Rack onto previous yeast cake, but also with 4 oz. previous hops?

[sibelman]

I've had fine success in the past, racking a DIPA onto the yeast cake left after I moved an IPA to its serving keg. (Dry hopped in the serving keg.) I was going to do that again, but there's a twist.

This time around, I added 4 oz. of pellet hops to the IPA in the fermenter (Flex+ bucket), and they'd still be in there after I move the IPA to its serving keg. The DIPA would doubtless ferment fine, but what about that tired Mosaic hop sludge? Maybe that's a crazy idea, hence this post.

I'm planning to dry hop the DIPA with Mosaic too, either in the fermenter or the serving keg - maybe both! Should I make a fresh starter instead? Wash the existing yeast/hop cake (if that's even possible)? What do y'all think?

 

[lumpher]

You could rack it straight over, but in the case of a lot of hop sludge, I prefer to rinse my yeast. A couple cycles of rinse and pour off should give you some decently clean yeast and only take a few minutes.

 

[sibelman]

cycles of rinse and pour off

Thanks, @lumpher. So, pour in some boiled, cooled water, swirl, pour off (hopefully more hops than yeast) and repeat?

 

[An Ankoù]

I'm planning to dry hop the DIPA with Mosaic too, either in the fermenter or the serving keg - maybe both! Should I make a fresh starter instead? Wash the existing yeast/hop cake (if that's even possible)? What do y'all think?

What are you hoping to gain by that?

 

[sibelman]

The purpose is to reuse the giant supply of yeast that would otherwise be discarded, saving money and giving the higher gravity second batch a really healthy start. A win-win, complicated by the dry hops.

Clear?

 

[lumpher]

Thanks, @lumpher. So, pour in some boiled, cooled water, swirl, pour off (hopefully more hops than yeast) and repeat?

Yep. When it settles, you'll have distinct layers. Since trub settles faster than yeast, the bottom layer will be dark sludge. The layer above that should be white yeast. Pour in the water, swirl it pretty good, and let it settle. Pour off that water, then carefully pour off as much of the yeast as you can into another container. Lather, rinse, repeat. You should have a large part of the yeast by then. The more times you rinse and the longer you let it settle, the better it will be, but I'd trade that off to only do it twice, especially considering you're going from IPA to 2x IPA and not Pale Ale to Imperial Stout or some such big difference.

 

[mashdar]

If it were me I'd give it a try, hops and all. The biggest issue may be hop creep from the get-go, but if it's an all-malt DIPA that could make it a little drier?

 

[lumpher]

If it were me I'd give it a try, hops and all. The biggest issue may be hop creep from the get-go, but if it's an all-malt DIPA that could make it a little drier?

Yep, that's what I was thinking when I mentioned he could just rack onto it, but with 4 oz, could be substantial hop-creep. Either way it's an option to consider.

 

[TBA]

This thread might be of help in your decision https://www.homebrewtalk.com/threads/hop-reconstitution.731400/#post-10348605

 

[mashdar]

A lot of opinions here and on the internet, but I haven't heard anyone say they've tried it. I'm skeptical that hops can be fine in one beer but ruin the next one. I'd wager it's a detectable difference, but not whether it makes worse beer*.

References to marmite are odd; marmite is yeast, so is the argument against re-using a yeast cake at all?

I'll try anything once : ) But I guess it's a cost/risk-mitigation question. I doubt it'd be a dumper, but might not be the beer you were hoping for. Is it worth it to save some effort rinsing yeast, and provide the community with anecdata?

*If you prefer hazies that only have the fruit punch orange juice flavor with no noble character, then maybe it would be worse.

 

[Dland]

It will probably be OK, but would probably be better if you can find a way to leave the dead yeast solids, trub and old hops behind. The solids don't add anything positive to your beer or the process.

I re use yeast left in fermentor all the time, but have the benefit of a bottom dump in my conical to remove the thick bottom sludge, I'm assuming OP does not have that luxury. But if you can find a way to skim, pour or siphon off some of the more liquid slurry on top residue after racking, clean fermentor then add back slurry with now wort, that should also work. You don't need that much if yeast cake is from a recently fermented batch, there will plenty of live yeast in a ounce or two of fresh slurry.

Another approach is to just add a cup or pint of beer from near bottom of fermentor to your new wort, that will have the same result.

 

[sibelman]

So, out of laziness-- and total inexperience with washing yeast -- I went with just racking onto the residue of the previous beer. I was also anxious about sanitation: possibly introducing some nasties while prepping the yeast for re-use. Maybe next time I'll be more brave.

I'll let y'all know how it turns out in a few weeks. Thanks for all the helpful responses.

 

[crazyjake19]

My personal opinion - I never rack directly onto a yeast cake in a fermenter. Unless the first beer was a small batch, reusing the entire yeast cake would be a gross overpitch. It doesn't take long to pour the yeast in a jar, clean and sanitize the fermenter, and then refill it. Then pitch the correct amount of yeast.

 

[sibelman]

gross overpitch

correct amount

@crazyjake19 , how much is the correct amount for, say, a five gallon batch with an OG of 1.065?

 

[sibelman]

Results are in: it worked fine to rack onto the hoppy IPA yeast cake. Fermentation started fast, but the increased attenuation I hoped for did not occur.

Dry hop character (commando in serving keg) is weak. Much as with previous batches of this DIPA. Apparently, this style requires large amounts of dry hops.

All in all, kinda boring. But it saved me $12.

 

[mac_1103]

Dry hop character (commando in serving keg) is weak. Much as with previous batches of this DIPA. Apparently, this style requires large amounts of dry hops.

I'm a little disappointed in the dry hop character in my Imperial IPA. Four ounces in a five gallon batch. Guess I need to stop being so cheap since I've got a freezer full of hops after all.

 

[sibelman]

disappointed in the dry hop character in my Imperial IPA.

More hops should help. I keep thinking of method changes, not just out of cheapness:

1. pre-grinding the pellets (okay for serving keg with floating dip tube, maybe not so good in a hop dropper into the fermenter?)
2. "rousing" (could be just swirling the vessel)
3. recirculating (feasible in my accessorized Spike Flex+, but sounds like a major PITA).