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Homemade Canned Tomatoes: Passata

The pleasure of eating tomatoes from your own garden all year-round requires the delightfully messy and fun operation called passata, canning cooked pureed tomatoes.

tomato GardenOnce upon the time, there were four seasons and people ate fresh fruits and vegetables only during those few months of the year when produce was ripe. This simple fact is hard for us to imagine nowadays, when so many of us are able to enjoy delicious fruits and vegetables any time of the year. But, for generations and generations, the question of how to extend the life of produce was a matter of great concern for most families. Over the centuries, before industrialization, many inventive ways were developed to preserve food—in the winter months, food could be preserved in snow and ice; caves and outdoor canteens also provided a natural way to store foods in cool temperatures; and the use of salt, sugar, ashes, air curing, air drying, and other natural methods for preserving food were used for centuries.

In the early 19th-century, however, there was an urgent incentive to find ways to preserve food on a massive scale: the constant warfare between the large European nations created a great need to feed an enormous number of troops. In France, rewards were offered in an effort to encourage inventors to come up with some ideas. The approach succeeded: a method for preserving food inside glass jars was found to be effective as long as the jars were sealed well; later, Louis Pasteur scientifically proved the importance of heat in food preservation. By the mid-19th century, metal cans began to replace the glass jars, which were fragile and costly. Since this method of canning was invented in England thirty years before the appearance of the first can opener, soldiers and civilians alike were obliged to open the metal cans with bayonets and knives—which must have caused quite a number of nasty accidents! 

At this same time, in Italy—especially in the central southern regions—pasta was becoming the staple food for most families; and of course, where there is pasta, there is the desire for tomatoes … all year-round. During the Kingdom of the Two Sicilies (from 1816-1861), when France occupied most of southern Italy, it’s very likely that the French passed their newly discovered methods for preserving food—most importantly, tomatoes—to the Neapolitans. Today, it’s hard to imagine what life in Italy would be like if for ten months of the year it were not possible to eatpasta with tomato sauce. 

passata pureed tomatoes homemadeAfter the introduction of industrial methods—and the invention of the can opener!— the availability of canned tomatoes certainly reduced the importance of the Italian tradition of canning tomatoes at home—a time-honored family ritual known as “far la passata.” Yet, the pleasure of eating tomatoes from your own garden (or your local farmer’s) all year-round has motivated generations of Italian families to gather for an entire day—sometimes two or three—to undertake the rather complicated, delightfully messy and fun operation called passata, which means literally “to pass through” (as the tomatoes are passed through a hand-held vegetable mill). In Italy, children are always involved and their delight in the process is half the fun. By the way, it’s largely because of children that the passata is still so popular in Italy; children are notoriously picky about the seeds and skin of tomatoes, and the passata removes them. (Also, it should be noted that in Italy, usually the tomatoes are not first peeled before they are passed through the mill; in the United States tomatoes are often preserved peeled and uncooked. This method requires the addition of lemon juice and sugar—though the latter is admissible, lemon juice is certainly not a desirable ingredient for tomatoes that are destined to be used in sauces.) 

HOW TO: Traditional Passata (cooked, pureed tomatoes)

Equipment required:

  • Several canning jars (able to withstand boiling temperatures) with new lids; all must be cleaned and sterilized
  • A very large pot to sbollentare (that is, to quickly boil) the tomatoes
  • Another pot large enough to contain the passati (pureed) tomatoes
  • A vegetable mill (passaverdura)—manual or electric
  • A pot large enough to hold the filled jars
  • A canning funnel used to fill the jars 
  • Jar lifters (which are special tongs that will be needed to pull the jars out of boiling water, if you do more than one batch) 
  • Tablecloth or kitchen towels in which to line the bottom of the pot so the jars avoid breakage

Ingredients:

  • Tomatoes of the best variety (such as, San Marzano–type, Pachino, Cilegino, Roma, etc.)
  • Fresh basil (optional)
  • Coarse salt

Preparation:

roma tomatoes ready for making passataThe way you organize your work will depend on the quantity of tomatoes you’re preserving, the available helpers you have on hand, the number of large pots you have for boiling the jars and lids and for cooking the tomatoes. But no matter how you proceed later, first you must clean, boil and sterilize, and then dry your jars and lids.

If it’s your first experience canning tomatoes, it’s recommended that you start with a small amount of tomatoes. As we say in Italy: bisogna farsi la mano, which literally means “you need to have the hand first”—in other words, it’s important to first get a knack for the process.

The ratio of tomatoes to passata (the cooked, pureed tomatoes) is about 2-2 1/2 to 1; that is, to make 10 pounds of passata, you’ll need 20 to 25 pounds of tomatoes. It’s very important to use the best-tasting, ripe tomatoes you can find—those that are especially suitable for sauce, such as those listed in the ingredients above. (Watery tomatoes are not the most desirable for making homemade passata. If your tomatoes are watery you will need to cook the passata before jarring to thicken.) 

cooked tomatoesWash the tomatoes and remove any bad or unripe parts with a sharp knife. Cut the tomatoes in quarters, and fill the pot with all the tomatoes you can possibly fit; you may have to do it in more than one batch. (NOTE: no water is added to the pot here, just tomatoes in a pot). Add 6 or 7 teaspoons of salt for every 20 pounds of tomatoes. Cover the pot until the tomatoes start to boil, then uncover and let simmer for about 15 minutes—stirring once in a while—or cooking until the tomatoes are sfatti (that is, “breaking up” or “coming apart”) and the water has reduced. You want the tomatoes to break up so that the precious pulp comes easily from the skins when it passed through the vegetable mill. 

Now you must do the actual passata: Remove the cooked tomatoes from the pot with a ladle and pour them into the vegetable mill, which should be placed over a large pot (without flame). Use a filter specifically for tomatoes—that is, with holes that are small enough to prevent the tomato seeds from passing through, but not overly small. To make the filtering process easier, here’s a helpful hint: After four or five turns in a clockwise direction, turn the handle back one full revolution in the opposite direction. By doing this, you’ll unclog the holes, allowing most of the passata through. Even still, once in a while you’ll have to remove the filter and shake out the residue of tomato skins and seeds; otherwise, the residue will accumulate and it will take much longer to do the job. There are also electric and/or professional vegetable mill versions. If you use an electric mill, be sure to follow the instructions carefully. After you have passed all the tomatoes, take the discards (seeds and skins) and run them through the mill once more…there is a lot of good pulp still stuck on the skins. 

cooking the tomatoes brieflyNote: If your passata is not dense or thick enough, you can put the pot of passata on the stove and let it reduce; the risk of course is that the passata will lose its fresh tomato taste. One way to avoid the risk of making a “too watery” passata is to cut the tomatoes in half and then squeeze them in your hand into a bowl before cooking; this will get rid of most of the water and seeds. This procedure is often done by professional cooks to quickly obtain the pulp of the tomato in order to work with it in a quicker and cleaner way.

When your passata is ready, you can start to fill the jars. Lay three or four leaves of clean basil on the bottom of each jar and add the passata through a canning funnel, filling the jar up to about an inch from the top. Close each jar well, making sure that every one is perfectly sealed. Then, lay a tablecloth or kitchen towels in the bottom of the pot you are going to boil the jars in to avoid breakage. Put the jars in a large pot, and then fill the pot with lukewarm water—do not use cold water; if the jars are hot, they will easily break. There should be enough water in the pot so that all the jars are completely immersed in water, with still a couple of inches of water at the top. Then simmer at a low boil for 45 minutes; add some boiling water if it reduces too much. If this is your only batch, allow the jars to remain in the water after the boiling bath until they are cold enough to pull out; otherwise, use the special tongs and repeat the operation until you are done. Let the jars chill down and then store them in a dark and cool place. The tomatoes will be preserved for a year.

Pomodoro a pezzi passing the cooked tomatoes to make puree

If you prefer chunks or whole tomatoes to a passed sauce, there is an alternative method for preserving tomatoes. Though not technically a passata because it is done without the use of a vegetable mill, there are some real advantages to the following method: First make a quick, shallow cross with a knife on the tomato and then scottate (which means “blanche”) the tomatoes in boiling water for just a minute; then immerse in cold water in order to peel them. The skin should peel off very easily. Cut the peeled tomatoes in halves, and then remove any excess water and seeds by hand.

Cut the tomatoes into chunks and fill the sterilized jars. Close each jar well, making sure that every one is perfectly sealed. Then, lay a tablecloth or kitchen towels in the bottom of the pot you are going to boil the jars in to avoid breakage. Put the jars in a large pot, and then fill the pot with lukewarm water—do not use cold water. There should be enough water in the pot so that all the jars are completely immersed in water, with still a couple of inches of water at the top. Then simmer at a low boil for 45 minutes; add some boiling water if it reduces too much. If this is your only batch, allow the jars to remain in the water after the boiling bath until they are cold enough to pull out; otherwise, use the special tongs and repeat the operation until you are done. Let the jars chill down and then store them in a dark and cool place. The tomatoes will be preserved for a year.

Using this method, you cook the tomatoes a much shorter amount of time, get a fresher tomato taste, and obtain chunkier preserved tomatoes. If you prefer the entire whole peeled tomato, just eliminate the steps of halving and cleaning the tomatoes before you place them in the jar, but note that your jar may contain more water later after settling.