This summer I got my hands on a case of fresh roma tomatoes and ventured into this ferment. I’d wanted to try it for a good while, and when Sandor’s latest book came out, I decided to get to it. I followed the recipe as is on page 117 of The Art of Fermentation. . I did this in July and with warm temperatures, the ferment went quick.
First I halved the tomatoes, added salt and stirred with my hands. I did not attempt to get anything submerged at this stage. After 1 day, I could stir it down to where all the halves were submerged. (I have fermented tomatoes before for the juice [to make bloody marys], and I knew that if I let this go even a day too long the bacteria would strip and all the pulp from the skins, leaving me only the skins and a thin slurry of what was the pulp at the bottom of the vessel- and this time I wanted the pulp.)
I stirred two or three times a day. Each morning a black spidery-looking mold would have formed atop the floating tomato halves. I would quickly stir this into the mix, and get everything coated in the bubbling liquid. After a couple days, the Kahm yeast would try to get organized in pools of juice around the floating halves, but again, a quick stir would dispel them. Once the rapid bubbling was over, and while there was still pulp on the skins, I strained off what juice there was (about 2 gallons), and processed what remained of the halves, separating the skins/seeds from the pulp. Here are the tomato halves ready to strain.
And here are the tomatoes being processed in a slick little device I borrowed from the neighbor. Tomatoes in the hopper upper right, paste into the hotel pan on the left. and skins/seeds into the container lower right.
I then put the pulp in a cotton bag and let it hang over night, twisting it to get as much juice out as I could. At no time did a thick layer of mold appear on the cloth, only a very thin slight white bloom, likely yeast, and I saw no need to attempt to remove it by scraping it with a spoon.
I put the juice in a vessel, and within a couple hours a lovely rich layer of Kahm yeast had formed. Since I know this can influence the flavor, I poured the juice into glass jugs with airlocks to keep out the oxygen. I ended up with 2.5 gallons of juice that are now fermenting for next year’s cocktails.
Next, I took the ball of paste that had dripped overnight and placed it into a clean cotton cloth and tied the corners. I set this to press inside a stainless steel hotel pan with a concrete block on top, further squeezing out more liquid. I put dry towels beneath and on top of the wrapped ball of paste, and changed these a couple times a day as they wicked out juice from the paste.
After 3 days I removed the paste and marveled at the color. Gorgeous! I added salt, 25% by weight, and kneaded it into the paste. But this proved way too much salt for my palette. If I use the paste now in a quantity where I obtain the tomato flavor I desire, it is inedible because of the high salt content. But is it ever beautiful? Beauty has its limits though, so, frustrated, I formed some of the paste into 1-inch balls and cubes and dehydrated them. I now use these to grate the dried tomato paste over foods I want to salt, and beauty comes right along with it. The red color looks spectacular on poached eggs, roasted chicken or steamed cabbage. So, I use it as I would salt, with a little elegance. The final yield was 1 pint of paste.