From Nate Sears, chef at The Wilt in Chicago:
Last year, at the end of tomato season, I bought about 200 pounds of tomatoes. They were seconds, and dirt-cheap. I had a couple of rough ideas of what I wanted to do with them, but no set plan. I try to not have a set idea with projects like this; when I do, I wind up being disappointed, So I started with a vague plan, and thought I’d just taste it as it went along. First, I salted the tomatoes to kick-start the extraction of the liquid, and threw them in the fridge. From there, I left them on the counter, and let them get that white mold on them and ferment a bit.
One of my former sous chefs made a Sicilian fermented tomato paste. To make that, you salt the tomatoes and pass them through a food mill. You then press them down with a weight to get all the juice out, then air-dry them, then salt them again. It turns into a fermented tomato paste that is amazingly good. Sicilians have done this for centuries; they bottle it up and throw it in olive oil, and have tomato paste for the rest of the year.
I wanted to make it saltier, to preserve it, so we rolled it into logs and dehydrated it. It’s like a tomato bottarga that we can microplane when we want to use. The additional salt adds extra brightness to a dish, and the fermentation gave it a slight funk, but nothing crazy. We increased the acidity and the salt content, so as you microplane it over a dish, you get a really nice pop of flavor instead of a muted thing that isn’t salty enough to make an impact.
I was left with 75 liters of liquid that we had pressed out of the pulp, and didn’t want to throw it out. I tasted it, and it reminded me a little of the fleur de sel vinegar from Rare Tea Cellars, which has been an obsession of mine for a long time. The fleur de sel vinegar is made with seaweed and apple cider vinegar, so I took the inspiration from that to try and make a slightly salty, rich-flavored vinegar with tomato vinegar instead of apple cider vinegar as the base.
I had read about a guy making tomato wine, and I knew that I needed sugar to create alcohol, that would convert into vinegar. We added a Champagne yeast to it, and enough honey to it get the brix level where it would render to about 10 to 12 percent alcohol. We put it into air-locked containers, and let it ferment until all the yeast ate the sugar. We had a salty tomato wine at that point; it smelled and tasted like booze.
From there, we poured it into a Jim Beam bourbon barrel, about four parts tomato wine and one part Bragg’s natural apple cider vinegar with the mother in it. We kept the cap open to let oxygen in, and let it sit for four months, so we got the full conversion to vinegar. Then we capped it, let it coast until this summer, and now we have a nice barrel-aged tomato vinegar. It has a nice sweetness to it, all the oaky, smoky, toasty flavors from the bourbon barrel, plus the salinity from the fleur de sel. You have to be in it for the long haul with projects like this, but it’s worth it
The tomato stuff in the first part of this article reminds me of a Tomato Pesto, Italian, in a jar, that my brother gifted me with. It basically explains how that would have been made--I'd been unable to figure it out.
But wow tomato vinegar. I can make that on my countertop the way I make red wine vinegar. Going to do it!
