After reaching FG on a recent batch of Evil Twins, a 10 G batch split on 2 yeasts I put both 5G kegs into a chest freezer set at 38 degrees. My questions are;

A. Was this a mistake & not the best long term storage option? Can i take them out and back to room temp?
B. What is the best storage option for kegged beer or is it ok to let it sit cold and carb cold?
C. Will it effect flavors or hop aroma/bitterness?

I know some styles may benefit from a cold "conditioning(?)" or "lagering" period. But curious about the general guidelines for storing until carbing (i force carb).

Sorry for the shit-ton of questions but we put some hard work into these beers and i want them to be the best tasting they can be.

Thanks.

General rule of thumb is that cool is better than warm. If you did pick up oxygen, warm temps are going to accelerate staling reactions and other things you don't want happening in your beer. They may not need to be stored that cold, but probably won't hurt them.

I store all of my carbed kegged beer at 35F. I feel that this helps to keep the beer as fresh as possible. Serving it too cold does suck, but I usually will warm up my glass with some hot water then make a pour, or better yet, pour a couple beers and let them sit for 20 min. or so to warm up while I take care of some other shit around the house.

Yes, you did nothing wrong, in fact you did everything RIGHT! Storing beer cold all the time is one great thing about fresh homebrewed beer. It never has to sit on a warm shelf!

Since Spidey brought this up, preventing oxygen pick up is even more important than storing cold. Cold storage is surley the best way to go, AND if you can do a closed transfer from fermenter into a purged keg pushing with CO2 and not pick up any O2 you will be way better off, really.

You would want to let the carboys sit a couple days at fermentation temps to clean up any fermentation by products. Then its fine to transfer to keg and store cold .

I like to hook up the gas right away and carb as the beer is cooling to keep the keg under positive pressure. As the beer cools, a vacuum will form in the keg and suck in air, wild yeasts, molds, etc from the refrigerator if the keg isn't sealed.

Don't you purge your kegs to seat the lid after transferring?

Me? I purge when the keg is full of sanitizer and then push the sanitizer with co2 into the next keg to be santized. Beer is pushed/siphoned also by CO2 but with the gas ports linked to allow the pressure to equalize.

I read the OP to mean he was storing in a keg uncarbed. I read that as not pressurized.

How much of a decrease in pressure is expected by chilling from say 70°F to 35°F?

It would depend on how much headspace you have. Gasses will contract more than liquid, so if you have a half full keg that you chill down, it will be under more negative pressure than if you chill down an entirely full one.

I think brewinhard was wondering about your post that seemed that you were talking about not closing kegs when full and chilling?