First time using UMAi Drybag and plastic melt

That mold can happen and there are several reasons why – but mostly because of unsafe handling before the meat was placed in the UMAi Dry® bag. Now though it is just on the surface and can be trimmed off. BTW those steaks look beautiful full of rich marbling. As the saying goes “know fat, know taste – no fat, no taste!”

As for in the future 30 days really wasn’t long enough in my opinion…as thick as that sub-primal was it easily could have gone for 45 days with far better results from aging.

Dry aged beef can taste stronger to some and after grilled any smell is gone. The effect of turning red after the salt was added is called blooming and if you salted them way ahead of grilling then unless that salting occurred 4 hours ahead then the salt actually pullout more moisture. If done for 4 hours before the meat will actually draw the moisture back in. BTW this isn’t my opinion, but what test results that Cooks’s Illustrated published.
Ron