Canning Tomatoes For Passata

Create a natural, flavorful tomato passata to enjoy all year long by canning your garden tomatoes. Passata is perfect for pasta sauces, pizza sauces, soups, stews and a myriad of Italian recipes. Canning homemade tomato passata is definitely a little messy and a little time, but definitely worth it.

Imagine a world where you can only enjoy fruits and vegetables for a few months out of the year.

Fortunately for us, advancements in preservation and travel have led to extended shelf life and the trade for off-season goods. Because of this, we can buy strawberries in December and tomatoes in February. Before these modern innovations and industrialization, many inventive ways were developed to preserve food. In the winter months, snow and ice was used. Caves and outdoor canteens were used to store foods in cool temperatures. Salt, sugar, ashes, air curing and air drying were some of the other natural methods used to preserve foods.

The Beginnings of Canning

In the early 19th-century, 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 good ideas. This approach succeeded, resulting in the method that we refer to today as canning—or preserving food inside of glass jars. This was found to be effective as long as the jars were sealed well.

It was only later that Louis Pasteur added to this innovation with heat. Pasteur (hint: “pasteurization”) and his science had proven 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 30 years before the appearance of the first can opener, soldiers and civilians alike were obliged to open the metal cans with bayonets and knives—not such an efficient nor safe way to open cans, as you may imagine.

In Italy: Along Came Pasta

In Italy during this time—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 need for tomatoes. 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 on their newly discovered methods for food preservation—most importantly, for tomatoes—to the Neapolitans. Today, it’s hard to imagine what life in Italy would be like if we could only enjoy pasta with tomato sauce for two months out of the year. Just think, something like the highly prized San Marzano tomato might be worth its weight in gold!

The Act of Passata

After the introduction of industrial methods and the invention of the can opener, tomatoes were more widely available. Because of this, canning tomatoes at home—a time-honored family tradition known as far la passata—wasn’t so efficient or necessary anymore. Still, savoring your own garden’s tomatoes (and those of local farmers’) all year long has motivated generations of families to carry on the ritual, gathering for an entire day or two to undertake the task of passata. Passata literally means “to pass through,” a reference to the hand-held vegetable mill that the tomatoes are passed through.

In Italy, children are always involved in making tomato purée. Their delight in the process is half of the fun. Did you know that it’s largely because of children that passata is still so popular in Italy? Children are notoriously picky about the seeds and the skin of tomatoes, and the passata removes them, of course.

It should be noted that, in Italy, the tomatoes are not first peeled before they are passed through the mill. In the U.S., tomatoes are often preserved once they are peeled and uncooked. This method requires the addition of lemon juice and sugar—though the latter is admissible, lemon juice is not a desirable ingredient for tomatoes that are destined for sauce making.

Why Can Your Produce

These days, canning has become somewhat of an art form.

On the practical side, for those who grow food gardens, canning is a way to preserve what you’ve grown—especially if you’re prone to overplanting. It helps to reduce waste, since we can only eat so many fruits and veggies in a short period of time (before they go bad). Canning allows you to preserve these garden-grown goods until you can enjoy them. Besides, food just tastes better when you make it yourself from fresh ingredients—don’t you think?

How To Create a Traditional Italian Passata (Cooked, Puréed Tomatoes)

Want to know how to make passata? If you’re looking to can your own tomatoes and create a sauce-ready passata, we want to share some step-by-step instructions and passata tips for you.

You will need:

Glass canning jars with new lids and screw bands. All should be cleaned and sterilized.
3 large pots: one to boil the tomatoes, one to contain the puréed tomatoes and another to boil the cans.
A manual or electric vegetable mill, or a food processor and sieve.
A canning funnel used to fill the jars.
Jar lifters or large tongs.
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, Roma, etc.)
Fresh basil leaves (optional)
Coarse salt

Directions:

1. Clean, sterilize and dry the jars and lids. Just because the jars are washed doesn’t mean they are free of microbes and germs. Using the jar lifters, plunge your glass jars into a pot of boiling water. Keep them in there for about 15 minutes or until you’re ready to use. Sterilize the lids in a separate bowl. Scoop in a few cups of boiling water. Dry jars and lids well before use.

2. Ready the tomatoes. Wash and dry the tomatoes well. Using a sharp knife, remove any undesirable and unripe parts of the tomato. Cut them in quarters.

3. Cook down. Fill a large pot with as many tomatoes as you can fit. You may have to do more than one batch. Add salt to the pot—no water! Add 6 to 7 teaspoons of salt for every 20 pounds of tomatoes. Cover the pot with a lid and place the tomatoes over medium-high heat. Once they begin to boil, uncover the pot and set to simmer for about 15 minutes or until the tomatoes begin to break apart and the water is reduced. Stir occasionally. The goal is for the flesh of the tomatoes to come apart easily from the skins when passed through the vegetable mill.

4. Mill the tomatoes. Place the vegetable mill on top of another large pot. Select a vegetable mill filter specifically for tomatoes. The holes should be small enough to catch the seeds. Using a ladle, transfer the cooked tomatoes from the pot to the vegetable mill. To make the filtering process easier, here’s a helpful hint: after 4 or 5 turns in a clockwise direction, turn the handle back one full revolution in the opposite direction. By doing this, you can unclog the holes, allowing the passata to pass through more efficiently. Even still, once in a while, remove the filter and shake out the residue of tomato skins and seeds. 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.

5. Pass through once more. 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 to the skins!

6. Fill the jars. Once the passata is ready, begin to fill the jars. Place 3 to 4 fresh clean basil leaves on the bottom of each jar (optional). Using the canning funnel, fill each jar leaving about 1 inch of room from the top. Close each jar and secure with lid screws. They must be sealed well.

7. Seal jars. Line the bottom of a large pot with a folded kitchen towel. Arrange the jars in the pot, then fill with lukewarm water. (Be sure not to use cold water. If the jars are still hot from cleaning, they will break.) There should be enough water in the pot so that all the jars are completely immersed. Heats jars at a low boil for 45 minutes. Add boiling water to the pot if water level reduces too much.

8. Finish. If you are only canning one batch, allow the jars to remain in the water once you remove from the heat. Once they are cool enough, pull them out. Otherwise, use jar lifters or large tongs to remove the jars from the boiling bath. Repeat process with remaining jars. Once the jars are room temperature and chilled, store in a cool, dry place for up to a year.

Tips:

Start small. 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 translates to “you need to have the hand first.” This means that it is important to learn the process first (before undertaking too much).
Learn the ratio. The ratio of tomatoes to the finished passata (the cooked, puréed tomatoes) is about 2 1/2 to 1. For example, to make 10 pounds of passata, you will need 20 to 25 pounds of tomatoes.
Only the best. It’s very important to use the best-tasting ripe tomatoes that you can find. Consider those that are especially suitable for sauce. Watery tomatoes are not desirable for making homemade passata. If your tomatoes are watery, you will need to cook the passata before jarring to thicken.)
No mill? No problem. If you don’t have a mill, you can use a food processer, but then will need to strain your tomatoes through a sieve or cheesecloth to remove seeds and skins.
Watery tomatoes? If your passata is not dense or thick enough, you can put the pot of passata on the stove (after step 5) and allow it to reduce. The risk, of course, is that the passata will lose its fresh-tomato flavor. One way to avoid a passata that is too watery is to cut the tomatoes in half, and then squeeze them in your hand into a bowl before cooking. This will remove much of the water and seeds. This method is often used by professional cooks to quickly obtain the pulp of the tomato to work with it in a quicker and cleaner way.

Preserve Tomatoes Chunky-Style

Do you prefer a chunkier tomato sauce? Pomodoro a pezzi is an alternative method for preserving tomatoes. This method is not technically a passata, because it is made without the use of a vegetable mill.

First make a quick, shallow cross with a knife on each tomato, and then, blanche the tomatoes in boiling water for just a minute. Transfer them to a cold-water bath so that you may easily peel them. The skins should peel off very easily. Halve the peeled tomatoes. Remove excess water and seeds by hand. Next, cut the tomatoes into chunks.

Follow steps 6 through 8 to complete your chunky-style tomato sauce.

This method results in a fresher tomato flavor and heartier pieces of tomato, since they are cooked for a shorter period of time. If you prefer the entire whole peeled tomato, do not halve the tomatoes before you place them in the jar, but note that your jar may contain more water later after settling.