Santa Rosa Plum and Strawberry Jam with Rosemary

Source: Rachel Saunders, author of The Blue Chair Jam Cookbook (Andrew McMeel, 2010)


It was prepared for CUESA’s Market to Table program on July 16, 2011.

Approximate yield: six 8-ounce jars
Shelf life: 1 year


1¼ pounds pitted and halved Santa Rosa plums
1¼ pounds pitted Santa Rosa plums, thickly sliced
¾ pound plus ¾ pound hulled strawberries, thickly sliced
14 ounces plus 14 ounces white cane sugar
2 to 5 ounces strained freshly squeezed lemon juice
2 to 3 (10-inch) sprigs rosemary


Day 1
Have ready 2 medium glass or hard plastic storage containers with tight-fitting lids.  In the first container, combine the halved plums with ¾ pound of the strawberries and 14 ounces of the sugar.  Cover and let macerate in the refrigerator for 24 to 48 hours.  In the second container, combine the sliced plums with the remaining ¾ pound berries and 14 ounces of sugar.  Cover and let macerate in the refrigerator for 24 to 48 hours.

Day 2 or 3
Place a saucer with five metal teaspoons in a flat place in your freezer for testing the jam later. 

Remove the fruit from the refrigerator. Put the halved plums and their sugar through the fine holes of a food mill and add them to the second container with the sliced plums. Scrape any solids that will not go through the food mill back into the jam mixture, breaking up the chunks as you go. Transfer the mixture to an 11- or 12-quart copper preserving pan or a wide nonreactive kettle

Stir in 2 ounces of the lemon juice. Taste and slowly add more lemon juice if necessary. You should be able to taste the lemon juice, but it should not be overpowering.  Keep adding lemon juice only just until you are able to detect its presence in the mixture.

Bring the jam mixture to a boil over high heat.  Boil, stirring frequently, for 4 minutes.  Remove from the heat and, using a large stainless steel spoon, skim the foam from the top of the mixture and discard.  Return the jam to high heat and continue to cook, monitoring the heat closely, until the jam thickens, about 30 minutes.  Scrape the bottom of the pan often with your spatula, and decrease the heat gradually as more and more moisture cooks out of the jam. For the final 10 minutes of cooking, stir it very frequently to provide scorching.

To test the jam for doneness, carefully transfer a small representative half-spoonful of jam to one of your frozen spoons. Replace the spoon in the freezer for 3 to 4 minutes, then remove and carefully feel the underside of the spoon.  It should be neither warm nor cold; if still warm, return it to the freezer for a moment. Tilt the spoon vertically to see how quickly the jam runs; if it runs very slowly, and it has thickened to a gloopy consistency, it is done.  If it runs very quickly or appears watery, cook it for another few minutes, stirring, and test again as needed.

Turn off the heat but do not stir. Using a stainless steel spoon, skim all the remaining foam from the surface of the jam. Place the rosemary into the mixture and let steep for a few minutes off the heat.  Stir and carefully taste the jam and either remove the sprigs or leave them in for another minute or two, keeping in mind that their flavor will be slightly milder once the jam has cooled. Using tongs, discard the rosemary. Pour the jam into sterilized jars and process according to the manufacturer’s instructions.


Photo by Barry Jan.

Farmers Market Ingredients