mildew

I know nothing, this is my first time growing vines to make wine. I should have sprayed earlier. I have just sprayed for the first time against Downy Mildew. I noted a small problem on some of my vine leaves in one vineyard some weeks ago, and never thought anything of it. I went down to the...

So I have two gallons of the same batch of grapefruit wine. One has developed a peculiar white ring at the top of the wine where it terminates in the neck of the jug. Anyone seen this before? Should I be concerned with it? Is it just some residual fermentation? I ask because the other is clear...