Blueberry addition to secondary question

[LightningInABottle]

I racked into the secondary last night and I added some blueberries. I have read that blueberries expand and I need to leave head room. When I added the blueberries they sank to the bottom and they remained there over night. The berries went through 3 freeze thaw cycles and there was a lot of juice in the freezer bag. I cut a small hole in the freezer bag and let the juice drain then I smooshed the rest as best I could. It was sort of like using a pastry frosting bag. There appears to be room for 2 more pounds. How long should I give the blueberries to expand before topping it off with 2 more pounds?

 

[MedsenFey]

Uhhh, if the berries were to expand, it would be because they are absorbing liquid from the mead they are sitting in so total volume isn't going to change. In your case, the berries have been smushed and aren't going to expand. If active fermentation picks up again after adding fruit, leaving some headspace is a good idea, but it sounds like this batch is quiet enough that headspace may not be an issue (if you tell us the SG, current gravity and yeast strain used, folks can say more).

Medsen

 

[LightningInABottle]

Starting gravity is in my notes @ home, but here are some more details.
18lbs of honey
4 gallons of water
8lbs of blueberries in primary
D47 yeast
FG 0.096

6lbs of blueberries in secondary. Possibly room for 2lbs.

 

[MedsenFey]

I don't think you have much to worry about. The yeast are pretty close to their alcohol tolerance so I don't think you're likely to get vigorous fermentation and you can go ahead and add the other 2 pounds.