10 pounds of tomatoes = 12 fl oz of tomato paste.
Or conserva as the Italians call it.
Three years ago, I was using Saveur Magazine’s recipe and Italian-type tomatoes to make tomato paste. I have since learned to use any tomatoes to make tomato paste, not the just the processing type (although they are unquestionably preferable), because you know, I do plant a lot of tomatoes (big, small & medium, and giant) and in good years, we have lots of fruit. Since the beefsteak tomatoes have a lot more juice, the trick is to get the water out of them. I steam them: I know, it sound contradictory, but it works. I also found that I’d rather use a lower temperature and more time, to avoid burning the paste – which is extremely easy to do toward the end.
The paste does not take a lot of active time (except for the food-mill part) but requires you to be around so you can stir it every hour at the beginning of the oven time, more often as the puree changes to past.
And of course, you could spread the work over a few days: Steam to tomatoes on Day 1 (refrigerate), pass through the food mill on Day 2 (refrigerate) and bake on Day 3.
Homemade Tomato Paste
Yield: About 2 cups
· 10-12 lbs. red tomatoes.
· a few tablespoons of olive oil
Halve tomatoes and put them in a non-reactive steamer with a little water at the bottom. I use a granite-ware pasta pot with the pasta insert: the tomatoes go in the insert. Steam until tomatoes are very soft and collapse (about 20 minutes). Let cool some. Remove insert, and discard water accumulated in the pot(it should be clear, not red). Put the insert back and let drip a couple of hours. You’ll collect more water, fairly clear still. Discard the water.
Put tomatoes in a food mill, with the finest plate possible. Let drip for 15 minutes without turning the handle. At this point you should have thin juice: I pour the juice away for another use (drink it, cook rice or couscous etc).
Now start cranking the handle and process the tomatoes getting as much of the pulp as possible. And I mean it, when you think you are done turning the handle, turn some more: there is a lot in the skins! Oil two large rimmed non-reactive baking sheets or oven-safe pans with a little olive oil. I generally use at least 2 pans: my oven pan and a large Le Creuset pan (and stick something else in the oven like ribs so as not to waste any space) Heat oven to 225° F (105-110C) Spread tomato purée evenly in pan(s). The thinner the layer of puree, the more you are going to have to watch and stir to avoid burning. Bake, stirring the purée occasionally every hour, until a lot of the water evaporates and the puree has noticeably thickened – maybe 3 hours.
Then set your timer to check it every 30 minutes: when you stir, use a spatula to really push the paste together toward the center of the pan, being careful not to leave much residue on the pan. Any tomato smears will burn.
Keep baking until you are satisfied with the thickness of the paste. This may take another 4 hours (or less depending on how well you remove water initially). Toward the end, check every 15 minutes, lowering temperature to 200 F (95C) if needed.
Back in 2008, reader Tim mentioned that he used small muffin pans lined with tiny muffin paper cups to shape and freeze the paste. That was brilliant and that is what I do now. Once the paste is frozen, I pop out the paste “muffins” and stack them in another freezer container.
It works wonderfully. One bushel of tomatoes (50 pounds) get transformed into 4 or 5 pints of this brick-red fragrant rich paste. Magic! (Magic when it is used to enrich tomato sauce or pizza too!)