Pressed my grapes (Zinfandel) last Saturday and are now in Demjohns fermenting nicely, my only concern is the stuff that has floated to the top. Is this normal, there is no foul smell I'm waiting for the fermentation to stop so I can rack the wine. I usuallwait up to 60 days to do my first racking, but I'm thinking I need to do this a lot sooner. Any thoughts or advice