Makes4 or 5 (1/2-pint) jars
- Active Time:2 hr
- Start to Finish:3 hr (plus 1 day for flavors to develop)
I've often made this luscious spread with little yellow plums gathered from my friend Ilene's fruit trees. Red or purple plums work equally well. Because fruit butters are slowly cooked down to a thick paste, they require a good deal of stirring to prevent scorching.
vanilla bean, halved lengthwise
ripe plums, cut into 1/2-inch wedges
fresh lemon juice
Freeze several small plates to use for testing butter.
Scrape seeds from vanilla bean into a 5- to 6-quart heavy pot. Add pod and stir in remaining ingredients. Slowly bring to a rolling boil over moderate heat (this will take about 15 minutes), stirring frequently. Boil, uncovered, stirring frequently, until plums are tender, about 5 minutes.
Discard pod. Purée plums with liquid in batches in food mill set over a bowl. Transfer purée to pot and simmer over low heat, stirring and scraping bottom of pan frequently, until very thick, about 1 1/2 to 2 hours. (To test for doneness, drop a spoonful of plum butter on a chilled plate, then tilt; the mixture should not be runny. It should be about as thick as jam.)
Drain jars upside down on a clean kitchen towel 1 minute, then invert. Ladle plum butter into jars, leaving 1/4 inch of space at top, then run a thin knife between plum butter and jar to eliminate air bubbles.
Seal, process, and store filled jars
, boiling plum butter in jars 10 minutes.
Let plum butter stand in jars at least 1 day for flavors to develop.