Monday, September 10, 2012
Passata from its Italian name: passata di pomodoro, when tomatoes have been "passed" through a sieve to remove seeds and lumps.
I bought a bottle of Del Monte passata this summer and really enjoyed its versatility and "closer to fresh" taste. Unadorned in the bottle, it combines well with any kind of pesto to make a sauce for pizza or pasta. It is thicker than tomato juice or canned tomatoes but not as thick as tomato paste.
Most home processing of tomatoes requires a boiling off of tomatoes to thicken their consistency for sauce. I use a method that involves fire-roasting, drainage, and passing through an Italian-type tomato press to remove the liquid.
Equipment: grill (with cover), tongs, large colander, bowl of sufficient size to hold the colander, masher (optional), spoon for scooping, pot or bowl for pulp transfer if you can't set your sieving device next to your draining setup, Italian tomato press (a large food mill would also work but is more effort), container to hold strained pulp.
Tomatoes and their washing: I use Roma tomatoes for all my preserving. I can obtain a bushel at a time from local grocers or the farmers market in my area. A quarter bushel will yield 6 to 8 pints of passata and 2-3 pints of tomato stock -- yield depends on tomato size and dryness (due to the season's weather). Ripe Romas make the best passata. They also roast quickly and pass through your sieving device easily. I wash the tomatoes in cool water to which I've added a tablespoon or two of vinegar. This will kill mold spores and bacteria on the tomatoes in case you have hold any of the steps over night.
Fire-roasting: I do this on a gas grill. It can be done on a charcoal grill as well -- I imagine there would be more "fire flavour" in the result. You can also roast tomatoes in the oven, but it's too hot where I live to do at the time of tomato harvest. I roast the tomatoes under cover until they are lightly browned on both sides or until they soften and begin to bubble a bit. You don't want them so soft that they fall apart as you lift them from the grill.
Draining: Put the tomatoes in a colander over a bowl. You want them to cool before putting them through your sieving device anyway. If properly cooked, they will flatten on themselves and begin to release some of their juice. Stir to promote this; mashing also helps. I let one batch drain while I load my grill with the next batch.
Sieving: Once the roasted tomatoes have reduced in volume by a quarter to a third, spoon into your sieving device or the vessel to transfer the pulp to your sieving device. Your device will take out the seeds and skins (which can be composted) and leave you with an unseasoned puree of sauce consistency.
Don't throw out the juice you drained. It makes a wonderful gazpacho base or canned tomato stock for winter soups.
Processing: Once you've sieved all your tomatoes, measure the puree to determine how many jars you'll need. Prepare them and heat the puree just to boiling. Put a tablespoon of bottled lemon juice in each pint jar (double it for quarts), fill with puree with at least a half inch head space. Process pints for 35 minutes, quarts for 40.