Pitching onto Yeast Cake

[BKBrews]

I've tried to search for this answer, but obviously there are a million topics on this forum relating to yeast and pitching, so it's hard to find.

Is 'Pitching onto a Yeast Cake' literally transferring wort to a fermenter that has just been racked from beer? What are the drawbacks of this?

I have an American IPA in my fermenter since Saturday and was thinking I would rack it to a secondary this coming Saturday, do a new brew, then dump the new wort directly into the primary fermenter from the last beer. Is this how it works?

 

[SBOB]

Pretty much, though the entire yeast cake will likely be over pitching by a pretty decent margin.. (depending on how big the second beer is).

A cup of yeast slurry from the yeast cake is likely a more recommended dose rate

 

[Dan Pratt]

yes that is how it works. you can do it 1 of 2 ways:

1 - make your no chilled wort/beer a couple of days before, rack the existing beer off the yeast into your kegs/bottles/secondary, pour no chilled wort/beer directly into FV that has the yeast cake, close it and fermentation will start within 3-5hrs. (generally aim for a higher gravity beer into the yeast )

2 - rack your existing beer of the yeast cake, add 1ltr of distilled water to FV, swirl and then transfer via outlet to a clean & sanitized container ( flask, jar, container of sorts ) all the yeast you can get out. make your next batch, pitch the yeast.

 

[VP Brewing]

That's basically it. Just make sure you have let the yeast cake come up to within 5°C of the wort you are throwing in onto it.
Although I would only use the whole cake on beers with an OG of 1.080+. Anything under that and it would be a huge over pitch. Probably only need a cup full of slurry for a 1.050 beer.
Pitched a 1.115 RIS onto a wyeast 1728 cake last Wednesday and it was down to 1.036 last night and still ticking over slowly.

 

[MitchD]

Yes that is pitching onto the yeast cake but it is very bad practice. Would you prefer an army of old grannies fat and slow or a crack special forces unit smaller in size but ready for action? The latter is a healthy yeast pitch of appropriate size former is your yeast cake.

What you could do is harvest some of the slurry and repitch an appropriate amount into your next beer, but with this method it is only advised that you work your way upwards in OG ibu and colour. So a repitch from an ipa would only be advisable for say an iipa or barley wine.

 

[VP Brewing]

4 replies in 5 minutes!

 

[mosto]

As others have said, that is the process. It works, but you will generally be over-pitching. Not a massive issue with neutral yeast and a beer requiring a low ester profile. One of the best and most informative articles on AHB about re-using yeast is this one on yeast rinsing. Very simple, very effective.

 

[BKBrews]

Thanks for the quick responses.

I am mainly interested in this method a) for ease (transfer current beer and then immediately pitch new beer) and B) saving myself $10 by not using 2 x new packets of yeast.

My IPA is a 1.062 (down to 1.013) 6.5% beer and I'm planning a Maris Otter/Chinook SMaSH at 1.048 - 1.050 (depending on efficiency). If I just scooped out say 500ml of the slurry and pitched it straight into the new beer would this be effective? What, if any, calculators are out there to determine the ml of slurry required for this method?

Also, is 7 days in primary enough time? I was originally planning to only ferment in primary for 14 days (or until FG) and then bottle directly from the primary.

 

[malt junkie]

As others have said pitching onto a cake is fine but probably an over pitch for a standard beer. However the method is one that is frequently used for high gravity brews, lagers and stuck ferments.

For a standard brew just grab a cup of thee slurry.

 

[Yob]

lots of good threads already, a bit of reading helps

http://aussiehomebrewer.com/topic/44432-re-using-yeast-cake/

http://aussiehomebrewer.com/topic/65013-re-using-the-entire-yeast-cake/

http://aussiehomebrewer.com/topic/85960-reusing-a-yeast-cake/ (Ive use the method a lot more since I posted in there)

and last but not least.. get an understanding of MR Malty

 

[Danscraftbeer]

Trying to keep short. I have done a comparison with an IPA that was all Mosaic hops. Recycled yeast that was a tad under pitched made probably the best beer I have ever made according to a couple of willing guinee pig taste testers. I made the same beer but pitched it onto a full yeast cake second time.
It makes perfectly good beer but this had much less impressive flavour. A bit of science there like about yeast creating flavour when they reproduce but a full yeast cake is massively over pitching and the yeast don't need to reproduce.
So basically largely over pitching robs you of full flavours.

 

[BKBrews]

lots of good threads already, a bit of reading helps

http://aussiehomebrewer.com/topic/44432-re-using-yeast-cake/

http://aussiehomebrewer.com/topic/65013-re-using-the-entire-yeast-cake/

http://aussiehomebrewer.com/topic/85960-reusing-a-yeast-cake/ (Ive use the method a lot more since I posted in there)

and last but not least.. get an understanding of MR Malty

Didn't realise mr malty had the slurry calculator - that's good. If I put everything at the upper limits (thin slurry and up to 25% trub matter) it recommends about 200ml of slurry. That's what I'll do then! Used the grainfather, so there should be very little trub in the fermenter, so will probably just scoop out the 200ml, oxygenate my new wort and throw it in. See how we go!

 

[Danscraftbeer]

Yep, scoop some (sanitary stainless spoon) keep in sanitized mason jar and clean your fermenter! That's much better practice than putting beautifull new wort in with dirty old Krausen muck and dead yeasts etc.

 

[shacked]

+1 for Mr. Malty. I use the thin slurry max trub setting.

 

[Nullnvoid]

This post was really timely. I had an IPA which I bottled on Friday and wanted to put another IPA on the yeast cake. Was just going to dump the lot on the cake as that's what I had done for a big Scottish ale.

But after reading this I went to Mr Malty, worked out how much I needed and away we went. Within a couple of hours the yeast were going bunta!

 

[Danscraftbeer]

Same here. Pitched 400ml scooped W-34/70 into a 40lt IPL at 1.060 last night at Midnight and its hissing away at 5psi now.
The hydrometer sample has a Krausen too.
I take Mr Malty as is, at default setting. Date subjective. Or if you cold crash the yeast cake in a jar you set MrMalty at thickest yeast setting.