My point is that even their branded growlers can get ****** dirty. I just don't buy the logic that you're more likely to bring in a clean growler for a fill if it's branded.
I agree the brewer has a vested interest in minimizing risk of filling a growler full of mold or that would otherwise compromise their product.
I would be more receptive to something like not allowing stainless steel growlers since you can't easily see grossly unclean interiors compared to glass.
Either way, to each their own, I just don't get the logic.
Ahhh, I see now. In the case of Holy Mountain and Cloudburst, if you bring in their glassware they swap out a pre-filled, counter-pressure filled growler.
Any brewery that doesn't do pre-fills only and won't let you bring in other branded growlers can **** right off.