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Squatchy
12-31-2014, 05:09 PM
2 questions!

1 Will the common yeast that we use live peacefully with each other or will they compete? Can you blend them if they are the same species?

2 If you were to pitch one packet as opposed to 3 or 4 would they become over populated and then stress, or do they stop propogating once they have obtained what ever population the caring capasity of the vessel is? Wouldn't more yeast make for a faster ferment? Must be something wrong with this approach because it's not used.

Comments???

Ryan

loveofrose
12-31-2014, 09:56 PM
1. It depends. Some yeast have a "killer factor". Yeast either have the killer factor and are immune, sensitive to the killer factor, or do not have the factor and are not sensitive. Lalvin has a list of its yeast and whether they have the factor or not or immunity to the factor. Blending is possible as long as you match up competitor factors correctly and this has been done to great effect in beer. Lalvin publishes the killer factor status of their yeast. Ale yeast is more of a guessing game.

2. Over pitching does exist, but it is very difficult for a homebrewer to achieve it without great expense. It is mostly a brewery issue. More is better to a point, but too much can be bad. Generally, 15-20 million yeast per milliliter is suggested for 1.100 gravity. This equates to ~50-65 billion yeast per gallon. A smack pack is theoretically 100 billion, but a lot of death occurs in transit. I estimate a smack pack will do a gallon, but outside of that make a starter.


Better brewing through science!

Medsen Fey
12-31-2014, 10:23 PM
You can make a good mead with a large biomass yeast pitch - see the HotMead Yeast Test. However, there is evidence in the wine literature that suggests that you produce more aromatics during yeast growth and division, so pitching lower amounts might potentially produce meads with more bouquet. It needs further study.

Squatchy
01-01-2015, 12:36 AM
You can make a good mead with a large biomass yeast pitch - see the HotMead Yeast Test. However, there is evidence in the wine literature that suggests that you produce more aromatics during yeast growth and division, so pitching lower amounts might potentially produce meads with more bouquet. It needs further study.

So Medsen.

Am i correct in thinking we call that the lag phase? If so, wouldn't we benefit by "under pitching" to prolong the lag phase. That is providing we don't give enough of a leg up to the bad guys. I made a starter for a wyeast smack pack, not the BOMM yeast, a different one and it's so slow comming around that if I don't see progress by next year ( sorry, had to toss that in there :) ) i'm going to pitch it in the sink. I followed Bray's protocol, but it proofed so pourly , before I even opened that smack pack that I had my doubts. 24 hours barely made a bulge in the packet. That was after I let it warm to room temp for 3 hours before I smacked. It's been in the starter for 16 hours so far and still no signs of life. I'm glad I didn't just pitch it from the sachet.

Squatchy
01-01-2015, 12:37 AM
I guess I should have reread your reply before I added my last piece. It's late and I've been up since 4 A.M.

Squatchy
01-01-2015, 12:45 AM
Hey LOR :)

Do you know from your reading, what affect mixing yeast has done in the beer camp? I was reading here about the "anchor yeast" mixed with a longer lasting/higher tolerance yeast to finish of the ferment. It amazes me how, Mead is the oldest drink on the planet, and yet, it still seems like it is the least developed. Imagine how it will progress once it becomes profitable enough for the big dogs (National/world brewers) to jump in.

WVMJack
01-01-2015, 07:38 AM
Squatchy, you might be interesting in reading about the progression of yeast in a wild ferment that has a mixed population. Some yeasts grow fast but fade with low alcohol levels while some of the tougher ones grow slower but can withstand the higher alcohol levels and take over. This seems to be a fashion now to do wild ferments, of course they are fraught with danger as some of the wild guys can gain the upper hand or some of the yeasts can stress out and make a big stink about it. Several ways to promote the good yeasts like low KM treatment. All the introducing different yeasts are sort of on this progression of the different yeasts. Do you have a purpose for wanting to do this in mind? WVMJ

Medsen Fey
01-01-2015, 09:12 AM
Am i correct in thinking we call that the lag phase? If so, wouldn't we benefit by "under pitching" to prolong the lag phase. That is providing we don't give enough of a leg up to the bad guys.
Lag phase is a term that has little meaning to the yeast. So there is active growth and division during and after lag phase until they reach a steady-state concentration of cells. Under-pitching might very well prove beneficial but it needs to be tested. Beer guys have a lot of anxiety about the size of their pitch because they don't aerate after pitching. This is why they have to get a large-enough starter. Since we aerate regularly, our entire batch become the starter so even a small pitch can eventually grow and multiply enough to get the job done.

With that said, as WVMJack points out, this may allow wild things in your must to have more time to grow and create their character in your must. Could be good - Could be bad. It depends on what is growing around your brew area, and what wild spores are in your honey.


I made a starter for a wyeast smack pack, not the BOMM yeast, a different one and it's so slow comming around that if I don't see progress by next year ( sorry, had to toss that in there :) ) i'm going to pitch it in the sink. I followed Bray's protocol, but it proofed so pourly , before I even opened that smack pack that I had my doubts. 24 hours barely made a bulge in the packet. That was after I let it warm to room temp for 3 hours before I smacked. It's been in the starter for 16 hours so far and still no signs of life. I'm glad I didn't just pitch it from the sachet.

Patience...

Squatchy
01-01-2015, 10:54 AM
. Do you have a purpose for wanting to do this in mind? WVMJ

No. Just a curious mind.

I guess it woIuld be nice if we could make higher AVB that didn't require such a long time to mello out. Or a faster fining done by scavenger yeast additions in secondary that would eat the Mead clean and then fall out of suspension. Those are the only things that come to mind while I sit here typing.

mannye
01-04-2015, 05:46 AM
I have also been curious about this for developing different character in mead by blending yeast profiles. I don't know if that's a question of simply blending finished meads made by the yeasts I want to blend or if actually making them work together and, I guess, potentially use each other as food will make for a different result.

Medsen Fey
01-04-2015, 10:39 AM
Blending gives you a lot more control over the outcome than trying to get mixed fermentations to be consistent.