Autumn’s rushing in and the tomatoes are petering out, right on schedule. The last of the green ones will eventually ripen indoors, but I like using them to make chutneys, mincemeat, and marmalade. After experimenting over the years, my favorite recipe for tomato marmalade is a tangy one that includes lemons and fresh ginger. My husband thinks he doesn’t like tomato marmalade at all, so I labeled it “lemon-ginger preserve” and he’s happily eating it. Don’t tell.
One trick to getting marmalade or jam to the right consistency is to use a wide, non-reactive pot; the more surface area bubbling away, the faster the evaporation, which helps the mixture set up and be nicely spreadable. All kinds of variables — the juiciness of the tomatoes, the humidity, how fast the mix simmers — affect cooking times. You have to test, but otherwise it’s a really simple recipe.
4 lbs green tomatoes
Juice and zest of 5 lemons
¼ cup fresh ginger, peeled and minced
6 cups sugar
Wash and core the tomatoes (you can leave the skin on), then cut them into small chunks. Put the tomatoes, lemon juice, zest, and ginger into a heavy, wide pot and simmer over medium heat for about an hour, stirring occasionally. Add a little water if it looks as though the mixture might stick.
Add the sugar, stirring until it’s dissolved, then bring to a boil and continue simmering rapidly until the mix sets up and becomes jammy — half an hour or so. Check often and stir to be sure it doesn’t scorch. Before you take the marmalade off the heat, test the consistency by putting a spoonful onto a chilled plate. Wait a minute or two. If it’s still runny, boil the mix for a few minutes more and test again. Or use a jelly thermometer: setting point is 220 degrees.
Pour the marmalade into hot, sterilized jars and seal. You can process the jars in a canning bath for 10 minutes, but I just cap mine and store them in the cellar. Sugar is a preservative, tomatoes are acidic, and boiling the mix will have killed any existing bacteria, so if you sterilize the jars and caps, you shouldn’t have a problem with mold. Once a jar is opened, store it in the fridge.