Excuse almost limitless ignorance - first kit brew. Brewing the Woodforde's Wherry. Been fermenting for 7 days. There;s a blotchy layer over the top, but is this fermenting? Been at about 18 degrees. Trying to warm it up a bit... Struggling to attach photo Any comments gratefully received. Also, in your experience would you add 1/2 tsp priming sugar per bottle, or 1tsp? I've seen references to both online. Kit says 1tsp. Cheers.