Appetites: Preserving homegrown tomatoes

Chef Amy Thielen, author of "The New Midwestern Table," joined MPR's Tom Crann to talk about tomatoes.

Every year, I preserve tomatoes from my garden — for the thrift of it, and because my beautiful heirloom tomatoes taste light years better than anything I can buy at the store.

Here's the thing: if you want to cook with sweet, tender tomatoes that actually taste like tomatoes, you've got to either pony up $5 for a can (or more) for a quart of imported San Marzano roma-type tomatoes from Italy or you've got to preserve your own.

How to do it

The advantage of preserving homegrown or farmer's market tomatoes is that you can pick varieties with thicker flesh and thinner skins. And ideally, for sauce, you want a roma tomato, one of those ovoid kinds with denser flesh, fewer seeds and less juice, and you want an heirloom variety with thin skin.

You might say I'm just being picky, but you can see the difference in commercially canned tomatoes: Buy a can of whole tomatoes in puree, pour them out into a bowl, and crush them with your hands.

The cheap, commercial ones are tough, with hard, uncrushable stem ends; the heirloom tomato squishes up between your fingers when you crush it, almost turning into sauce without cooking. That one's going to taste brighter, sweeter, more acidic, and a whole lot better — and that's just because they started with a better tomato. It has virtually nothing to do with the canning process.

So, bottom line, start with good tomatoes, and wait until they're super ripe before canning them.

In my experience, you can't judge the ripeness of tomatoes (and especially the roma tomatoes) by their color alone. They can be red but still firm. Let the red ones sit at room temperature for five to 10 days, until they feel soft when pressed. That's when they're ready.

Other Tomatoes

I preserve my beefsteak tomatoes too, the big round tomatoes that are meant for fresh eating-otherwise known as "slicers." These have more juice to deal with, but that's OK. The very easiest way to preserve these is to just pop them into a zip-top plastic freezer bag-and freeze them whole.

To use them, defrost them in a colander over a bowl. The skins will slip right off and as they thaw, they'll lose some of their tomato water, making their transition to a thick sauce that much quicker — and you can use that tomato water as a vegetable stock.

Ranchero Sauce

But in addition to putting up quarts of tomato sauce, and whole tomatoes in puree, I also make a more unusual sauce that's so good it deserves wider recognition: ranchero sauce, the spicy chile-and-tomato sauce that surrounds the huevos in huevos rancheros.

This is not a sauce that you can easily find in stores. Maybe if you go to a Mexican specialty store you'll find ranchero sauce. But the most surefire way to keep yourself supplied with ranchero is to make your own. And your own will taste so much better.

Also, because it's pureed, it's the easiest of my tomato canning projects, and it doesn't take much of my time to make 10 or 12 pints.

For this recipe, I began with one from Diana Kennedy, an expert on authentic Mexican cuisine, and then tweaked it to fit my taste-memories of my favorite huevos rancheros.

Then I tested the sauce with my pH meter to make sure it had enough acidity, and I've been running with it ever since. In the winter, on one of those blue-light mornings, opening a jar of ranchero sauce for our weekend eggs transports us all straight back to summer.

Ranchero sauce recipe

Yields 4 1/2 pints

13 pounds ripe tomatoes, peeled and seeded

12 cloves garlic

7 dried chiles (mixed bag of piquillo, guajillo, and ancho, heavy on the guajillo)

1 small onion, cut in half

1 teaspoon ground chipotle (or add 1 dried or canned chipotle to the above)

1 red jalapeno (or cayenne to taste)

¼ teaspoon cumin seeds

1 clove

3 1/2 teaspoons salt

1 tablespoon sugar

1 cinnamon stick

2 tablespoons white wine vinegar

Remove the tops and most of the seeds from the dried chiles. Place them in a small bowl and cover with boiling water. Let steep until cool.

Toast garlic cloves, in their skins, in a dry cast iron skillet over medium heat until brown in spots. Cool and peel.

Toast the cumin and clove in the skillet until fragrant. Mash in a mortar until fine (or use a spice grinder).

Heat a film of canola in the same skillet and quickly brown the onion on both sides.

Place the chilies, spice mix, garlic and onions and a few tomatoes in the blender. Blend on high until smooth, and push through a sieve into a large pot, pushing on the sieve with the back of a ladle to extract liquid.

Place the pulp back in the blender for another go-around. Top with tomatoes and blend at top speed until smooth. Strain again, this time discarding the pulp.

Blend the rest of the tomatoes until smooth, pouring them into the pot without straining. Add the salt, sugar, cinnamon stick, and vinegar, and cook at a simmer for about 1 hour, or until the sauce thickens and no longer separates.

Ladle the sauce into sterilized glass jars, top with sterilized lids. Process the jars in a boiling water bath, counting from the time the water returns to a boil: 15 minutes at 0 to 1,000 feet altitude, 20 minutes at 1,001 to 6,000 feet, and 25 minutes at an altitude of 6,000 feet or greater.

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