Safale K-97 questions

[MadCow182]

Hello all. I'm looking for input or suggestions on my current "kolsch" in the fermentation chamber. I've never used K-97 before but so far it seems to be as advertised with a think krausen on top. Here are the details:

Pitched yeast into 5G of 1.049 wort on 7/9 fermented at 15* C and according to my refractometer and the refractometer calculator on NB, it says that the gravity is currently 1.011 (7/13). Still plenty of airlock activity so it seems to be fairly active still and I wouldn't think it would ferment out in 4 days. My plan is to dial up the temp to 20* C for a few days for a diacetyl rest and take daily readings and if the gravity remains the same after that then rack to secondary for lagering.

With this being a top fermenting yeast, should I expect that the krausen will remain on top and never subside?

 

[Sir-Hops-A-Lot]

I agree with your plan to raise the temp and wait a few days. That should work. If the Krausen doesn't drop but the fermenting seems done, you can give at a shake and see if that works. If you have fridge with enough space you can do something called "Cold Crashing" - putting it in the cold to get the krausen to drop and the beer to get clearer.

 

[mattdee1]

I think you’re already at (or very close to) final gravity. I don’t think it’s a very good idea to take “daily readings” after you ramp up your temperature. If you’re careful it’s not an issue, but nonetheless, it is still unnecessary risk of causing problems with your beer. A better approach would be to just wait a stretch of a few days at the higher temperature (say 4-5, maybe up to 10 if you can muster the patience) and take a final confirmatory reading of your FG before proceeding to the next step. You may see that the gravity is still at 1.011, or you may see it has dropped slightly to 1.009 or so. Either way, it’s done fermenting.

I’ve never used that yeast, but I’ve used most of the common dry ale yeasts and I’ve never seen one where the krausen layer didn’t eventually sink back into the beer.

 

[MadCow182]

@mattdee1 Well, I feel like I'm pretty careful. I actually took a gravity reading before I read your response. It's at 1.008 now. I'll skip a few days and let it ride at 20* C The Krausen is still going strong but I think that's par for the course for this strain and I don't really expect it to go away until I crash it. I normally wouldn't be so aggressive with checking the gravity and would be completely content watching the airlock (I'm embarrassingly entertained by that) but being that the strain was new to me, I kind of wanted to watch it more closely. Then, after four days, I found out it was past what the listed FG on the recipe.

 

[Warrior]

Using this strain for the 1st time. Here's the starter for a 24 gal batch I'm making on Fri. Shows a true pancake type top crop as the German ale strain should. Going to make an Alt with this strain. I'll post how the beer comes out in about a month.

 

[dmtaylor]

"They" say K-97 is the same as Wyeast 1007, which means that the krausen will be slow to fall and might need to be racked out from underneath and gelatin added if you want to accelerate flocculation. I want to try the K-97 soon as 1007 might be my favorite yeast of all time maybe, and I've tried many dozens over the past 17 years.

 

[Warrior]

When ferment is done, I'll cold crash it to 36 degrees and see how well it flocs out. Yes 1007 is a very good strain, like it a lot!

 

[MadCow182]

Glad to see this post is still going.

@warrior: that's exactly what my fermentor looked like.

My K97 Kolsch turned out fantastic. I'm planning on starting another batch of it soon so to minimize downtime without it.

The krausen in my beer completely fell out after a few days at 35 degrees. I still clarified with gelatin because I try to get as clear as possible every time, just because I guess.

I've never used 1007 but I'm anxious to give it a try now.

 

[C-Rider]

I've made a few "German IPA's" using Munich as a base malt and K-97 yeast. Usually let it sit 3-4 weeks w/out looking at it. Get a good brew all the time.

 

[Warrior]

Check this out 24 hrs after pitching a starter I made for 24 gals. This is at 62 deg right now!

 

[Warrior]

Put beer in the cold area at 38 deg, all the yeast dropped from the top to the bottom of the fermenter. Should be kegging next week.

 

[davidst]

I have a beer I brewed with K-97, I kegged it after 2-3 weeks, it had a krausen for most of that time. It was still cloudy at 2 weeks and after about a month sitting in the keg (at 44 degrees) it's started to clear well. So far I've been disappointed, it's had a yeast twang in it the entire time (it was extremely strong for the first couple of weeks and since lessened, but I can still taste it, hoping after another few weeks in the keg it will finish clearing out). I doubt I'll use it again.

How was everyone else's results?

 

[bucketnative]

How was everyone else's results?

Last year, I brewed a couple of witbiers with K97. I used a 50% flaked wheat, 50% 2-row grain bill, some coriander and orange peel, very light Hallertau hops. The yeast gave it a very tart, refreshing taste compared to WLP400. Maybe not as traditional wit-tasting as most would like, but it was almost grapefruit-like in the tartness when combined with the spices and hops. I thought it was a very interesting beer, and I will be using this one again over the winter to get wits ready for spring.

I don't think I would use it for a Kolsch, since it doesn't have that Kolschy-taste... nothing beats 2565 in my opinion.

 

[UndeadFred]

I've had very, very good results with K-97, to the point that I'm almost thinking it is my favorite yeast. (But for only certain styles of beers)...

I should mention it's really marketed as "Kolsch" yeast (but I agree with a very neutral character.. it's almost like a high temp lager yeast).. and as such it needs to be fermented at the cold end of the range.. like 61-63F or so. I think if you would use it at 68F it would be way too aggressive. It's pretty aggressive at 62F. It does attenuate well, and doesn't flocculate super well, but gelatin seems to really work well with it. It was very neutral. It's like a US-05 that likes to be fermented 5-6F colder..

The two beers I did with the method above, two different styles came out really good. One was an American Blonde (and it's a great yeast for that), the other an American Amber (second pitch)...

I like it. It's like a cold fermenting US-05 or a warmer fermenting W34/70....

Having said that I don't think it would be a good yeast for beginners, without temperature control, I think it would be a disaster.

 

[Warrior]

Yes Undeadfred, you gotta have temp control with this strain, otherwise it gets very active! I agree that 60 to 62 deg is a good fermenting temp for it. I love the Alt I made with it. Just brewed a 90 Schilling with it last week. Can't wait to try that in about 3 more weeks.

 

[rhys333]

I have an American wheat in primary with this K-97 strain. The plan is to brew again tomorrow or the day after and top-crop yeast from one batch to the other.

Question is: what style to brew with it? Most recommended styles are too similar to the wheat, and I want some variety on tap. I thought about an American amber, leaning towards brown. I'm interested to hear from other based on their experience what works well...

 

[corax]

Question is: what style to brew with it?

I find it a nice, neutral yeast, and think it would be fine in any style where you weren't looking for obvious yeast character. Pretty much interchangeable with US-05 or Nottingham, in my opinion, but maybe even less likely to throw esters.

I've used it mostly for Kölsch-like blonde ales, but wouldn't hesitate to use it for American Amber or Brown.

 

[rhys333]

I find it a nice, neutral yeast, and think it would be fine in any style where you weren't looking for obvious yeast character. Pretty much interchangeable with US-05 or Nottingham, in my opinion, but maybe even less likely to throw esters.

I've used it mostly for Kölsch-like blonde ales, but wouldn't hesitate to use it for American Amber or Brown.

Sounds good. Thanks.

 

[ebbelwoi]

I did an altbier with it a few months ago. It came out fruitier than expected (fermented in low 60s) but it was quite tasty.

 

[Novims]

Isn't K-97 supposed to be an Altbier yeast? This thing refuses to flocc if you don't use gelatin.

 

[rhys333]

Isn't K-97 supposed to be an Altbier yeast? This thing refuses to flocc if you don't use gelatin.

If it's the same or close to Wyeast 1007 German Ale, then it should. For me, 1007 is cloudly for a few weeks and then drops crystal clear.

 

[rhys333]

I did an altbier with it a few months ago. It came out fruitier than expected (fermented in low 60s) but it was quite tasty.

I could do a bastardized Northern Altbier instead of calling it an amber. Something like:
80% base malt
15% munich 6
4% C120
1% BP for colour adjustment

 

[Steveruch]

I've used K-97 in an alt with good results and an American wheat, also with good results.
11 days ago I bottled a sorta grodziskie that I used this yeast on. I, prematurely, opened one a couple of days ago and found it pretty good, but needing a few more days.

 

[hottpeper13]

I use 2565 and ferment a Black Kolsch with it, i would use K97 the same way. I use midnite wheat or the carafa malts to get just a hint of dark malt flavor. One of mt best beers is my October Kolsch

 

[rhys333]

I have an American wheat in primary with this K-97 strain. The plan is to brew again tomorrow or the day after and top-crop yeast from one batch to the other.

Question is: what style to brew with it? Most recommended styles are too similar to the wheat, and I want some variety on tap. I thought about an American amber, leaning towards brown. I'm interested to hear from other based on their experience what works well...

So I top-cropped the K-97 yeast today and was surprised to find completely pure yeast, free of all proteins and debris. Usually when I do this I have to scrape the crud away first, but not with this yeast. Even the sides of the fermentor were perfectly clean.

 

[ebbelwoi]

I think @skortjorkson mentioned a similar experience somewhere in this review:
https://www.homebrewtalk.com/thread...reated,brilliant with a refreshing bitterness.

 

[rhys333]

I think @skortjorkson mentioned a similar experience somewhere in this review:
https://www.homebrewtalk.com/thread...reated,brilliant with a refreshing bitterness.

I did read that, but was surprised by the krausen purity nonetheless.

 

[rhys333]

So... how is this stuff with warmer temps? We had an unexpected heatwave two days ago and my first batch got up to at least 72F. I ferment in a cool basement and can stick it on the concrete floor when it gets warm out, but I was caught unawares. It fermented out completely in two days.

Does it clean up okay with a D rest?

 

[rhys333]

Well it cleans up pretty well apparently. I just took a sample and despite warmer fermentation and just 8 days in primary, it's as clean as a whistle. I could keg it now, but will leave it another few days to be sure.

 

[couchsending]

So this is basically the same yeast genetically as 1007. I’m not 100% sure it’s acts exactly the same ( really with dry yeast who knows how much you’re actually pitching ) but if it was a healthy pitch it should act similar.

1007 basically doesn’t produce diacetyl. It’s popular amongst some larger professional breweries cause as soon as it hits terminal you can crash it. 1007 is also incredibly hardy. It can be abused and still ferments like normal. It’s also very clean across a wide range of temperatures. However it doesn’t flocc well at all so will need to be fined, filtered, or lagered for an extended time of you want clear beer. It produces some sulfur that will always be there but not really in an offensive way.