I have a beer (braggot) in primary that has a high percentage of lactose in it. It has developed a white film on the top of the beer after about 4 weeks. I don't think it's an infection at all, it looks a lot like cream floating on the top.
Has anyone experienced this when using lactose?
1 gallon batch
4 oz of lactose
1 pound malted oats
1 pound honey
Oats were mashed and sparged, then the lactose and honey were added to the 100 degree wort.
No temperature control on the fermentation.