Hybrid Garum

Waste not, want not, part infinity

This is a fun one. If you watched the Chefs’ Corner presentation during Kojicon this year, I made a pint of steel-cut oat amazake as part of my demonstration. That sat around in the kitchen for a while, and I totally meant to make something with it but didn’t quite get around to it. Then I bought a lovely whole mackerel for dinner, and after taking it apart it occurred to me that its head, tail, and skeleton weren’t enough to make much of anything on their own (besides a small pot of broth), it might be fun to toss them in the matured (read: sour) oat amazake and see what happened.

I chopped them up, put them in a quart jar with the amazake and enough water to nearly fill the jar, added 10% of the total weight in salt, and put the jar in a pot with the circulator (and a couple of other jars with different koji ferments) and let it go for about a week. Note that if you’re not going to accelerate a fish ferment like this by heating it to 140˚F/60˚C you should add at least 15% salt by weight to be safe at ambient temperatures.

The result is not as deep and dank as full-on fish sauce, but it’s got a wonderfully transparent fishiness that begs to be deployed as an enhancement to pristine seafood—I’ll be bringing it to the beach with me later this summer. The solids are in the dehydrator, and I have something really fun (and clever, if I do say so myself) planned for those once they’re ready.

The takeaway from this is twofold: first, amazakes that lose their sweetness still have plenty of enzymatic power to give (and a nice acetic sourness too) and second, even the trimmings from one small fish can provide a ton of utility. I ended up with a full half liter bottle of the liquid, which should last well into the fall.