So, I washed some yeast. Now what?

I brewed a Dead Guy Ale clone about a week and a half ago, and used Rogue's Pacman yeast strain. Figuring it was on a limited release, and my love of Rogue's brews, I decided this would be a very good time to give yeast washing a try. I think it went pretty successful. I filled four one quart mason jars full, although the last one has a lot more trub in it than the other three, so I think I may dump that one.

Anyway, onto my question. What is the proper way to make a starter from washed yeast? I have a 1L erlenmyer flask that I do starters in, so pouring a whole quart in there isn't an option. Also, I assume I want to avoid putting as much trub in the starter as possible. So, what I'm wondering is, what is the most effective way to get the most yeast possible into the flask with the starter wort, while leaving as much of the other stuff behind?

Here's a picture of the washed yeast I plan on using:



I assume the white layer above the trub is what I want to get into the flask. How to get that while leaving the trub behind is where I'm stuck. I'm sort of thinking my only option is to get everything in the mason jar into suspension, and then pour some of the muddy liquid into the flask, and throw the remainder out. Or, is there some surefire method that I'm overlooking?

You're exactly correct. Pour most of the beer off, leaving enough to swirl to suspend the white yeast layer. Swirl, and decant again, leaving the trub behind. Given the option of leaving some yeast with the trub or getting a little trub into the washed yeast, take the trub. It's not detrimental in such small amounts.

The tan layer on the bottom is the trub and the white layer is the yeast.

That's not much trub really. I would just pour off about 4/5ths of the water and swirl the yeast off. If you do it slow enough you may be able to leave most of the trub behind...then dump it into a new starter.

Or you could drain off the beer and fill with boiled and cooled water and shake it up good and then let sit for 10 min. Then drain and keep the liquid/yeast suspension pouring until you start to see the darker trub start to pour out. I did this about three times and ended up with next to nothing of trub left.

That is if your not going to put it into a started right away.

Don't fret over the trub. Based on your picture, you have very little. Pour off the liquid as suggested, swirl up the contents in the bottom and add it to your 1 liter flask with sterile wort. Into every beer some trub must fall!!

Dr Malt

I ended up doing what seemed like the simplest of the suggestions; I poured off most of the liquid, swirled everything else into suspension, waited about ten minutes, and poured what I could into another jar, trying to leave the trub behind. Of course, I left some yeast behind, against Yuri's suggestion to err on the side of a little trub. REgardless, I got the starter going last night, and this morning, everything's churning along just fine. There's even some krauesining this time!

One question, I upped the DME used in this starter. Instead of 1/2 cup, I upped it to 3/4 cup, in 650 mL of water. Does anyone know a method, formula, whatever, where I can calculate how much the yeast will multiply in this wort? I wish there was a way to predict how many yeast cells I pitched into the starter...oh well.

I think he bases this on a 1.040 OG starter but it will give you most of the info that you need.

http://www.mrmalty.com/calc/calc.html