Keg was connected via pipe and mechanical pump to a Create water tank to receive water. Keg was mined, entire game crashed. The keg item was lost in the crash :(

Less important, but still relevant to Create:
When connected to a fluid pipe and mechanical pump intended to move brewed liquid out of the keg, a tankard of beer isn't recognized as a valid liquid container by Create, so a smart pipe can't filter what liquid it pulls. Create allegedly uses any liquid container as a filter, so maybe there's a tag that is missing on the tankard of beer.
Again, that one is not as pressing, and I can clarify if needed. My dreams of building an automated Create brewery will hopefully be fulfilled one day lol.

Having a ton of fun w this mod otherwise :)

The described crash is a known issue of Create that applies almost all fluid containers and will be fixed in next Create release.

The other minor issue can be fixed by Create: Central Kitchen (Yeah I'm promoting my mod ;))

As mentioned by Raymond, it's a Create bug.

This would also require major rewrites on our end to turn the tankard into a fluid container. I may do this in the future but there'd be many things to figure out there.