long as a month or two, which is longer than I'm really comfortable with, particularly after multiple generations. In the future, I might just make a starter-and-a-half.
That change aside, is there anything that I'm missing? This seems much simpler than trying to separate yeast from the trub of a six gallon batch of pale ale, and easier than trying to top-crop from a carboy. Thoughts?
