Slightly underripe tomatoes. Ginger root. Alum. Sugar.
Select large round tomatoes. Wash them in cold water and then cut in halves at right angles to the stems. Remove the seeds and throw tomato halves into alum water, allowing one ounce of alum to one-half gallon of water.
Weigh the tomatoes, allow as many pints of water as there are pounds, and one ounce of bruised ginger root to each pint of water; boil the ginger and water together until quite strong, then add one pound of granulated sugar for each pound of tomatoes and boil to a syrup.
Now add the tomatoes and cook gently for two hours, or until the fruit is rather dark. Remove the tomatoes and turn them into jars, boiling down the syrup until it is quite thick before pouring it over them; place a small piece of the ginger on the top of each jar and seal at once.