There have been a few threads about chicken breasts, cooking temperature, and buttermilk.
I decided to do a little test.
I got a whole chicken, boned it, and took out two pieces of breast meat with skin removed. One piece was marinated in buttermilk for 24 hours, and the other nothing.
In separate bags, at the same time both were in the sous vide cooker for 90 minutes set at 150 F.
At the end of 90 minutes, both were quick seared on a cast iron skillet, buttermilk was washed off. No seasonings were used, just salt and pepper.
Mouth feel - Both were very tender, and juicy, pretty much identical, couldn't detect any difference.
Flavor - cooked at 150F, both were delicious with just salt and pepper, pretty much identical. I was unable to tell the difference between the two.
Chicken at $0.99 a lb and buttermilk at $2.95 a quart, I don't think I will bother with using the buttermilk for my cooking.
May be buttermilk will be good if you cook chciken to 212F. I am not about to do that test.
However, as with any experiment, nothing is confirmed until the same results are duplicated by others.