Ive piched the 530 yeast as cold as 62 deg with no issues. They can be finiky if there is variation in temp swings and they also can get quite lazy when it comes to long chain sugars. While I do enjoy the sour beers as well Im not for pitching brett unless thats what Im going to target. Otherwise good luck.

pizzle: I don't recall saying the FG is 15.6 Brix. And you can determine the FG using a refractometer. You just need the OG (which I have).

Petedadink: I don't understand your post. I tried pitching champagne yeast when my original yeast pooped out, but that didn't work. That's why I pitched the bugs. My most recent question was about naturally carbonating.

I have used 530 several times and it did stall once on a 1.080 beer but woke up a week later an finished at 1.010. YMMV

My current question is about how long I should let it sit with the Brett B/what FG should I go with and how do I naturally carb this beer. I don't care about 530 anymore.

The brett should continue to work as long as its getting some occasional O2 (though the airlock, carboy cap, etc.). I would let it go until you get to your original target FG. Then add sugar and yeast for priming. The new yeast shouldn't have a problem consuming the simple sugars. You may want to try to carbonate a couple bottles as an experiment to make sure it will work for your beer before adding the additional sugar to the whole batch.

Thanks Quin.

It seems like the bacteria would continue consuming sugars if I bottled such that the longer bottle sit, the more carbonated they become. If we're talking about an intended non-bug FG of 1.024, it's got A LOT more sugar that it can eat. I'd imagine there's be a legitimate concern for bottle bombs.

Would pasteurizing be the best option here?

The brett is a yeast though, not bacteria. From my experience, they will only keep working with some oxygen. I added some to a 1.064 Maibock that finished at 1.020. The beer was uncarbonated going into the keg. It only brought it down to 1.016 during 6 months at room temperature. The beer had a great brett character, and tasted very dry even though the FG was still kinda high. I've since done this a couple times and with similar results each time.

Your batch may be different, though. That's why I would try a couple bottle to see what happens.

Thanks Quin. I think I'll actually force carb after it drops a down to 1.026 or so. That should be easiest.