[chezteth]

Greetings. I brewed a RIS about a month ago. It started at 1.095. It seems to have stopped at 1.040. I pitched yeast slurry from a 10 gal batch of English Mild that I kegged the same day I brewed the RIS. I have checked the FG twice now, several days apart, with the same reading.

8.0kg briess pale ale
360g black malt
100g chocolate malt
454g extra special malt
400g roasted barley
2kg munich 10L
200g carafa II

Danstar Windsor Ale yeast

Mashed at 152°F for 60 minutes. Fly sparged. Fermented at 62 for 3 days then ramped up to 70 for the remainder. Perhaps I should have increased the temperature sooner.

It tastes like it is underattenuated. Would you recommend adding more, higher attenuating yeast at high krausen to finish the fermentation?

Cheers,
Brandon

[S. cerevisiae]

Your fermentation is not stuck. Windsor cannot ferment maltotriose, which is why you have a high terminal gravity (i.e., Windsor is not the best yeast strain to use with beer styles above 10 to 11 Plato).  You have to deal with a double whammy at this point in that you cannot vigorously aerate a batch that is currently sitting at over 7% ABV.  My suggestion is to pitch 20 grams of the yeast strain that I like to refer to as the Terminator (a.k.a. K1V-1116 or Montpellier).  K1V-1116 (Lalvin K1-V1116) is one of the best kept secrets in high gravity brewing.  Unlike most wine yeast strains, K1V can ferment maltotriose.  K1V is an S. cerevisiae wine strain that is good to 18%.  It also emits a killer toxin that inhibits all other microflora in the fermentation; hence, the name Terminator.  Best of all, K1V is well known for its ability to restart a stalled or under attenuated high gravity fermentation.  K1V is POF- (phenolic off-flavor negative).

[Wort-H.O.G.]

Your fermentation is not stuck. Windsor cannot ferment maltotriose, which is why you have a high terminal gravity (i.e., Windsor is not the best yeast strain to use with beer styles above 10 to 11 Plato).  You have to deal with a double whammy at this point in that you cannot vigorously aerate a batch that is currently sitting at over 7% ABV.  My suggestion is to pitch 20 grams of the yeast strain that I like to refer to as the Terminator (a.k.a. K1V-1116 or Montpellier).  K1V-1116 (Lalvin K1-V1116) is one of the best kept secrets in high gravity brewing.  Unlike most wine yeast strains, K1V can ferment maltotriose.  K1V is a S. cerevisiae wine strain that is good to 18%.  It also emits a killer toxin that inhibits all other microflora in the fermentation; hence, the name Terminator.  Best of all, K1V is well known for its ability to restart a stalled or under attenuated high gravity fermentation.  K1V is POF- (phenolic off-flavor negative).

will K1V rip it to shreads...resulting very low FG?

[Stevie]

Your fermentation is not stuck. Windsor cannot ferment maltotriose, which is why you have a high terminal gravity (i.e., Windsor is not the best yeast strain to use with beer styles above 10 to 11 Plato).  You have to deal with a double whammy at this point in that you cannot vigorously aerate a batch that is currently sitting at over 7% ABV.  My suggestion is to pitch 20 grams of the yeast strain that I like to refer to as the Terminator (a.k.a. K1V-1116 or Montpellier).  K1V-1116 (Lalvin K1-V1116) is one of the best kept secrets in high gravity brewing.  Unlike most wine yeast strains, K1V can ferment maltotriose.  K1V is a S. cerevisiae wine strain that is good to 18%.  It also emits a killer toxin that inhibits all other microflora in the fermentation; hence, the name Terminator.  Best of all, K1V is well known for its ability to restart a stalled or under attenuated high gravity fermentation.  K1V is POF- (phenolic off-flavor negative).

Mark - This, in my opinion, is the best bit of info you have shared to date. This is getting locked into memory from here out.


Edit - Changed from Marc to Mark - Sorry man.

[S. cerevisiae]

will K1V rip it to shreads...resulting very low FG?

No, K1V will just finish off the maltotriose.  There is a Saccharomyces yeast species that will rip a fermentation to shreds, but it is considered to be spoilage species.  It is called Saccharomyces diastaticus (S. diastaticus).  As you have more than likely ascertained from the species name, S. diastaticus excretes enzymes that can break down dextrin, leading to super attenuated beer.

[Wort-H.O.G.]

will K1V rip it to shreads...resulting very low FG?

No, K1V will just finish off the maltotriose.  There is a Saccharomyces yeast species that will rip a fermentation to shreds, but it is considered to be spoilage species.  It is called Saccharomyces diastaticus (S. diastaticus).  As you have more than likely ascertained from the species name, S. diastaticus excretes enzymes that can break down dextrin, leading to super attenuated beer.

yes, great info..thanks.

[erockrph]

Your fermentation is not stuck. Windsor cannot ferment maltotriose, which is why you have a high terminal gravity (i.e., Windsor is not the best yeast strain to use with beer styles above 10 to 11 Plato).  You have to deal with a double whammy at this point in that you cannot vigorously aerate a batch that is currently sitting at over 7% ABV.  My suggestion is to pitch 20 grams of the yeast strain that I like to refer to as the Terminator (a.k.a. K1V-1116 or Montpellier).  K1V-1116 (Lalvin K1-V1116) is one of the best kept secrets in high gravity brewing.  Unlike most wine yeast strains, K1V can ferment maltotriose.  K1V is an S. cerevisiae wine strain that is good to 18%.  It also emits a killer toxin that inhibits all other microflora in the fermentation; hence, the name Terminator.  Best of all, K1V is well known for its ability to restart a stalled or under attenuated high gravity fermentation.  K1V is POF- (phenolic off-flavor negative).

What's your procedure for using K1V in a stalled fermentation? Do you make a small starter and pitch at high krausen, or just rehydrate and pitch? Also, is there an ABV cutoff where it's too high to bother? I have a few meads in the 14% range that finished a little sooner than I'd like. I'd love to chip off another 10-20 gravity points of some of them.

[S. cerevisiae]

What's your procedure for using K1V in a stalled fermentation? Do you make a small starter and pitch at high krausen, or just rehydrate and pitch? Also, is there an ABV cutoff where it's too high to bother? I have a few meads in the 14% range that finished a little sooner than I'd like. I'd love to chip off another 10-20 gravity points of some of them.

I just rehydrate K1V in a small amount of boiled and cooled water.  I made the mead that I have had sitting in a secondary for quite some time with K1V.  It stalled because the pH dropped too low.  I buffered the pH up with potassium carbonate, and it went back to work.  The original gravity for this mead was 1.135.  It was sitting at a little over 17% when I racked it.

[HoosierBrew]

What's your procedure for using K1V in a stalled fermentation? Do you make a small starter and pitch at high krausen, or just rehydrate and pitch? Also, is there an ABV cutoff where it's too high to bother? I have a few meads in the 14% range that finished a little sooner than I'd like. I'd love to chip off another 10-20 gravity points of some of them.

I just rehydrate K1V in a small amount of boiled and cooled water.  I made the mead that I have had sitting in a secondary for quite some time with K1V.  It stalled because the pH dropped too low.  I buffered the pH up with potassium carbonate, and it went back to work.  This original gravity for this mead was 1.135.  It was sitting at a little over 17% when I racked it.

This is good info. I"ve never pitched Lalvin for this before. Mark, generally speaking, how well would you expect this yeast to finish the job on a beer - on a par with 1056?  Better?  I know grist fermentability plays a big role. I pitch enough healthy yeast to get the job done and give good attenuation - just curious.

[S. cerevisiae]

This is good info. I"ve never pitched Lalvin for this before. Mark, generally speaking, how well would you expect this yeast to finish the job on a beer - on a par with 1056?  Better?  I know grist fermentability plays a big role. I pitch enough healthy yeast to get the job done and give good attenuation - just curious.

K1V can produce floral and fruity esters when pitched early in a fermentation.  However, it tends to behave itself when used as a batch salvage yeast.  There was a brew pub in Canada that used K1V as its house yeast strain.

[chezteth]

Awesome! Thanks for the advice, Mark. As others have said, this will be put away to memory. I may actually have some K1V in the refridgerator.
Cheers,
Brandon