Back here in Northern California, I’ve been canning tomato puree for a few years. I got started with the classic Ball waterbath canning kit — the giant pot, the the jar lifter tongs and lid magnet and weird little headspace measuring stick,also useful for releasing bubbles out of the jars before you boil the living bejesus out of them. The impulse wasn’t some hippy-crunchy survivalist meme. It was the hippy-crunchy “avoid the endocrine-disruptor BPA in commercial can liners.” The fact that home-canned tomato puree — the basis for every superb pasta sauce — just tasted so much better and fresher than the overcooked, stale and chemical-tasting stuff in grocery cans was simply a benefit to the process.
Well, in order to get a few quarts of good, thick tomato puree to can, you’ve got to go big or go home.
At this point, I’m used to the amount of work it takes to reduce a perfect tomato into a perfect quart of tomato puree. I’ve had to learn how to avoid separation and suctioning through the lid and overcooking the tomatoes in the thickening-simmerdown process before the canning procedure. (DO NOT LET IT BOIL, for the love of Pete.) And you also need a version of what Alchemist Natty and I call “The Machine.”
Once the tomatoes are soft enough through a bit of sweating in a big-ass pot, you can pop them into The Machine and it strips out seeds and skins with relatively little effort and a lot of speed. Then it’s a matter of sloooowly simmering down any extra water out of the puree (you’ve already gotten rid of a great deal through the sweating process) and setting them up into jars for canning.
After that, the boil-the-bunny process begins. Timing is everything.
But what do you do if you have a ton of a tomato varietal that’s not exactly prime for puree-making? Well, just like everyone else, I get a cup of coffee and go to the web. My friend Kris is a tomato-growing goddess, as well as a superbly skilled cook, griller, and smoker (check out her blog), and she provided me with a few pounds of utterly lovely cherry tomatoes. I owe her some Anaheims and hot peppers, which have not as yet been particularly cooperative, but I have threatened them and we should see some production in the near future.
A bit of bounding around the Web found a recipe for “Oven Roasted Cherry Tomato Paste.” Paste was something I hadn’t tried yet, so the circumstances seemed ideal. I prepared everything according to directions — it’s a satisfyingly OCD process — and got ready to rumble.
There actually ended up to be a lot more of them, turning the whole process into a kind of Tetris game.
They’re roasted until they wrinkle and dry a bit on the rims, but take them out before they collapse into themselves and turn into tomato goo. Then you pop them into a blender (or food processor, for you evolved folks). I used my ancient and almost museum-worthy Osterizer.
Now here is what I found was the key. After blending, the recipe author did not strain out the skins and seeds that had remained unblended, so I didn’t. The puree then went into a pot for a very slow simmer, cooking for over an hour, stirring frequently as the puree reduced and folding it into itself. Once the paste clings to a spoon held sideways without falling off, you’re done.
But at testing, I found that the unblended skins and seeds gave the paste an unpleasant texture. Perhaps a Vitamix could have taken care of this problem, as opposed to my anachronistic Osterizer. Regardless, it wasn’t what I thought of as paste. Hard, angry little bits were getting stuck in my teeth. It had to be fixed.
I added a dollop of water to the paste, stirred it back up into a puree, and strained it through the magical Chinoise. This is the material that was left behind.
Then back into the pot for another simmer down, stirring, folding.
I think the double-simmering did no good for the paste taste and texture, and it certainly reduced it to the point of absurdity. In the end, I had about as much as a single can of tomato paste from the store — probably a little less.
That’s probably about enough for one batch of tomato sauce. You’d probably get more out of the recipe if you strain BEFORE reducing, instead of repeating the process twice, like I did. I can’t judge the taste properly because of the double cooking, but it doesn’t have the dark, smokey, weirdish flavor of grocery tomato paste even with my bumbling around.
But honestly, it’s all a matter of experimentation. And where would us alchemists be without that?