Pitching onto yeast cake - how?

[nztayls]

Gidday all,

So I am brewing my first sour beer at present - a Flanders Red that I am using WhiteLabs WLP665 Belgian Sour Mix 1. I have read elsewhere that after racking to secondary it is possible to pitch wort straight onto the yeast cake at the bottom of the original fermentor. Is it is simple as that?, or is there anything else you need to do (apart from the obvious - such as sanitation etc).

Any advice would be greatly appreciated!

 

[Calder]

It is that simple. A couple of cautions:

- If the cake is only a few weeks old, you probably want to take about 3/4 of the cake away. The sacc yeast will be dominant and tear thru any fresh wort.

- If the cake is a few months old, you should be prepared to pitch some fresh sacc if no active fermentation is seen within a few days. The bugs do well in low PH environments, but sacc doesn't, so there might not be much of it remaining.

I think you will get better results in both beers if you leave the first one on the cake for several months before racking to secondary.

 

[nztayls]

Great, thanks!

 

[MaddBaggins]

What Calder said.

I dumped a porter onto a cake I had just racked off...once. Within about 2 hours it blew the lid clean off and foamed all over the place. There is such a thing as overpitching.

 

[nztayls]

It is that simple. A couple of cautions:

- If the cake is only a few weeks old, you probably want to take about 3/4 of the cake away. The sacc yeast will be dominant and tear thru any fresh wort.

I wish I had taken this advice.....

 

[nztayls]

Okay, so I should have listened to the sage advice about dumping 2/3 of the yeast cake. I figured I was going to have plenty of headspace, so I would risk it. Bad move. I have attached a blow off tube now, but am having to clear it every few hours, as I don't have any real wide tubing. So, a couple of questions:

1. Is there any harm in removing a portion of the kraussen from the top of the fermentor to create some more space?

2. And can the yeast slurry be washed and saved for future use like a normal yeast? (noting that this is a Sour Mix, so contains bugs as well as sacc and brett)

Its not all bad though, the first batch of flanders red that I racked into secondary is looking pretty good! - now I just need to wait a year of so to see if it is any good.

 

[Calder]

1. Is there any harm in removing a portion of the kraussen from the top of the fermentor to create some more space?

You can probably do that. I'd just leave it. It should be settling down.

2. And can the yeast slurry be washed and saved for future use like a normal yeast? (noting that this is a Sour Mix, so contains bugs as well as sacc and brett).

Don't wash it. You will probably wash a lot of the bugs away. Best way to keep it is under beer. Once active fermentation is slowing (not stopped), rack to secondary and discard the cake. Then when you want to re-use this bug mix, rack again, and you will have fresh cake filled with bugs. Use this beer to store the bugs. If the cake is over 6 months old when you come to use it, the sacc yeast may be dead, and you might have to pitch fresh yeast with it.

 

[mbbransc]

Don't wash it. You will probably wash a lot of the bugs away. Best way to keep it is under beer. Once active fermentation is slowing (not stopped), rack to secondary and discard the cake. Then when you want to re-use this bug mix, rack again, and you will have fresh cake filled with bugs. Use this beer to store the bugs. If the cake is over 6 months old when you come to use it, the sacc yeast may be dead, and you might have to pitch fresh yeast with it.

Is the idea behind this that most of the cake after 1-2 wks will be sacch only? So if you use a secondary's cake a month later you'll be more likely to have a similar mix ratio as the original? Or at least, it won't be supremely overrun with the sacch strain?

I'm planning on starting a monthly pipeline where I was going to rack the sour to secondary and pitch new wort on 1/3 remaining yeast cake. Are you suggesting for this I'd still be better off racking to secondary after 1-2 weeks, and then to tertiary a few weeks later? And then using whatever cake remains in the secondary for the new brew?

thx

 

[Calder]

Is the idea behind this that most of the cake after 1-2 wks will be sacch only? So if you use a secondary's cake a month later you'll be more likely to have a similar mix ratio as the original? Or at least, it won't be supremely overrun with the sacch strain?

I'm planning on starting a monthly pipeline where I was going to rack the sour to secondary and pitch new wort on 1/3 remaining yeast cake. Are you suggesting for this I'd still be better off racking to secondary after 1-2 weeks, and then to tertiary a few weeks later? And then using whatever cake remains in the secondary for the new brew?

thx

Go with your first thought. I assumed you were planning on saving the mix for a while. Still, don't wash.

 

[DurtyChemist]

I would keep the beer on your sour mix until it has a sour level you want THEN take slurry and use it for more pitches. Sort of a Rosalare type mentality. I pitched my 655 on a Berliner Weiss and the pH isn't even below 4.5 yet and it's sittting at 68F. I think you need to let the sour beer age much longer instead of moving it off the bacteria before it forms a pelicle.

 

[finsfan]

I would keep the beer on your sour mix until it has a sour level you want THEN take slurry and use it for more pitches. Sort of a Rosalare type mentality. I pitched my 655 on a Berliner Weiss and the pH isn't even below 4.5 yet and it's sittting at 68F. I think you need to let the sour beer age much longer instead of moving it off the bacteria before it forms a pelicle.

forming a pellicle has nothing to do with the level of acidity, funk, or complexity. Pellicles are formed when oxygen is present in the head space of a fermentor or carboy, not when it is sour. Having a pellicle is also not always a gaurantee even if there is oxygen, sometimes you just wont have one.

 

[mbbransc]

I would keep the beer on your sour mix until it has a sour level you want THEN take slurry and use it for more pitches. Sort of a Rosalare type mentality. I pitched my 655 on a Berliner Weiss and the pH isn't even below 4.5 yet and it's sittting at 68F. I think you need to let the sour beer age much longer instead of moving it off the bacteria before it forms a pelicle.

I think when I rack it to secondary enough bugs will transfer with it. Maybe I'll purposely pick up some of the yeast cake too since I only need ~1/3 of it for the fresh batch.