How much yeast for priming aged beer?

I would aim for "just right". You want 1 million cells of active yeast per ml of beer, so 13L would require 13 billion cells. If you have 100% viable yeast that's ~6 - 7 ml of liquid yeast slurry.

I have successfully added more of the same yeast to an aged-beer to accomplish what you are trying to do. It may be easier to add CBC-1 (conditioning yeast). It comes in a 11g packet but that's enough for 100L, so you'll measure out just what you need. I've never been able to save the rest (majority of packet), so it's a mite expensive for what you get . . . but it does work. Most homebrew stores carry it, here's the details:
https://www.lallemandbrewing.com/docs/products/tds/TDS_LALBREW_PREM_CBC1_ENGLISH_DIGITAL.pdf

 

CBC FTW

 

I once used a whole sachet (11.5 grams) of dry yeast when bottling a batch of Quad. Those beers turned out just fine. Maybe you don't require a whole sachet but I suffered no ill effects from pitching the whole thing. You likely only need a portion but what will you do with the remaining yeast? Likely just throw it away? Why not pitch the whole thing?

Cheers!

 

You need very very little. Just a couple grams or 1/4 pack is just fine.

 

I have had good results with a quarter pack of dry yeast. Although I haven't used it, as I have done little priming for several years, the CBC yeast seems like an ideal candidate.

 

Problem solved.The solution always seems to be "make more beer."

 

Then you could add a portion of that sachet for bottling and the rest for the other beer (will there be enough for the other beer?).

I am uncertain what you mean by "eaten up". During bottle conditioning the yeast conduct a secondary fermentation. As I mentioned above when I used a whole sachet when bottling my Quad there was no issues with that batch.

Cheers!

 

The yeast will only eat what's available to them. Once the food source is gone, the yeast that didn't get their fill will die or go dormant.

If using more yeast than was needed to complete the 'secondary fermentation', it seems like there would be more sediment than normal in the bottles. Was that not the case?

 

Not that I could determine by just 'eye balling' things.

If there was an additional 1/16th of an inch of sediment would you consider that an issue?

Cheers!

 

1/16” probably not…..but 5/64”? Now that's where I draw the line.

Jack, there was no subtext to suggest the beer had an issue. My interest was in adding another data point to my expanding knowledgebase. Thank you for helping with that.

 

As I posted already (with emphasis in bold this time):

"I once used a whole sachet (11.5 grams) of dry yeast when bottling a batch of Quad. Those beers turned out just fine."

To respond to the specific question: there was zero "raw yeast flavor".

Cheers!

 

I believe you when you say no raw yeast flavor. What about cooked yeast?
Joking.

I did once use an entire dry yeast packet just prior to priming and had more yeast sediment than usual in the bottled beer, but I suspect this was coincidental. I probably did not rack cleanly from the fermenter to the bottle bucket and picked up yeast sediment in the fermenter.

FWIW, I think it is probably rare that adding yeast at bottling is necessary, based on the times I didn’t and everything turned out ok. But I understand the security it can bring when one has invested time and ingredients to make a quad or other big and/or aged beer.

 

So, I have only made two batches of Quad (so far) and the second batch I just completely forgot to add yeast at bottling. I did 'remember' that I forgot a week or so after bottling and I must confess I was concerned about this batch. It took a long time for this beer to reach full carbonation (which is generally true for all of my higher gravity batches) but this batch turned out just fine as well.

I would suggest that adding some yeast at bottling for higher gravity beers (or aged beers) is within the context of insurance. It may well be that yeast added at bottling is not needed (e.g., my second batch of Quad) but from my perspective it does not hurt and if your yeast from a particular batch is stressed/tired if may be that it was needed.

In the big scheme of things a sachet of dry yeast is cheap. Why not take the step here?

Cheers!

 

Once again, the tiniest organism provides a metaphor of life.

 

Not disagreeing. RDWHAHB. And when you can take easy measures to help you worry a little less and relax a little more, where's the harm?

 

Jamil recommends re-yeasting with 1/10 the original pitch.