Help with Radler

[Two Wheeler]

I brewed 6.5 gallons of a traditional Kolsch on Sunday and it's fermenting away nicely at this point. My plan is to keep 3.5 gal of the base beer, but use the other 3 gal to make a radler. I'm shooting more for the Moose Light version than the traditional version. Their radler is 15% juice, mostly grapefruit with lemon and grape juice I beleive. I want to add the juice into the keg to make it easy to serve.

I see two issues:

• Refermentation
• Blending

Somehow I need to kill off the yeast before adding the juice. I've heard that camden tablets will work... any experience with how much will work, and any associated off flavours? I'm sure Moosehead heat pasteurizes their beer, but I don't see an easy way to do this without oxidizing the beer.

And how well will the beer and juice blend in the keg?

It's for the girlfriend... I swear...

Thanks!

[Roger]

If you add the juice before the beer it should mix it self and you could chemically kill the yeast or pasteurise it somehow. But for all the potential issues why don't you get your girlfriend to add some juice to her glass before filling with beer... That way the base beer can also be enjoyed. 

[Two Wheeler]

why don't you get your girlfriend to add some juice to her glass before filling with beer... That way the base beer can also be enjoyed. 

Haha... I said I could brew a radler and now need to deliver. I did some more reading this morning... at serving temp (4c) the yeast should be dormant anyway and not be an issue.

[Roger]

why don't you get your girlfriend to add some juice to her glass before filling with beer... That way the base beer can also be enjoyed. 

Haha... I said I could brew a radler and now need to deliver. I did some more reading this morning... at serving temp (4c) the yeast should be dormant anyway and not be an issue.

Should be... 

[brew]

why don't you get your girlfriend to add some juice to her glass before filling with beer... That way the base beer can also be enjoyed. 

Haha... I said I could brew a radler and now need to deliver. I did some more reading this morning... at serving temp (4c) the yeast should be dormant anyway and not be an issue.

Heh heh! Depending on how long it takes you to drink it as well, it will still condition and the yeast may not necessarily be done with your beer, especially with all that nice juice you added. Kolsch yeast is particularly resilient at lower temps, while not a lager yeast, it does work well at lower temps. If you're serious about stopping the yeast at a particular OG you should really camden the beer. We have mead threads on here that talk about that, @Richard did some experimenting and @JohnQ does this regularly with his meade's...

[Two Wheeler]

Update here... Based on @Kyle 's LSA radler post, I added 1l of Grapefruit Juice and 1.5 TBSP of lime juice to my 2.5 gal of Kolsch. It is not good. For some reason the Kolsch finished super low at 1.003 so I think it's missing the required sweetness to offset the sourness of the juice.

I think I'm going to pick up some Lactose and add it to taste


Edit: The Kolsch finished at 1.003, then I added 1 camden tablet and the juice mix and it has not gone about 4.5 deg celsius, preventing further fermentation (hopefully).

[Kyle]

I find Kolsh to be very estery. likely that is interfering with the juice taste. personally mine was nice and tart, quite similar to the Rickards radler but mine was more beery. I would not add any source of sweetness. In pursuit of good recipes there are bound to be some great ones and some misses... part of the joy of experimenting