The Age of Slurry or Trub

[Journeyman]

Recently I decided to try just dropping the next brews on top of the trub from the ones I'd just kegged. Long story short, life got in the way and I didn't get to it for 6 days. All that time the 2 x RV's were in the ferment fridge at 2° although I had tipped off the remaining beer, so there was O2 in there.

I wasn't worried about the O2 because I figured the new brew would eat it up.

Came time for the next brews I chickened out and cleaned out the FV's. They smelled fine and stirring the trub showed smooth custardy consistency and no sign of anything awry, but I can't afford to chuck brews.

So I'm curious - do you think they would have been OK or was I right to sink them?

[Greenyinthewestofsydney]

You would probably find it would ok as the temp would inhibit the growth of anything. But I wouldn't risk it.

If it was at room temp then almost certainly you would get acetobacter growing and eating the remaining ethanol in the presence of the oxygen. I have left a fermenter for a week at room temp when I had to go away unexpectedly and the vinegar and nail polish smell of acetobacter was overpowering. That won't grow at 2c though and I can't think of another organism that would work at 2c that would eat the ethanol. 

But once again. I wouldn't have risked it either

[iBooz2]

If / when I do a dirty batch and if I do not know if I will get enough time to do the whole process in one go i.e. keg, bottle and drop in fresh wort, then I leave the bottle part until the next day.  That way there is plenty of beer sitting over the trub, CO2 pretty much undisturbed and I keep the FV say just overnight or max 48 hours at the cold crash temps and have gotten away with it each time.  Note I only do one dirty batch then the very next time its a complete strip down, thorough clean and soak in SP and then start over fresh as.

I do not do many dirty batches but thinking back it would be about six in the last few months and its worked out every time.  Note they are usually exactly the same brew or recipe in that same FV when really pressed for time.

Edited July 15, 2021 by iBooz2

[Worthog]

Just twirl the dregs of tbe fermenter tub, after keg/bottle, Fill a pet bottle from the fermenter tap. Cap it and put it in the fridge.

When you next wish to yeast a brew, pour off some beer on top of the pet sediment, twirl it slightly, because the best yeast is that soft layer you can see in the pet. Then pour 200ml of slurry into your wort.

I keg "WortHog Brewery" pale ales for several people who love my 3 recipe ales.

So the yeast slurry idea works well. I limit it to 3 generations.

Cheers

[iBooz2]

5 minutes ago, Worthog said:

Just twirl the dregs of tbe fermenter tub, after keg/bottle, Fill a pet bottle from the fermenter tap. Cap it and put it in the fridge.

Yes WH I think we nearly all do that.  I have an array of 1 L and 500 ml reagent jars with a collection of fresh yeasts.

What we are talking about here is, I think, doing a dirty batch to save the time rinsing, cleaning and sanitising of the FV so you can pump out another quick batch of the same beer.

I agree about your technique and limiting the re-use of slurry.  When my yeast bank gets used a few times I usually use a starter if time permits or just dump the old one down the sink and start fresh with a new pack of yeast.  I read of many who have used the same ones over and over without any detrimental effect so I know that works for them.  Trouble with my collection is that the yeast gets too old before I need that strain again hence a starter or fresh packs.  Always have plans of brewing that same brew again soon but there are just too many recipes to try and storing slurry becomes a bit counter-productive in my brewery.

[Malter White]

King Ruddager did a Fast Homebrew video on YouTube of a "dirty brew" as you call it. I don't remember the details but it could be of interest to you.

I've found the easiest way to save yeast is to retrieve it from the sediment of my bottles after drinking and I believe it's more sanitary. My process:

1. Drink beer.

2. Replace lid and return to fridge.

3. Drink more beer. 

4. Leave enough beer in bottle to swirl up sediment, say 50ml, and transfer to the first bottle. Put back in fridge.

5. Repeat this until you have enough yeast. I usually do about 3-4 long necks.

6. Then reactivate the yeast as per the Coopers video method in a sanitised soft drink bottle.

Naturally this is harder to do if you don't bottle your beer. If you only keg your beer my advice is to only follow steps 1 and 3.

 

Edited July 15, 2021 by MUZZY

[Journeyman]

1 hour ago, MUZZY said:

I've found the easiest way to save yeast is to retrieve it from the sediment of my bottles after drinking and I believe it's more sanitary. My process:

1. Drink beer.

2. Replace lid and return to fridge.

3. Drink more beer. 

4. Leave enough beer in bottle to swirl up sediment, say 50ml, and transfer to the first bottle. Put back in fridge.

5. Repeat this until you have enough yeast. I usually do about 3-4 long necks.

Naturally this is harder to do if you don't bottle your beer. If you only keg your beer my advice is to only follow steps 1 and 3.

 

So... Drink keg, leave in fridge. Drink more keg and tip remains into 1st keg.

Would 3 or 4 kegs be enough do you think?

11 hours ago, Worthog said:

Just twirl the dregs of tbe fermenter tub, after keg/bottle, Fill a pet bottle from the fermenter tap. Cap it and put it in the fridge

That means I have to go and drink soft drinks to get the bottles. 

Hmm... although I do have a few PET's left over from bottling days - they would do with a label to ID which brew it is from. Be a bit hard to see the 'soft layer' though - is it on top of the sediment?

[Malter White]

1 hour ago, Journeyman said:

So... Drink keg, leave in fridge. Drink more keg and tip remains into 1st keg.

Would 3 or 4 kegs be enough do you think?

You're not very good at following instructions!
1. Drink beer.
3. Drink more beer. 
I don't think I can make it any simpler than that. 

[BlackSands]

12 hours ago, iBooz2 said:

What we are talking about here is, I think, doing a dirty batch to save the time rinsing, cleaning and sanitising of the FV so you can pump out another quick batch of the same beer.

I've tried this approach a few times sucessfully, the only diiference being that I scooped out some of the yeast cake to minmise any possible negative effects of what is essentially a substantial over-pitch.  I didn't worry too much about whether the beer that followed was "compatible" with the one before either,  i.e. I've thrown a fresh light-coloured wort onto a partial cake that had just fermented a darker style and also onto cakes of heavily hopped beers.  It doesn't appear to have caused any problems.   

[Worts and all]

52 minutes ago, MUZZY said:

You're not very good at following instructions!
1. Drink beer.
3. Drink more beer. 
I don't think I can make it any simpler than that. 

I tried your method. I sink the fourth bottle down the pour ,put into frig, -wait a minute- - why are all these bottles in the frig?? Some still full. Out they come, no room! Have to drink. Might get warm. What’s going on. I don’t use old yeast. New packet on can! Ah well, drink rest of bottles everything will be lovely. Everything lovely already. These people must be crazy. Everybody crazy ‘cept you and me. Not sure about you. Cheers!

[Journeyman]

So, back to the question... Is it enough to trust my nose on such things given the original scenario?

I have a good nose. I use it for red wine and lotsa stuff. To the extent I don't worry about use-by dates if my nose says it's OK. So if the trub smells OK after several days it should be OK... right?

[Shamus O'Sean]

Yes

[Tricky Micky]

42 minutes ago, Journeyman said:

So, back to the question... Is it enough to trust my nose on such things given the original scenario?

I have a good nose. I use it for red wine and lotsa stuff. To the extent I don't worry about use-by dates if my nose says it's OK. So if the trub smells OK after several days it should be OK... right?

Trust the Snozz!

[BlackSands]

2 hours ago, Journeyman said:

So, back to the question... Is it enough to trust my nose on such things given the original scenario?

I have a good nose. I use it for red wine and lotsa stuff. To the extent I don't worry about use-by dates if my nose says it's OK. So if the trub smells OK after several days it should be OK... right?

Thresholds of perception vs thresholds of contamination....   ?

[Journeyman]

15 minutes ago, BlackSands said:

Thresholds of perception vs thresholds of contamination....   ?

Haha! True dat.

But my threshold of contamination has been exceeded only once I can recall - an Indian curry chicken that gave me the only food poisoning I'd ever had.