Colinization? Contamination?

BRF Half pint jars. 16 days. B+ Cubensis. Seems like it is taking an incredibly long time to colonize the jar. 4 jars have this snow white spot (some have it at all inoculation point) no larger than a half dollar. Have I botched it and is this some form of contamination? Or is it mycelium and just taking a while to cultivate the jar? Sorry for poor picture quality.