What would you do?

[ScottyDoesntKnow]

Whats the best option when it comes to using yeast for brewing 2 small identical batches one after the other?
I normally get 11-12l batches due to equipment restraints and im using M44 yeast for the first time.

Split a 10g pack of M44, rehydrate and pitch for each batch?
Pitch the whole 10g in the first batch, ferment out, bottle, and tip the second batch onto the yeast cake?(I usually gelatin and cold crash)
Pitch the whole 10g in the first batch, ferment out, bottle, wash the yeast and use that for the second batch?
Get another pack of yeast for the second batch?
Something else?

 

[earle]

Whats the OG of your intended brew?

 

[Danscraftbeer]

If your trying for close to identical then yeast count is a factor too weather its dry or recycled.
Eg: half a dry pack for first brew may be under pitched (depends on OG) and then the resultant 2nd brew onto the yeast cake will well and truly be over pitching.
Check yeast counts with a yeast calculator like http://www.mrmalty.com/calc/calc.html

Note package dates of the yeast for its viability as well.

 

[Grott]

Is not just getting another pack of yeast the simplest way? How far off an identical batch are you going to be.? To me you really only get "identical" with the one off batch.

 

[ScottyDoesntKnow]

Identical in the sense of same amount of grain and hops, same mash time and temp etc. obviously there will be subtle differences between batches.
OG is 1.046, I normally use a 10g pack of US-05 for a 12l batch and feel I may be over pitching as a packet is usually recommended for 23l batch.

 

[S.E]

Whats the best option when it comes to using yeast for brewing 2 small identical batches one after the other?
I normally get 11-12l batches due to equipment restraints and im using M44 yeast for the first time.

Split a 10g pack of M44, rehydrate and pitch for each batch?
Pitch the whole 10g in the first batch, ferment out, bottle, and tip the second batch onto the yeast cake?(I usually gelatin and cold crash)
Pitch the whole 10g in the first batch, ferment out, bottle, wash the yeast and use that for the second batch?
Get another pack of yeast for the second batch?
Something else?

[SIZE=11pt]If you are doing one batch immediately after the other the easiest (apart from the tipping on the yeast cake) and probably best option would be take about a cup full of yeast from the first batch and pitch it in the second without the yeast washing into a clean fermenter. [/SIZE]

 

[Danscraftbeer]

If you do the calculations properly you may be surprised that 1 full packet is closer to pitch count for 12lt.
What your doing is also a good opportunity to test this theory of yeast count.
Pitch the first brew with 1 packet of yeast and then pitch the second brew onto the yeast cake and then do a taste comparison of the end results.

Under pitching (half the packet) can get different flavours you may or may not like as well to take into consideration.

Sorry, cant make it simpler rather than making it more complicated ha..

 

[Inconceivable]

Like Dan says go check a pitch calculator to see how many grams of dry yeast you'll need .

Always rehydrate for sure.

If it was me and the calc said I couldn't just split the pack and I needed more cells I'd either buy a second pack of yeast or grow up a starter from the first pack to give me my target cell count for both batches. I have no qualms in using dry to make a starter

 

[S.E]

[SIZE=11pt]If you are doing one batch immediately after the other the easiest (apart from the tipping on the yeast cake) and probably best option would be take about a cup full of yeast from the first batch and pitch it in the second without the yeast washing into a clean fermenter. [/SIZE]

Sorry don’t know what I was thinking, I completely missed the 11-12l batches bit. What I should have said was I normally pitch a cup full of yeast in 55l.

 

[ScottyDoesntKnow]

Thanks for all the replies and advice, using the calculator dan linked it's 6g of dry yeast per 12l batch so a 10g pack of yeast would go close to doing both batches.
I like the idea of pitching the second batch straight onto the yeast cake, as you pointed out it will be a good opportunity to see if I can taste any difference.
The problem with that is it will probably be a huge over pitch for the second batch which from what ive read can cause unwanted flavours just as under pitching.
The Mr. Malty calculator suggests i'd only need 50mls of slurry for the second 12l batch so maybe that's the best option.

Another question came to mind when I was thinking about this, If you were to pitch on the entire yeast cake, hop trub and all - how much will that hop matter affect the next batch? For example this particular beer has a dry hop of 3g/l.
And if you add gelatin to the primary fermenter, cold crash, bottle and then add the next batch onto that yeast cake in the same fermenter, how much gelatin would hang around for the second batch?

Cheers

 

[Coodgee]

Most brewers will regard a fresh yeast slurry from a batch of beer as sludgy gold. It's a huge amount of yeast - viable and ready to go - at your fingertips. I would pitch the right amount according to the yeast calculator for the first batch and then do the same with the yeast slurry for the second batch. Only pitch the correct amount.

 

[Lionman]

I have started reusing yeast and the results have been great.

What I have been doing is draining the slurry through the tap.

After filling the keg and a couple of bottles with the dregs, I drain the runny leftovers and ditch them. When the yeast starts coming out nice and thick, I capture it in a sanitised container. The amount I capture depends on the OG of the next brew.

I find that when it settles a very thin film of beer will remain on top. This allows me to refrigerate it for a week or so with no worries. Personally, I don't think it's worth washing it, though I wouldn't pour slurry from an IPA into a summer ale.

I found a calculator for the repitching of the slurry. It's not that accurate (because you have to guestimate the cell count without a microscope) but seems to do the trick.

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

 

[ScottyDoesntKnow]

Hey all, I captured about 500mls of slurry from the bottom of the fermenter after bottling the first brew. Let that sit and decanted every other than the trub at the bottom into 2 400ml mason jars. I've had those in the fridge for 5 days and I'm ready to pitch in the next brew. Question is what am I looking at as yeast slurry? Using mr malty calculator, when it refers to the yeast slurry, is it referring to the small white layer on the bottom of my photo?

 

[Lionman]

Yes, the yeast falls out of suspension and settles to the bottom.

You collected 500ml and that is what you have? Are you sure you didn't collect 500ml of beer dregs?



This is what I got after collecting about 300ml of slurry and washing it a few times. This is my third generation of WLP090.

 

[Grott]

Yes, the yeast falls out of suspension and settles to the bottom.

received_10208625594346726.jpeg

I may be wrong but I thought the yeast settled in the middle position ie. sediment at the bottom, yeast then liquid/water on top if washed?

 

[Lionman]

I may be wrong but I thought the yeast settled in the middle position ie. sediment at the bottom, yeast then liquid/water on top if washed?

In my collections, there is no discernable difference in the slurry at the bottom. It looks very uniform to me. I do however keep my fermenter as free from debris as possible.

I'm sure there is a fair proportion of dead/non-viable cells and a small amount of kettle trub, but these become nutrients for the living cells when they are pitched into the wort.