Author Topic: Forced Fermentation Test  (Read 8631 times)

Offline tubercle

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Re: Forced Fermentation Test
« Reply #15 on: January 26, 2011, 04:23:57 PM »

AFAIK no wine yeast strains can ferment maltotriose....

  Hmmm....

 I wonder if they could be trained?

Make starter-size batch after batch after batch and maybe over time they would mutate.

I wish I had more time on my hands.
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Offline tschmidlin

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Re: Forced Fermentation Test
« Reply #16 on: January 26, 2011, 04:45:06 PM »

AFAIK no wine yeast strains can ferment maltotriose....

  Hmmm....

 I wonder if they could be trained?

Make starter-size batch after batch after batch and maybe over time they would mutate.

I wish I had more time on my hands.
If bacteria can mutate to use a man-made molecule like nylon as a carbon source, I'm sure yeast can develop an enzyme for maltotriose.  And Lenski's work with bacteria in citrate shows they can mutate to use that.

The key will be to give them an abundance of maltotriose, so that as soon as one cell mutated to use it it would have a large competitive advantage over the other cells in the culture.
Tom Schmidlin

Offline tubercle

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Re: Forced Fermentation Test
« Reply #17 on: January 26, 2011, 04:46:51 PM »

AFAIK no wine yeast strains can ferment maltotriose....

  Hmmm....

 I wonder if they could be trained?

Make starter-size batch after batch after batch and maybe over time they would mutate.

I wish I had more time on my hands.
If bacteria can mutate to use a man-made molecule like nylon as a carbon source, I'm sure yeast can develop an enzyme for maltotriose.  And Lenski's work with bacteria in citrate shows they can mutate to use that.

The key will be to give them an abundance of maltotriose, so that as soon as one cell mutated to use it it would have a large competitive advantage over the other cells in the culture.

 Tubercle has work to do ;D
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Offline tschmidlin

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Re: Forced Fermentation Test
« Reply #18 on: January 26, 2011, 04:48:49 PM »
Tubercle has work to do ;D
Lenski's work was surely funded by a grant, you might want to start writing one :)
Tom Schmidlin

Offline seajellie

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Re: Forced Fermentation Test
« Reply #19 on: January 26, 2011, 08:04:40 PM »
Thanks for the replies and good info everyone. I never would've guessed that bread yeast could act as a delegate for beer yeast better than wine could.

I found numerous sources putting the percent of maltotriose in beer wort to be around 13 - 14% (Malting and Brewing Science says 13.6% is typical). I did not see any info that indicated that Munich malts were an exception to this number. Briess puts most of their LME's (including the Munich) at 13 or 14% maltotriose. Their black malt LME was considerably lower at 8%.

So I guess I could put a rough FFT for this test at 20 - (56 x .136) => 1.012 or 1.013. roughly.

To quote from Danstar's website:

Beer yeast usually can ferment maltotriose, most wine yeast cannot. To me there is no big deal if the yeast cannot ferment the maltotriose. The mashing procedure can minimize the amount of maltotriose present in the wort and the unfermented maltotriose just gives you more body, mouth feel and perhaps a slight sweetness.

Turns out, this is one of two main ways to tell wine yeast from beer yeast. Here's the other, also from Danstar:

1. Phenol off flavor or POF test. Most beer yeast are POF negative. A few of the wine yeast that I have tested were POF positive.

FWIW, the FFT with wine yeast tasted unpleasantly familiar; it reminded me of bad home brew I had back in the 1990s, and which was the reason it took me a long time to try out this hobby! A bit like apricot bread that was funky.


Online Kaiser

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Re: Forced Fermentation Test
« Reply #20 on: January 26, 2011, 08:43:01 PM »
So I guess I could put a rough FFT for this test at 20 - (56 x .136) => 1.012 or 1.013. roughly.


Nice analysis, but I think you'll have to work with real attenuation and not apparent attenuation.

The apparent attenuation in your FFT is 64% which meas that 53% of all the sugars fermented (real attenuation). Now add another ~13% for the maltotriose and you'll get a real attenuation potential of 66% for the beer. Calculating this back to the FG gives you 1.011.

Kai

Offline seajellie

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Re: Forced Fermentation Test
« Reply #21 on: January 27, 2011, 06:40:19 AM »
Right you are Kai, of course. I was aware last night that apparent/actual attenuation would affect the numbers, but I didn't think it would be by as much as 0.002 since we were dealing with only a portion of the OG. I was too uninspired (or lazy) to do the math properly, but that's an important difference considering the purpose of this exercise. Cheers!

I was also thinking other (unknown) factors could affect the result so that stopped me from going further. One possible factor being maybe WL833 can deal with a small portion of the higher saccharides better than wine yeast. I know most of these won't get metabolized at all. And a bigger one was this odd fact I found on Danstar's site too. And those wishing to train yeast in their spare time may be interested in this wine yeast which acts very much like a beer yeast. At the risk of getting anyone started on yeast taxonomy....

There is one very famous wine yeast that is both POF negative and can ferment maltotriose. It is probably the largest selling wine yeast strain in the world. It is Lalvin K1-V1116. It was used in a beer kit for several years and it was the yeast of choice in a Canadian brew pub for several years.

That threw me, because my memory was telling me that I had used a yeast with a very similar number to that -- a possible relative, if not in fact that same yeast. Which only takes me down all sorts of new roads.

all in all, I think I'll just use bread yeast next time like Kai  suggests  :)
« Last Edit: January 27, 2011, 06:56:04 AM by seajellie »

Offline a10t2

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Re: Forced Fermentation Test
« Reply #22 on: January 27, 2011, 08:54:16 AM »
There is one very famous wine yeast that is both POF negative and can ferment maltotriose. It is probably the largest selling wine yeast strain in the world. It is Lalvin K1-V1116. It was used in a beer kit for several years and it was the yeast of choice in a Canadian brew pub for several years.

Ooh, good find. Looks like that one's actually S. cerevisiae: http://www.lalvinyeast.com/images/library/ICV-K1_Yeast.pdf

Might be fun to try it out in a beer wort.

The key will be to give them an abundance of maltotriose, so that as soon as one cell mutated to use it it would have a large competitive advantage over the other cells in the culture.

And for best results, apply regular doses of ionizing radiation.
« Last Edit: January 27, 2011, 08:57:23 AM by a10t2 »
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