Flavor profile of a young kölsch?

[bwarbiany]

My first batch with RO water was a kölsch. I brewed it on Jun 30. Admittedly the yeast I used was a bit old. I had gotten it from Brent at the end of April with the expectation to brew immediately and ended up holding off 2 months to wait to get my RO system going. That said, I did make a starter and fermentation seemed to go okay.

The beer is now 5 weeks old. Fermented for ~2 weeks, cold crashed in the fermenter for a week, and it's now been carbonating in the keg for nearly 2 weeks.

The beer tastes a bit off. It has a beautiful pils nose, but there's something just a bit off in the flavor. I'm not sure how to describe it -- I'll try to get a better description this evening.

But I'm wondering whether I'm just drinking it too young. I was a bit higher on the OG than planned at 1.056, so I would assume that the lagering process should take a bit longer than 3 weeks.

Has anyone drank a kölsch too young? What sort of flavors did you get?

[bwarbiany]

Drinking it, I'm not getting sour, tart, or vinegar. Not even green apple... More a nondescript "bite".

Maybe I just need to leave it alone a few weeks...

[JonW]

What's your CO2 volume? Maybe a CO2 bite?

[bwarbiany]

What's your CO2 volume? Maybe a CO2 bite?

Doubtful. I'm probably in the 2.7 vol ballpark, but I did the "set and forget" carb method, not burst carbing...

[brahn]

I've never had a problem with drinking them too young. I don't even lager them, other than by keeping them in the serving fridge on tap. I've never noticed the flavor changing significantly from the first pint to the last.

"Bite" doesn't give much to go on. Like Jon suggested it could be co2, maybe your mineral additions (or lack thereof), yeast health, etc.

[bwarbiany]

Well, I had one last night, and it did seem smoother...

I'm not sure what to make of it. Perhaps I need to bottle a few up and we need to have another homebrewer lunch for me to distribute them to you guys for analysis!

[SamIam]

I'm no expert in doing a kolsch but I've done RO water on my last 8 or 9 batches which included a pilsner. What water additions and amounts did you add? When and where did you add them? What was your mash and finished beer pH? How long was your RO water sitting around before you used it?

[bwarbiany]

I'm no expert in doing a kolsch but I've done RO water on my last 8 or 9 batches which included a pilsner. What water additions and amounts did you add? When and where did you add them? What was your mash and finished beer pH? How long was your RO water sitting around before you used it?

In 20 gal of RO water, I added 10g CaCl2 and 7g gypsum. That was equally distributed between mash and sparge as I added it to the water before measuring out my mash.

I didn't check pH.

The water was sitting about 24 hours between making it and brewing with it. Does that make a big difference?

[SamIam]

Those amounts seem ok. I'm out of town until Friday but when I get back home I'll post up my additions and amounts I used in my pilsner. The main difference I do is I split the additions between my mash and BK. I don't add anything to my sparge water. I feel you can control the ppm better this way because I seldom use all my sparge water.

What is strange is on my last batch, a hoppy red, has a bit of a bite to it as well. I usualy have to acidify my mash a bit but for some reason my mash pH came in at 4.85 without adding any acid. I still don't know how or why this happened. The finished beer has a pH of 4.5. So I'm attributing the bite to having a low pH.

My water was filtered about 24 hours before brewday as well and its never been a problem before. I don't think it was this time either but RO water is pretty unstable.

I have a pH meter if you want to pull a sample and check it?

[bwarbiany]

My water was filtered about 24 hours before brewday as well and its never been a problem before. I don't think it was this time either but RO water is pretty unstable.

What makes it unstable? I ask because I prepared RO water just before leaving for vacation, thinking I was going to brew my Oktoberfestbier *before* leaving. Time got away from me and I couldn't do so, and I ended up brewing the following weekend. I smelled the water to ensure that there was nothing growing in it, and it seemed fine, so I figured it was good for brewing.

If that's a bad practice, it would be helpful to know.

I have a pH meter if you want to pull a sample and check it?

I bought one too... One of these days I should figure out how to use it!

I didn't buy any calibration solution yet. How critical is that?

[SamIam]

What makes it unstable is it has no buffering ability. So even the smallest amount of base or acid will drastically swing the pH one way or the other.

I think it important only if you want it accurate. If you haven't calibrated it yet then I would do so before you use it. I did mine when I first got it the check it every few brews.

[bwarbiany]

It's definitely smoothing out... I'm wondering if it might have been yeast bite going away as it continues to clear.

It's not often that I've had much luck with simple, delicately-flavored beers, and I wonder if just letting the subpar water get out of the way and replacing it with RO maybe made me notice the yeast bite much more prominently?

[brahn]

I don't know why I didn't mention it before, but that yeast will throw off a lot of sulfur if it's underpitched. In my experience it's always mellowed out by the end of fermentation. Maybe the bite you're getting is some residual sulfur. If that's the case it will most likely fade and the beer should be fine.

[bwarbiany]

I don't know why I didn't mention it before, but that yeast will throw off a lot of sulfur if it's underpitched. In my experience it's always mellowed out by the end of fermentation. Maybe the bite you're getting is some residual sulfur. If that's the case it will most likely fade and the beer should be fine.

1.5L starter in ~11 gal of 1.055 wort. Pitched at high krausen rather than letting the starter truly finish.

So slight underpitching may be it...

[brahn]

I'd say that's considerably underpitched. If I were starting from a single vial of yeast and using a stir plate, I'd be going for about a 4.5L starter based on those numbers.

I think I gave you around 150-200ml of slurry, which is a good quantity for that beer, but it was also a few months ago. Checking the yeast calculator and when I think I harvested that yeast, it says you'd need about 2L of slurry now. It's hard to say exactly working from the slurry, but I'd definitely have done a 4+ liter starter for that beer.