Even after the appearance of commercial tomato ketchup, homemade mushroom variations lingered as an American favorite into the early decades of the twentieth century. Two of the most popular cookbooks of the period—Marian Harland's Complete Cook Book and Mrs. Rorer's New Cook Book—presented spiced-up recipes, flavored in one case or the other with ground ginger, mustard seeds, cloves, port, onions, and paprika. We take inspiration from these seminal versions, hoping to show why the old idea shouldn't be allowed to die.
MAKES ABOUT 2 CUPS
| 1 | pound portobello mushrooms, caps halved and caps and tender stems sliced thin |
| 1 | tablespoon kosher salt or other coarse salt |
| 2 | large shallots, cut into chunks |
| 2 | garlic cloves |
| 2 | cups water |
| 1 | cup red wine vinegar |
| 1 | tablespoon paprika |
| 1 | teaspoon dry mustard |
| ½ | teaspoon ground ginger |
| ½ | teaspoon ground allspice |
| ¼ | teaspoon ground cloves |
| 3 | tablespoons port or sweet red wine |
Plan to make the mushroom ketchup over 2 days. Place the mushrooms in a large ceramic, glass, or stainless steel bowl. Mix the salt with the mushrooms, cover with a clean dish towel, and set them aside in a cool spot for 12 hours or up to 24 hours. We normally do this step one evening and let the bowl sit out overnight.
In a blender, preferably, or a food processor, combine the mushrooms and accumulated liquid with the shallots, garlic, and enough of the water to purée it easily. You will probably need to do this in two batches. Spoon the purée into a nonreactive saucepan and pour in any remaining water, the vinegar, and the spices. Bring to a boil over high heat, reduce the heat to low, and cook the mixture for 45 to 50 minutes,stirring occasionally at first and more frequently near the end. The ketchup is the proper consistency when it's a little thinner than store-bought tomato ketchup. Add the port and cook for 3 to 5 additional minutes. Use the ketchup warm or chilled. It keeps, covered and refrigerated, for several weeks.