Yes, 86 it. The smell can vary from pleasant to just sour to funky-cheesy in my experience. It might not smell good to every nose but never repulsive.

If you are going to use a plant milk I would use one with as absolutely few additives as possible - most soy milk has both sugar and stabilizers and things, so good thinking to ask. If you have one nearby, check an Asian grocery store for plainer soy milks instead of a regular one like the Silk brand for US tastes that expect it to have the mouthfeel and everything like dairy milk. It’s actually not that hard to make delicious fresh soy milk from dry soy beans also. Chris Trump says chick pea milk is the best for LAB, but that’s not available readymade in most areas. I definitely want to try making it sometime.