I've been happy with my conical fermenter, though I've seen an unsettling trend in the first 3 batches I made in it. The upper part of the dried kräusen is black, which I assume is mold. I've been extra vigilant about keeping things clean, and limited the potential oxygen exposure. For the last batch, I didn't even draw any yeast or trub in order to avoid sucking in oxygen. I assumed there would be enough CO2 to prevent mold from forming. The last batch also had an addition of oak chips that where thoroughly boiled for 20 minutes.
Any thoughts on what this black stuff is or why it keeps on coming back?
Any thoughts on what this black stuff is or why it keeps on coming back?