Sourdough baking
While I love cooking with MSG, I'd be skeptical of putting it in bread. It sounds like it had the effect I'd expect and while I don't think I need an umami feeling outta my bread, I bet the magic ratio would mean the bread simply tastes more full-flavored and balanced instead of umami forward.
Really interesting idea, I might have to toy with it myself!
I think it works in a hearty bread like sourdough, or maybe a rye. I don't see it working with a lighter bread very well, but maybe?
I did try doing a few searches for the idea before I started and didn't see anything out there.
Just for an idea of my ratios - my regular loaf is about 500g flour + 275g + 10g salt when it's all mixed (see previous posts for more details.) So with 5g of MSG being too much, I think 3g would give that perfect hint of umami that would just enhance the flavor. Post your results and let's see if we can make Uncle Roger proud.
My big sourdough project around this time of the year is panettone, which I'm thinking probably doesn't need the msg, but I usually make one or two as practice to get the shape right, so maybe I'll be back with a surprisingly full bodied sweet cake 😅