Anyone ever put new wort in just drained fermentor?

[Dland]

I kegged off conical today, the residue below the upper valve is still there, and working a little. I did two trub dumps, so most of the solids are already gone.

The small remainder above bottom valve is still working a bit, and airlock tube still in place after CO2 displaced closed transfer. This is normal now that I rack to kegs for spunding instead of after complete fermentation.

I had the lazy idea of just pumping new wort in soon, not lugging fermentor up stairs for cleaning etc, running the same yeast.

Fermentor was fully sanitized before fill last week.

Would be hoping the yeast in bottom of fermentor would be good to go with a little O2. Some risk if any other critter that got in there would get a foot hold, I know, but it is a saison yeast, so it would have some competition.

 

[Gnomebrewer]

It's not uncommon - putting a new beer on an existing yeast cake. I'd suggest dumping 3/4 of the yeast though - a full cake is overpitching. There's very little risk of contamination if your sanitation practices were good and you used a closed transfer. In fact, I'd think you'd be at more risk by tipping yeast into a santised container, washing/sanitising your fermenter, then putting wort and yeast back into the fermenter than you would by simply dumping wort onto existing yeast cake. Just my opinion though.

Edit: I just realised you've already dumped 'trub' - is that trub+yeast, or just what was below the yeast?

 

[Dland]

Edit: I just realised you've already dumped 'trub' - is that trub+yeast, or just what was below the yeast?

Using the word trub loosely perhaps, very little hot break went into fermentor initially. Yeast residue after most of active fermentation, stuff dropped out by finings, some hot break no doubt, not much.

I should measure the volume below the top discharge valve and the dump valve, but I'll guess it is over a pint of the yeasty trailings, which are still working.

 

[Steveruch]

I'd do it if I were following a 1.040 bitter with a 1.090 barleywine

 

[Gnomebrewer]

For a 5 gal batch, you'd want about a quarter of that.

 

[Bubbles2]

I pull and re-use. I also use some of that pull on the next batch at 15 min left to the boil, yeast food. Aforementioned, you do not want to go dark to light brew. You don't want to go Porter to Pilsner style, rather vice verse.

 

[Dland]

I was just thinking of running another basic ale, mabey heavier on adjuncts this time, 50% pils, 25% 2 row(probably Irish Malting stout base) 12.5 rye malt, 12.5 white wheat malt.

Finish batch usually 10 or 11 gallons.

I'm not so much into yeast cultivation, maybe later for that. The idea of "hot bunking" the fermentor and not having to bring up from cellar to clean and sanitize for a batch or two is intriguing.

 

[Gnomebrewer]

How soon are you adding the fresh wort?

 

[Dland]

Thinking I'll brew today, so it will be in there this afternoon. I racked off the last brew from a conical yesterday. This is probably not a revolutionary concept, just revolutionary to me because it never occurred to me before. Probably done in some form in commercial brewing too.

Better get going if I'm going to brew before the thunderstorms hit.

 

[Soulshine2]

I kegged off conical today, the residue below the upper valve is still there, and working a little. I did two trub dumps, so most of the solids are already gone.

The small remainder above bottom valve is still working a bit, and airlock tube still in place after CO2 displaced closed transfer. This is normal now that I rack to kegs for spunding instead of after complete fermentation.

I had the lazy idea of just pumping new wort in soon, not lugging fermentor up stairs for cleaning etc, running the same yeast.

Fermentor was fully sanitized before fill last week.

Would be hoping the yeast in bottom of fermentor would be good to go with a little O2. Some risk if any other critter that got in there would get a foot hold, I know, but it is a saison yeast, so it would have some competition.

do it. dont forget the blow off tube

 

[Dland]

For a 5 gal batch, you'd want about a quarter of that.

I take it to avoid overpitching. Short of microscopes and yeast counts, is there a rule of thumb for volume of active "bottom krausen" per gallon wort?

I've mashed in already, but could still drain some more off bottom of fermentor. My guess is there may be close to a quart in there, as there is a tri clamp 90% fitting before valve.

When I've done standard krausen transfer from one fermentor to another, it is usually just what is on the top of solids after fresh trub dump, less than a pint probably.

From what I've seen of this yeast, it does not take much. Took right off last week, 11.5 grams dry pitched in 10 gallons.

 

[yowzers]

Yes you're fine if you've removed most of the yeast. I do it quite frequently.

 

[millsbrew]

I pitch on to yeast cakes for my sours regularly. I don’t bother with removing any of the yeast. I use the full cake to get a dry second batch for blending. It is not “bad”, just really dry, which I like in my sours. Also, just give it a shake, not pure O2 unless you have a serious blowoff setup.

 

[Gnomebrewer]

is there a rule of thumb for volume of active "bottom krausen" per gallon wort?

Mr Malty calculator has a 'yeast slurry' option. For a 10 gal batch of 1.050 Ale, it says about third of a cup to a cup of slurry (depending on the thickness and non-yeast percentage).
The general rule (that I've heard) is a quarter of the yeast cake for a new batch the same size and gravity, although I suspect that might still be a bit of an overpitch. As it's still active, I'd lean towards a smaller pitch (maybe 1/2 cup) and a good hit of O2.

 

[Dland]

I take those calculators with a grain of salt, but sounds like might be general guide line.

The brew was pitched at 1:30 today and is already working.

Not having to lug a fermentor up & sanitize I almost feel like I got away with something, like playing hooky from school..haha