lactofermenting blueberries have hardly produced any liquid - is this safe?

Question

I've begun a batch of lactofermented blueberries, following the recipe in The Noma Guide To Fermentation. I mixed the salt and blueberries, and poured them into jar, where they've been sitting for a little over a couple days under a weight.

But, the blueberries have hardly released enough liquid to cover the batch. My experience with pickles tells me to submerge the cukes under brine, lest they spoil.

I'm obviously a beginner here. This strikes me as being unsafe; I picked out one blueberry at the top that already went moldy.

Should the blueberries be submerged?

Answer 1

They should be submerged. Lactofermentation is done anaerobically - under the brine. If it is in contact with air, mold starts to develop (mold is aerobic). Also yeast has an aerobic mode, where it multiplies, so the berries might become slightly alcoholic.

Either put brine on top of the next batch, or squish/bruise some of the berries.