[benamcg]

I recently washed or rinsed (depending on who you ask) the yeast from 2 6-gal glass carboys.  I allowed the trub to settle in 2 separate jars, then transfered to a couple of secondary settling Ball jars.  What I have now is a beer/water layer on top of beautiful looking yeast.   

In the past, I pitched everything I harvested equally into 2 carboys.  However, from my rinsing it looks like the equivalent of 10 White Lab vials (not including the beer water- just the solid yeast portion).

My questions are:
1.  How much should I repitch? and

2. How do I determine if?  Weight?  If so, I could weigh the Ball jars and compare to an empty one of the same size.  Or fill an old yeast tube and pitch that into a starter.

Any thoughts would be greatly appreciated,
Thanks
-Ben

[Thirsty_Monk]

Mr malty pitching rate calculator can help you with your first question.
On your second question.
I decant my slury that I have 50/50 yeast and liquid.
Then I pitch the recomended amount from the calculator.

[b-hoppy]

i think it depends alot on how long you wait before you brew again.  a pro brewer friend of mine mentioned that you probably lose about 10-15% viability each 7 days that it's been sitting in the fridge (closer to freezing is better).  not real scientific but i've gotten away with using about 1/2 inch of sediment from a quart jar that's been in the fridge for up to 3 weeks for a 5 gallon brew of og 1060.  it's hit or miss due to not having a lab but this has worked fine for me for the last 3 or so years.  i've restarted some that sat for a year in the mason jar and it has worked fine.  when in doubt make a starter.

[richardt]

I've wondered about the "rinsing yeast", too.  I like the idea of pitching only the healthy creamy white yeast rather than the brown/green goop that constitutes the yeast cake at the bottom of the fermenter.  I notice that some veteran brewers say they pitch right onto the yeast cake or use a mason jar of unwashed (or unrinsed) yeast slurry without ill effects.  Does it matter (with regards to taste)?  Does pitching the brown/green goop that I've harvested from the previous batch mean that I've ruined the beer?

[b-hoppy]

the problem i had a few years back was increasing bitterness the longer i repitched on the the cake.  i tend to make very hoppy beers and what was happening apparently was that the hop residue was accumulating in the cake and carried over from batch to batch.  once i began rinsing the cake i find the bitterness is almost completely gone and things are going well.

[hopfenundmalz]

This is covered in Yeast by Chris White and Jamil.   You want to pitch the correct number of cells, so a cleaned up slurry is better.  It is claimed you make better beer if you don't use the trub and dead yeast.  Rinsing is using water (boiled and cooled).   Washing is using acid.  The book covered rinsing, as the acid wash was said to be an advanced technique out of scope of the book.

I have pumped the wort on yeast cakes in the past and made good beer.  I am now considering rinsing as another way to improve my brewing practice, and make better beer.

[The Professor]

I've brewed with both simply repitched yeast and with washed yeast. 
Over quite a few batches for comparison, I found no advantage to one procedure over the other so now I just continue what I have been doing for the last 20+years:  I save the cake from the ferment, reptich 1/3 to 1/2 of it into a subsequent brew, and either save the rest for another brew (if it's scheduled to happen within a few days)...or else just dump the remaining 2/3 into the boiling wort. 

That said, if I were taking my repitched yeast beyond my usual 7 or 10 generations, I would consider washing it.  As it stands, I have seen no good reason to go through the trouble or to worry about calculating exactly how much to pitch:  the quantities I've stated have never failed me,  keeping things worry free, and always producing good beer for me. 
After reaching my self imposed re-use limit, I just culture up a new crop and begin the cycle again.

After brewing for so many years and worrying about, trying, and doing  complicated procedures at times,  experimentation revealed in the end that very often the most simplified procedure produces the very same result with less work and less worry and fussing.

I suggest just experimenting to determine what works best for your situation.  And, as b-hoppy pointed out, when in doubt, make a starter.

[jeffy]

"just dump the remaining 2/3 into the boiling wort."

I can't help imagining all of the panicking single cell organisms screaming at the top of their uh membranes as they are dumped into boiling wort like so many live lobsters.
It's a cruel world.

[jibblett]

I've brewed with both simply repitched yeast and with washed yeast. 
Over quite a few batches for comparison, I found no advantage to one procedure over the other so now I just continue what I have been doing for the last 20+years:  I save the cake from the ferment, reptich 1/3 to 1/2 of it into a subsequent brew, and either save the rest for another brew (if it's scheduled to happen within a few days)...or else just dump the remaining 2/3 into the boiling wort. 

prof: why do you add the other 2/3 to the boiling wort?  for the yeast nutrient?

[The Professor]

prof: why do you add the other 2/3 to the boiling wort?  for the yeast nutrient?

precisely.
That tip came many years ago from someone at Fuller's. 
Don't know if it actually helps...but it doesn't hurt!

[beveragebob]

I imagine it would help in a Mead, Braggot or high adjunct beer also. Al did you get my PM?

[richardt]

Anybody have any good tips on yeast washing?  Amounts of pre-boiled water to use?  Types of containers?  How much time is involved?  Are the healthy yeast suspended in solution while the junk settles or does it layer out?  Is chilling the container necessary or just room temp OK? 

[beersk]

Anybody have any good tips on yeast washing?  Amounts of pre-boiled water to use?  Types of containers?  How much time is involved?  Are the healthy yeast suspended in solution while the junk settles or does it layer out?  Is chilling the container necessary or just room temp OK? 

Look it here: http://www.homebrewtalk.com/f163/yeast-washing-illustrated-41768/

[richardt]

Nice link with pictures.  Thanks!