I was shocked to see that the barley wine had split into 3 layers. The upper layer was translucent and fermenting. The middle layer was a layer of yeast, like a yeast cake. The bottom was a thick dark layer with no fermentation activity at all. Tried to swirl the fermenter to mix the layers but nothing happened. It was like trying to mix oil and water. I started to do some research what it could be. I found out that it was called wort stratification. When different sugars get layered. According to what I found, the cause is that the wort isn’t mixed thoroughly. I use an electric hand whisk to aerate the wort. I whisk it til the wort has a frothy head, maybe it’s not enough. I’ll go back to the good old shake the fermenter. I found two solutions to the problem; Either shake the fermenter or leave it be, to let the yeast to take care of it on their own.
In the morning, when I went to check on how the fermentation was getting on. The layers were gone. The yeast must have eaten its’ way through the thick layer. The scent coming out of the airlock are caramel and banana candy, yummy. Moral of the story, shake the fermenter don’t use an electric hand whisk.