Green Tomato Jam

A sweet way to use end-of-season tomatoes

As we’ve moved into autumn here in St. Louis, our garden has continued to put out late-season goodies. Including quite a few tomatoes that didn’t have time to ripen before the summer sun faded.

We happily harvested our green tomatoes—but then had to figure out what to do with them. Fried green tomatoes? Nah, been there, done that. Curried Green Tomatoes? Terrific, but we did that last year. We wanted something really different.

So we decided to make Green Tomato Jam. It’s wonderful with biscuits or on toast. And you can even use it as a “sauce” or garnish on meat (it’s spectacular with pork roast).

But we have to make a confession here: Our favorite way to consume Green Tomato Jam is straight from the jar. By the spoonful. Take that as a warning.

Recipe: Green Tomato Jam

There are lots of recipes for green tomato jam, and all are pretty similar. Basically, every recipe contains green tomatoes (natch), plus sugar, some citrus for acid, and a bit of flavoring.  

The recipe we like best is one we found on Lynne Rossetto Kasper’s Splendid Table website. BTW, the link takes you not only to her recipe for green tomato jam, but also to instructions for a tart you can make with the jam.

This recipe takes about 10 minutes of prep time, plus 40 or more minutes of cooking time. The recipe yields 4 to 5 cups.

We don’t preserve the jam, just refrigerate it. It should keep for a month or longer in the fridge. You can also freeze the jam.

Ingredients

• 3 pounds green tomatoes
• 2 2/3 cups sugar
• 3 lemons
• ¼ teaspoon Kosher salt (half that amount if using regular table salt; see Notes)
• ¼ teaspoon freshly ground black pepper
• 1 stick of cinnamon (optional but tasty; see Notes for additional spice ideas)

Procedure

1. Wash the green tomatoes and dry them. Core the tomatoes (remove the stem ends) and cut them into ½-inch pieces.
2. Place the cut-up tomatoes (and any juice that might have escaped) into a large bowl made of a nonreactive substance (stainless or glass). Add the sugar and toss together. Cover with plastic wrap and leave at room temperature overnight (or up to 24 hours).
3. Next day: Pour the tomato mixture into a large, wide Dutch oven or cooking pot (one that holds 6 quarts or more; you want a pot that is wider rather than taller to help speed evaporation of excess water from the jam).
4. Zest the lemons (you can use a zester, although we find it easier to use a microplane grater). If necessary, mince the zest until it’s finely shredded. Cut away the white pith of the lemons and discard. Seed the lemons and cut them into small pieces.
5. Add the lemon (zest and pieces) to the pot with the tomatoes. Add the salt, pepper, and cinnamon stick. Over high stovetop heat, bring the tomato mixture to a boil. Then reduce the heat so the jam is cooking at a moderate simmer, and set a timer for 40 minutes. Stir the pot from time to time with a wooden spoon while the mixture is cooking. You want to cook away the water in the tomatoes—you’re aiming for a mixture that is translucent, with thick juices.
6. At the 40-minute mark, check the temperature of the tomato mixture with an instant-read thermometer or a candy thermometer. The jam should reach a temperature of 215 or even 220 degrees F (see Notes for more on temperature). If you don’t have a thermometer, test for doneness by spooning a tiny bit of jam onto a chilled plate. If it runs, cook the jam a bit longer. If it doesn’t run, it’s done.
7. Once the jam is cooked, take it off the heat and remove the cinnamon stick. We usually pour the jam into a clean bowl at this point so it can cool more quickly.
8. When the jam is cool, ladle it into clean glass jars (in a pinch, you can use plastic containers). Cover the containers and refrigerate.

Notes

• Kasper suggests that green tomato jam should be done at a temperature of 210 degrees F (because if you heat it higher than that, the flavor won’t be quite as bright). In our experience, however, the jam sets better at a slightly higher temperature, so we recommend 215 or even 220 degrees F. Yes, you may lose a few flavor nuances, but you’ll be sure that the jam will set up properly.
• Cinnamon adds a pleasant (but subtle) note to the jam. If you want a more assertive taste, you may want to double the amount we specify. 
• Some recipes for green tomato jam add a bit of ginger (you can try a piece an inch or so long, peeled and finely minced).
• Or add a few whole cloves (fish them out of the jam in Step 7 when you remove the cinnamon stick).
• Or try a whole vanilla bean (again, remove it in Step 7).
• If you want a spicier jam, you could add some cayenne pepper to the mix—say ½ teaspoon or so.
• Kosher salt is more coarse than regular table salt, so it’s less salty by volume. If you’re substituting table salt for Kosher, always use less—about half as much.
• Green tomatoes look a bit like tomatillos. But their flavors are quite different, so you can’t really substitute one for the other.
• Where to get green tomatoes? The best place is from your own home garden, if you have one. Or beg some from your neighbor’s garden. Farmers’ markets are another good source—they’ll often have them right at the beginning of the season, or at the end. We’ve never seen them at the supermarket, however.

Jam Today, Jam Tomorrow

“This Green Tomato Jam is wonderful,” said Mrs. Kitchen Riffs, spreading some on a homemade biscuit.

“Terrific flavor,” I said, munching. “And a great way to use the last of our tomatoes.”

“In fact, about the only tomatoes we managed to harvest,” said Mrs K R. “Since the squirrels got the rest of them this year.”

“Don’t remind me,” I groaned. “They chewed right through the protective netting I put up, and swiped most of our ripe ones!”

“They did put you in a bit of a jam, didn’t they?” said Mrs K R, taking a bite.

“They did,” I replied. “But I’ve got some ideas to jam their channels next year.”

Mrs K R smiled. “Don’t jam your thumbs trying.”

Sigh. Knowing me (and the squirrels), I’ll probably jam something up.

You may also enjoy reading about:
Curried Green Tomatoes
Baking Powder Biscuits
Beer Bread
Homemade Butter
Easy Pickled Watermelon Rind
Peach Salsa
Or check out the index for more