OK! I don't think I ever reported back on my oat milk so here's what I tried:

100g oats
17g miyoko's vegan salt butter
50g garbanzo bean juice
15g sugar
666g water

Blended together and strained through a cloth

It came out pretty well! It separates out quite a bit but stays more or less in suspension with some vigorous stirring and/or shaking

Taste is not bad although I think I could dial it in, I don't think I need sugar at all if I try using amylase, which is what I suspect oatly uses

I don't think I know a lot of bio/enzyme people here or otherwise but I wonder if you @compostablespork are in a close enough field to point me in the right direction.

Does the amylase itself have a flavor? I imagine it tasting like spit, which is to say that you taste it all day long so it may as well be neutral or background noise.

Does it get "used up" when it converts starch to glucose? Like, does the final product have any amylase in it if it's the limiting reagent?

@compostablespork Is there a good place to buy it? I did a little searching but aside from not wanting to buy things from amazon to begin with, it seems like a lot of them are like 96% dextrose, which kind of defeats the purpose

Does it degrade over time? If I were to make like a 10% solution would I need to watch it for spoilage? Any idea what that would look like? I ask mainly because I am seeing concentrates but dosing by drops just seems so inaccurate, and I could do a two step thing?

@compostablespork Is it ever (or maybe even always) animal derived? It would kind of defeat the purpose of using it to make a milk substitute if so

@pagrus @compostablespork not a scientist but bakers (and brewers) will sometimes use diastatic malts for a natural source of amylase so that might be one option?

my understanding is that pure amylase often comes from pigs which is one of the reasons to prefer malts but [citation needed]

@Satsuma @compostablespork Ah yeah if it came from pigs that would be a no go for me. This one looks promising https://www.homesciencetools.com/product/amylase-enzyme-30-ml/