It'll make a beer, not a Kolsch - the Vienna Malt is out of place in it. Otherwise should be fine. Kolsch is very light colored. I think you're over-bittering it somewhat but that's your call. Having had a few in Cologne, the best description I can think of is Kolsch is slightly estery Helles. Don't get me wrong, assuming a reasonably sound process your recipe will make a pretty good beer but if you haven't gotten the maltiness you want in a Kolsch before, add some pale ale before darkening it significantly with Vienna.

My two cents only - As I said, I think your recipe will make a pretty good beer.

 

Mine is bare bones as well: Pilsner and acidulated malt. I use Spalt hops - more "northern German" than Hallertau.

 

I use Spalt, as well. And half a pound of Munich Dark. I still got the green check mark!

 

Matter of taste. My last Helles I intentionally darkened in the kettle. 2 hour boil. Matter of taste.

 

Kolsch malt best malz and spalter for hops if any a little munich but doesnt need it this is a yeast brew its all bout yeast and water.
https://www.brewersfriend.com/homebrew/recipe/view/372217/kolsch-2

 

There are some imports. Here in Denver I can get Sunner and Fruh from time to time, as well as another, can't remember it's name right now. Both are not representative of the fresh examples in Cologne but they're good examples. Go to a liquor store that has a bomber cooler and they may have an example or two. They're typically very light colored, some bready malt and fruit, fruit very subdued but there, hops enough to balance. Wouldn't mind at all being somewhere on the Rhein sipping one right about now or even one from the bottle with some of my friends on the Mosel....

 

I gotta believe most brewpubs that offer a Kölsch don't temperature control it. What say you?

 

Depends. I know our local brew pub has jacketed fermentors and they do lagers - why wouldn't they temp control their Kolsch? Even I do in my el cheapo basement rig. I'd think with a big fermentor - strictly guessing here - that you'd have to, the yeast would generate too much heat otherwise.

 

I suppose my thought was biased - I see nothing but ales offered at the brewpubs around me. Maybe most brewpubs do make lagers. Perhaps I should move to where the beer is better! I like me a lager for sure.

 

Colorado is the place to be, then.... But then, the brewery that's making my Kentucky Common can't even do step mashes. Other side, Bierstadt Lagerhaus in LoDo (Lower Downtown, specifically RiNo (River North), it's a Denver thing) has nothing BUT lagers! Prost, Tivoli, all places to knock back a good Helles here in the Mile High City (even more appropriate now that recreational pot is legal here). Our go-to craft brewery, the Dry Dock, had a head brewer trained at Weihenstephan in Germany so we get Helles, Pils, Schwarzbier, the gamut. Some of our guys are trying crazy stuff, pilsner with American hops just doesn't cut it. But we're lucky, beer is good here, even down to the little guys.

 

I'm a sucker for a Kölsch. I'll try it every time. I found one while I'm waiting for the Dayton Dragons to take the field.

 

Just about every local brewery around here has a "Kolsch". Most are just decent beers at best. A couple really do a great job and one in particular, St. Elmo, has about the cleanest, stylistically correct example I've ever had. It wouldn't be out of place coming out of a tap in Cologne.

 

Here's my latest tweak of my recipe:
https://www.brewersfriend.com/homebrew/recipe/view/481589/kolsch-2
As I mention in the notes, my intention was to just use Pilsner and about 5% Aromatic but when I went to mill for mashing, I found I was out. The small additions of Munich, Biscuit and CaraVienne that I substituted definitely added to the malty aroma and flavor. It all cleaned up very well for a just slightly full-bodied example of style that still finishes nice and crisp.
Turned out good enough to win the intra-club competition I was brewing for, not to mention being a killer summer beer to have on tap.

 

At about 94% Pilsner, it stayed pretty true to style, but if I subbed my local Pale Malt, it probably would make a killer APA. Since I don't do decoction, which would be the best way to go, I try to get a little more maltiness into the flavor profile.

 

Control the RA and mash pH, extend the boil for color, should be all that's needed.

 

Ah dam it now i want to brew one. Might just pick up sone Kolsch malt and spalt hops while im at the brew store this comming weekend.