Saved a slurry of WLP 013.
Any useful techniques on how to deal with the slurry before I re-pitch into fresh wort?
I typically add a cup of distilled water and allow to separate. Decant the beer/water and repitch the slurry. Some go through the entire washing process, but I have not been that far yet. This has worked well for me for a while but I’m looking forward to other thoughts on this process…
Dave
How much do you have, and how long are you going to store it before re-pitching?
How old is the slurry?
If it has only been a week or two then it will be okay to repitch the slurry, but if it’s been longer than that I recommend making a starter. I like to rinse the yeast cake upon harvesting to remove any trub or hop particles to mitigate any potential bacterial infection. I use boiled water (chilled) water for rinsing.
I’ve already got the yeast decanted in the fridge. When saving yeast from the carboy I used boiled (and then chilled) water before transferring to the storage containers. Total volume of slurry is probably around 3 cups. At this point it’s been in storage for two weeks. To “rouse” the slurry with a starter, how big of a starter would you make?
I recommend adding some wort (1.04) to the slurry about a couple of hours prior to pitching. Add about a quart of wort to the slurry at R.T.
at risk of hijacking I have a similar question.
I have about .5 gallons of slurry/beer from a low gravity ale with WYeast 1968 that I harvested from my last batch. Poured it into a 1 gallon jug and shook it up to get everythnig back in suspension but there is no noticable layering. Just about a quart of uniform beige sludge. This yeast is like cottage cheese and it doesn’t seem to want to rinse. any ideas? should I just keep the whole thing?
If you’re going to be pitching it in the next week or so I wouldn’t bother with a starter. Just pitch about 75 mL of packed slurry per 5 gal of average-gravity ale.
That’s an interesting thought. Is your concern that the trub might be contaminated (which seems unlikely since it’s been boiled), or that it might be a food source for bacteria?
IMO, The latter…I like to keep out any potential competition. If the significant portion of the slurry is yeast and water, there is a lot less potential for bacterial contamination and off flavors.
In this situation I would just pitch the entire slurry after crash cool and decanting.
Wow. 75 ml of slurry is slurry is enough to do the job?
I should modify my above post. I would not pitch .5 gallon of slurry. I would decant, and probably separate in to two containers. Pitch one and save the other for the next beer…
Dave
A white labs vial has a “Net Volume” of 35 mls, so you’re over twice that. That is plenty for an average gravity ale. For stronger wort or a lager you’d want more.
Great info. Then is the only benefit to pitching right on top of a fresh yeast cake the speed with which the job will get done?
It will get done faster, but you may lose some yeast character. About the only time I would go right on top of a yeast cake is if I was brewing some kind of massive beer and needed to do a 5 gallon starter. Also, if your slurry is old you should use more or make a starter.
Why do you think theres any contamination in a trub or hops? If there were you’d see it growing in the beer.
So then when making the starter, would you use the whole slurry or just the 75 ml slurry?
It would depend on the wort it was going into and how old the slurry is. The older it is, the more you’ll want to use in the starter. The stronger the wort is, the more you’ll want to use in a starter. I’d look at the Mr. Malty calculator to get an idea, I don’t use it as gospel but it will give you a good idea of how much to use.
Question about making the starter, is it cool to just do as bluesman suggests? Or do you want to make the starter and let it “build up”?
It’s another question of how old the slurry is. For an older slurry I would make a starter a couple of days ahead of time, cool it and decant. You can still add some fresh wort a couple of hours before to get the yeast going prior to pitching.