Stabilizers

We are likely going to add potassium sorbate and metabisulfate to a flanders red we made and are blending, and we have decided to stabilize, re-yeast with champagne yeast and bottle-condition.

Do stabilizers need to be added when the beer is cold for them to work, and would there be any benefit to cold crashing before stabilizing?

I have a little experience using it with wine, and I can’t imagine it would be much different with beer. Take it with a grain of salt, though. The k-sorbate works best when there is as little yeast as possible in solution, as it prevents reproduction. With wine, using it when it is completely clear is the best bet, as it will prevent the yeast that are still suspended from reproducing and fermenting whatever sugars you add. From this sense, I would think it would follow that cold crashing would be a good idea?

It might be difficult to carbonate after adding k-sorbate. Again, this is my experience with wine, which might not necessarily have the same effect in a sour beer…