adding yeast at bottling time

I've heard that sometimes people add yeast at bottling time when the beer has been conditioning a long time in the secondary. My question's more hypothetical than practical, I suppose; I have a belgian blonde that's been in the secondary for about 1 month. It is super clear...and I'm thinking of leaving it for another month. Would that be long enough to require more yeast?

Whaddaya think? And has anyone done this before?

I'd say you should add more yeast. There will still be some yeast left, but the carbonation may become less predictable and may take a very long time.

Kai

I have also done this before and was impressed by the fast carbonation. The yeast sediment was comparable to conventionally primed batches.

The procedure I've seen and recently tried was to pitch another batch of yeast 3 days before bottling. I guess this allows the yeast to get 'acclimated' before getting hit with priming sugar, but don't really know.

So if I pitch another batch of yeast a few days prior, I suppose I should bring the belgian back to room temp...right?

What about yeast strain? At first I thought I should use the same strain (abbey ale yeast), but then I started to think: maybe I could use a neutral, clean fermenting strain like US 56, since it is only there to convert the corn sugar, anyway (and it would save me a about $5).

When I did it, I pretty much made a starter and added most of it (a measured amout w/o the yeast sediment) to the bottling bucket. I only wanted to have the yeast that is still active and in suspension.

But if you just want to prime with a concentrated corn sugar syrup, you can add the yeast at bottling time or 3 days prior as the Baron suggests. And yes, I would bing it back to fermentation temps before adding the yeast.

Kai

I have had good results adding a packet of US 56 three days before bottling.

- magno

magno said:

I have had good results adding a packet of US 56 three days before bottling.

- magno

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Do you rehydrate it or anything? When I use the 56 for primary, I just sprinkle it on and it goes to work. That would be really convenient.

My $0.02..

I added a small starter of yeast to some brews I had sitting for about 2 months before bottling. The beers carbonated fine, but I did get diacetyl in the bottles and I had to wait for it to go away, which took a few weeks. Basically, the beer was carbonated at 2 weeks, but tasted like butter until abot 4 weeks.

-walker

Walker-san said:

My $0.02..

I added a small starter of yeast to some brews I had sitting for about 2 months before bottling. The beers carbonated fine, but I did get diacetyl in the bottles and I had to wait for it to go away, which took a few weeks. Basically, the beer was carbonated at 2 weeks, but tasted like butter until abot 4 weeks.

-walker

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Well, I suppose that's better than the beer being flat. Plus, I shouldn't be drinking it before 3 or four weeks pass anyway (of course, I will but that's neither here nor there...)

Monk said:

Do you rehydrate it or anything? When I use the 56 for primary, I just sprinkle it on and it goes to work. That would be really convenient.

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I've been making small (~1 pint) starters for the US 56, but I have been told that it is unnecessary.

- magno

Walker-san said:

I added a small starter of yeast to some brews I had sitting for about 2 months before bottling. The beers carbonated fine, but I did get diacetyl in the bottles and I had to wait for it to go away, which took a few weeks.

Click to expand...

I have to watch out for this next time I prime with Krauesen. I did this twice already (BTW, the Pale Ale I gave you was pimed with Krauesen) and didn't notice any diacetyl. But I can see this happening with this method. What strain of yeast was that?

Kai

magno said:

I've been making small (~1 pint) starters for the US 56, but I have been told that it is unnecessary.

- magno

Click to expand...

Starters with extract, or just rehydrating with water? Based on what I've read, I agree that you don't need a starter with dry yeast (already has quite high cellcount), but I don't think rehydrating it in a little water is a bad idea. Apparently that prepares it for the osmotic pressures of being dropped in wort which can actually crush and destroy some of the yeast cells.

I make the starter with .25 cup DME.. probably overkill

... I don't think rehydrating it in a little water is a bad idea. Apparently that prepares it for the osmotic pressures of being dropped in wort which can actually crush and destroy some of the yeast cells.

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Are you saying that the physical fall from the packet to the wort will actually rupture the cell walls? Amazing...

- magno

magno said:

Are you saying that the physical fall from the pasket to the wort will actually rupture the cell walls? Amazing...

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Not that...the yeast is dry so it wants to absorb wort (which has a much higher gravity than water). That force is what can rupture the cells. By adding water the yeast is already hydrated and the pressures exerted by the wort's gravity are much lower. In theory, you should probably rehydrate it before adding it to your mini-starter which will exert similar pressures as a 5g batch.

Baron von BeeGee said:

Not that...the yeast is dry so it wants to absorb wort (which has a much higher gravity than water). That force is what can rupture the cells. By adding water the yeast is already hydrated and the pressures exerted by the wort's gravity are much lower. In theory, you should probably rehydrate it before adding it to your mini-starter which will exert similar pressures as a 5g batch.

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I thought it was osmotic 'pressure', rather than mechanical pressure. So it's actually water from inside the yeast cells getting attracted to the concentrated wort, and getting drawn out of the cell, so the yeast dehydrates and dies.

Shambolic said:

I thought it was osmotic 'pressure', rather than mechanical pressure. So it's actually water from inside the yeast cells getting attracted to the concentrated wort, and getting drawn out of the cell, so the yeast dehydrates and dies.

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Osmosis inflicts a mechanical pressure on the cell walls. Dried yeast is, well, dry, so there's no water inside it. Due to the difference in density between the wort and the dried yeast cell it wants to absorb the wort rapidly via osmosis. This inflicts a mechanical pressure which may rupture the cell wall. This risk can be greatly reduced by rehydrating with water (much lower density than wort, and hence lower pressures).

Here's a pretty good article for a more in-depth explanation than I can provide:
http://oz.craftbrewer.org/Library/Methods/Sanders/YummiesForYeast.shtml

I agree with BeeGee here as well. If we are talking about Osmosis, it is simply diffusion of water. This means that the water, which can passively move through the cell membranes, is going to go from high concentration to low conentration. The yeast cells are, like we all agree on, dehydrated, thus they have no water. This would mean that the water concentration outside the yeast is much higher than it is inside the yeast (even in wort) and the water is going to diffuse into the cells (osmosis) which could cause the cells to swell and burst, thus rehydrating is a good idea

clayof2day said:

I agree with BeeGee here as well. If we are talking about Osmosis, it is simply diffusion of water. This means that the water, which can passively move through the cell membranes, is going to go from high concentration to low conentration.

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Osmosis occurs because water tends to move from regions with a low concentration of solute to regions with a higher concentration of solute.


Anyhoo, I think we're getting a bit

Exploding yeast cells. What will they think of next?