Flemish Kiss dregs in a saison

[nufad]

I made a saison, pitched 3724, and fermented for 3 weeks. The SG was a bit high (1.010), so I decided to add Brett B dregs from a Flemish Kiss (The Commons brewery). For the first week or so, nothing appeared to happen - no airlock activity, very clear beer. After a few more days, the beer became cloudy, and small rafts appeared on the top of the beer. How can I tell if the rafts are mold, bacterial contamination, or Brett? Thanks for your help!