Author Topic: k-97 for a stout or dark brown?  (Read 2160 times)

Offline PORTERHAUS

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Re: k-97 for a stout or dark brown?
« Reply #15 on: February 04, 2021, 12:58:11 pm »
If WB06 is closely linked to the culture used to ferment Duvel, it is actually of Scottish origin.  Duvel's culture was isolated by Jean DeClerk from a mixed culture found in a bottle of bottle-conditioned McEwan's scotch ale.

yup, i listened to a 50 min long beersmith show with ron pattinson as the guest on scottish ales that was illuminating. i would bet they would have been using POF+ yeasts at the time. a lot of conceptions people have about scottish historic beer are very very wrong.


Did you end up using the K-97 in the Stout? How did it turn out?

Offline fredthecat

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Re: k-97 for a stout or dark brown?
« Reply #16 on: February 04, 2021, 02:58:41 pm »
If WB06 is closely linked to the culture used to ferment Duvel, it is actually of Scottish origin.  Duvel's culture was isolated by Jean DeClerk from a mixed culture found in a bottle of bottle-conditioned McEwan's scotch ale.

yup, i listened to a 50 min long beersmith show with ron pattinson as the guest on scottish ales that was illuminating. i would bet they would have been using POF+ yeasts at the time. a lot of conceptions people have about scottish historic beer are very very wrong.


Did you end up using the K-97 in the Stout? How did it turn out?

nope, ended up making just some pale ale. DME, crystal 60 and a little victory. copious amarillo, el dorado and EKG hops to about 40 IBU. i was going to report on it when i transfer it in a few days. just dry hopped it yesterday.

the krausen will not dissipate. its a practical problem as ive got dry hops resting on top of it.

Offline Saccharomyces

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Re: k-97 for a stout or dark brown?
« Reply #17 on: February 04, 2021, 04:36:28 pm »
nope, ended up making just some pale ale. DME, crystal 60 and a little victory. copious amarillo, el dorado and EKG hops to about 40 IBU. i was going to report on it when i transfer it in a few days. just dry hopped it yesterday.

the krausen will not dissipate. its a practical problem as ive got dry hops resting on top of it.

Interesting,  I always dry hop in the keg.   That practice stems from my love of Oxford Real Ale, which was dry hopped in the keg.

Offline fredthecat

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Re: k-97 for a stout or dark brown?
« Reply #18 on: February 04, 2021, 04:51:14 pm »
nope, ended up making just some pale ale. DME, crystal 60 and a little victory. copious amarillo, el dorado and EKG hops to about 40 IBU. i was going to report on it when i transfer it in a few days. just dry hopped it yesterday.

the krausen will not dissipate. its a practical problem as ive got dry hops resting on top of it.

Interesting,  I always dry hop in the keg.   That practice stems from my love of Oxford Real Ale, which was dry hopped in the keg.

i dont use a keg. i plan to at a certain time in the future

Offline fredthecat

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Re: k-97 for a stout or dark brown?
« Reply #19 on: February 06, 2021, 04:24:22 pm »

Did you end up using the K-97 in the Stout? How did it turn out?

so again, for anyone else it was not a stout, 1.045 OG pale ale with EKG/amarillo/el dorado

i fermented it for 3 weeks  at mid 50s. yes that is too cold for it, so attenuation was only 75%.

the extremely solid head inhibited dry hopping in primary.

it tastes really clean with a tiny bit of sulfur. light apple ester, the breadiness that others mentioned is there, but not pronounced or bad at all. overall it feels like it emphasizes malt and hops equally. i used a lot of hops and while it feels right for the IBU (40), the hop aroma isnt totally exploding, at least yet uncarbonated. i detect no tartness that some people have mentioned about this yeast. no diacetyl.

it is very hazy at the moment despite using gelatin a few days ago.

i would absolutely use this yeast again, it tastes really really clean imho. haze looks really strong though, which i don't like.

if i had it 60F, or even if i finished it off at a higher temp than 55F, it likely would have hit 80% attenuation.

i would def use this for an alt-like beer.

i might post again when its carbonated, but again this yeast definitely feels like an ale, but is really clean. better than expected.

Offline fredthecat

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Re: k-97 for a stout or dark brown?
« Reply #20 on: December 14, 2021, 08:25:53 pm »
ok, so me, the long time crusader for the potential of k-97 has some results.

started an imp stout

1.082og, 84 IBU
2row, munich
15% by weight DME for gravity boost
1lb RB, 300g black malt

2 packs of k97 added 29 days ago.

chilled to ~60 for pitch, brought up to a ~66-68F ambient room for 7 days, massive ~5 inch krausen, once it died down and it seemed like no activity i brought it to a ~57-60F ambient room for the rest of the time. this yeast has always had the stupid temp suggestion on it of "12-25C" aka 54F to 77F

this yeast does not work properly at low temps or works extremely slowly.

after a month its down to 1.029  (64%) attenuation. yes its an imp stout, but the specialty grains are at 11% of total. i was expecting minimum 71-72%, ideally the 77% i believe fermentis estimates.

were the yeast packets old? (because no one wants k97?)
did i prematurely bring the temp down, ending the fermentation?
does the yeast just suck at attenuating or is greatly mislabeled like many fermentis dry yeast packages?



taste-wise, it is actually really good, so i am going to salvage it. the bitterness feels bracing even for 84 IBU. strong and decently nuanced roasted malt taste, chewy but frankly not as chewy as id expect for 1.029, clean, but the intense flavours may be hiding the much feared "breadiness" (not dismissing it, i just havent had a finished example to analyze fully yet). it is not excessively hazy/yeasty either with no gelatin added yet.

i secondaried it, adding a packet of WLP001 i had sitting around and i will give it another 2 weeks.

In short: i find the taste of the beer this yeast produces agreeable, but its fermentation characteristics are crap. would not recommend this for p much anything when there are so many alternatives.

Offline ynotbrusum

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Re: k-97 for a stout or dark brown?
« Reply #21 on: December 15, 2021, 04:13:45 am »
Maybe next time add some enzymes?
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Online dmtaylor

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Re: k-97 for a stout or dark brown?
« Reply #22 on: December 15, 2021, 04:48:19 am »
I wonder if this might be either a fermentation temperature thing, or a pH thing.  Do you recall the mash pH?  And what is the current pH?  With over a pound of dark roasted grains in there, depending on your water and alkalinity, etc., plus my hypothesis that it is a tart yeast anyway, the pH could be quite low, inhibiting fermentation or slowing it way down.  I would suggest fermenting it at room temperature for a week or two to see if it will pick up again, although racking to secondary did not help it at all, you just removed 90% of your yeast which probably aren't done fermenting yet.  I doubt the WLP001 is going to do anything additional, but again, the warmer temperature might help it to work.

So I see this more as a process issue or pH issue, than anything to do with yeast health or mislabeling on yeast packets, etc.

My conclusions with this yeast are similar to yours.  I won't use it again, because it produces mediocre results, and gives a lot of problems during fermentation / finicky.
Dave

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