I am going to attempt making mozzarella for the first time and just learned rennet is not vegetarian. Has anyone used veggie rennet?

veggie rennet, or microbial rennet works great! Enjoy your mozz!

Yes, I've used veggie rennet, and it worked well. I recommend wearing thin neoprene gloves for stretching the cheese. The curd really needs to get pretty hot to stretch well, and unless you have asbestos hands it's hard to handle w/o gloves.