Pitching On Top Of Slurry

[Buzzbeer]

I'm about to try something I haven't done before and want to check in here and see if my process to do this sounds good. I have a Scottish Ale that is finishing and I want to use the slurry to make a Stout. I'm planning to take the beer off the Scottish Ale slurry and leave a little liquid/beer so that I can save it in a sanitized mason jar. Then after brewing the Stout, I'll get it into a sanitized fermenter and pitch the whole slurry on top. So does this sound about right? I would do this within one or two days and shouldn't have to make a starter out of the slurry, right?

 

[mtnagel]

Read this first and then decide.

Personally I go with a much smaller amount based on Mr Malty's repitching calculator.

 

[mrboz]

You can do this for sure. I would be inclined to harvest/wash the yeast from the slurry. This will give you cleaner yeast to work with, will be easier to estimate your pitch rate, and will be easier to duplicate should you find that your Stout comes out awesome and you want to make it again. Just add some sanitized water (boiled/cooled) water to the slurry and swirl it up ... let it settle a bit, pour off the liquid to a large (sanitized/boiled) jar. Let this settle for 10-15 minutes (it is dead yeast and trub that is settling ... good yeast will remain in suspension longer). Pour off the top half into a couple pint jars that are about 1/4 full of sanitized (boiled/cooled) water ... then let those settle overnight. Next day, you'll see the nice creamy washed yeast at the bottom of the jar ... decant (leaving just enough liquid to swirl the yeast) then pitch the remaining yeast.

 

[LLBeanJ]

I do what you're proposing fairly frequently. Assuming the OG from your source batch was 1.060-ish or lower, use Mrmalty's Repitching from Slurry tab, as stated above, to figure out how much you need. I always use the default settings and have found that most 5 gallon batches of moderate OG wort will require somewhere in the neighborhood of 100ml (~4 oz.) slurry.

 

[sloanfamilydsm]

My last brew was a winter warmer 1.089 OG. I racked a cream ale into the keg n immediately racked the winter warmer from the brew kettle directly on to of the yeast cake from the cream ale (dennys fav 50 yeast).
Fermentation took off like a beast and in six days finished at 1.011.
Some will say over pitching yeast is bad....but it sure works good for me.

 

[Calder]

Ignore Mr. Malty, it is way too conservative on yeast viability in slurry calculations. It says that after a month you only have 10% viability (or something like that), which is clearly not right.

No need to leave any liquid, nor add sanitized water. Just move the beer, then swirl up the slurry. It should have enough liquid left in it. Once swirled up, pour into sanitized mason jars. Keep in fridge until use. In my experience, you can straight pitch if used within a month.

How much to use. My general rule is roughly 25% of the cake for a similar gravity beer. If you use the whole cake, you can make good beer, but you will be over pitching. Pitching only part of the cake should result in a better beer.

 

[mtnagel]

Ignore Mr. Malty, it is way too conservative on yeast viability in slurry calculations. It says that after a month you only have 10% viability (or something like that), which is clearly not right.

How is that clear? Have you measured?

If you don't believe Jamil, do you believe Chris White?

How long can yeast be stored? The best case scenario is to use the yeast within 1-3 days. Again, this is often not possible, especially if multiple strains are being used in the brewery. The magic number seems to be two weeks. If less than two weeks, brewers will usually have no problem reusing yeast. Over two weeks and you may or may not have problems. After four weeks, the viability of yeast slurry is usually 50% or lower.

 

[Calder]

How is that clear? Have you measured?

If you don't believe Jamil, do you believe Chris White?

1 - try pitching a quarter cake of month old slurry. If mr malty is right at 10%, you will be underpitching by about 85%; that is you will only be pitching 15% of ideal. I bet it takes off within 12 to 15 hours .......... which it woukdn't do if severely underpitched.

2 - viability at 12 months is also 10%, so while there is a large drop off in the first month (or 2m I might have the time wrong), there is no change in the next 10 or 11 months.

Your reference to Chris White is more generous than Mr. Malty.

If you think it is right, then use it. I think it is wrong, and you will be severely overpitching if you use it for any slurry more than a few days old.

 

[smccarter]

Rack your beer off of the yeast cake, then syphon about half of the slurry out of the carboy. Rack your wort on top of what's left and you're good to go.

I've done this many, many times and it's worked very well every time.

I racked on top of the entire slurry the first couple of times. The fermentation was way too agressive. Pulling half of the slurry off of the bottom of the fermenter works perfectly.

Brewing beer should be fun. It shouldn't be overly complicated. It's a hobby. Unless you absolutely know without a doubt that you will become a brew master some day, just calm down, enjoy the hobby, drink and share your beer, and have fun.

 

[wobdee]

I reuse slurry about 6 generations before going with a new smack pack. After racking the beer I gently swirl the yeast and pour into a couple sanitized mason jars. One thing I've noticed is the more compacted dead yeast and trub will be on the very bottom so I try to not disturb that and get the younger yeast on top. Never had any problems using this method for years. I usually use the yeast within 2 weeks but I'd be willing to go a little longer.

 

[brewbush]

I have been racking the beer the same day as I brew. Then when ready to add the yeast, I just open the just-racked bucket and take a sanitized glass pyrex cup and scoop some of the slurry and dump it into new beer.

If I save any more I just continue to shovel it into a sanitized mason jar.