I used CO2 to push the beer to CO2 filled kegs, so oxygen shouldn't be a problem. I then put the kegs in my chest freezer to carbonate, age, and cool to serving temps. Will the lacto still work at 40 degrees or should I take them back out and age for a while at 70?
Lacto likes it warm Eagle. I use the recipe in Brewing with Wheat. I omitted the hops entirely (my main adjustment,) and the wort is never boiled. Excellent results. In terms of souring, I allowed primary to finish around 68F and the carboy to warm to 79F. Warm conditioned for 2 months before racking the beer. I don't think you'll develop any sourness in the keg at fridge temperatures.
The mash regime in the recipe, lactic and carbonic acidity drives the mouthfeel in the beer. You'll need more CO2 on this than in most other beers. This is challenging in the bottle, no problem in the keg.
It is a really effervescent and refreshing style. This will be one of the presentations at NHC that I plan on going to. I've had a lot of success repitching the microbial cake into subsequent/representative worts. I'd like to know if others have had similar experience.