I brewed a porter, fermented for 10 days and transfered to secondary. I spilt off 1 gallon into a gallon glass carboy (brand new, rinsed with hot water 3 times and sprayed with starsan). Also added 7 teaspoons of raspberry extract from a new bottle. Six hours later, there is a white/yellow thick foam on the top. The other part of the batch in the 5 gal carboy looks fine. Any ideas if this is infected and can it happen that quick?