Katy's Organic Plum Jam | CUESA

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Katy's Organic Plum Jam


Katy Gronowski, Preserves Contest Winner

This jam won first prize in CUESA’s Summer Jam Preserves Contest at Jack London Square Farmers Market Harvest Festival on July 15, 2018.


5 cups pitted plums (Katy’s note: I used organic purple plums, which I picked before they were ripe)
5 cups organic sugar  
2 tablespoons lemon juice 
6 tablespoons pectin
1 tablespoon butter (optional)


1. Sterilize six 8-ounce jars and lids. You can sterilize by boiling the jars on a rack or by putting them in a preheated 250 degree oven for 20 minutes.

2. Pit the plums and cut them in half. Discard pits.

3. Put the plums in a pan with ½ cup of water and cook for 5 minutes over high heat, stirring frequently.

4. Put the plum mixture in a blender and pulse for 10 seconds. This breaks up the skins of the plums and gives the jam a nice, thick consistency.

5. Return the plum mixture to the pan. Add pectin and stir thoroughly. Add lemon juice and sugar.

7. Bring the jam to a rolling boil and allow it to boil for one minute. Add 1 tablespoon butter (if desired) to reduce foaming.

8. Pour jam into warm, sterilized jars leaving ¼ inch space at the top of the jar.

9. Allow jam to cool. Seal jars with lids and then sterilize filled jars. Jam may be stored for a year. Once opened, consume within a month.


CUESA (Center for Urban Education about Sustainable Agriculture) is dedicated to growing thriving communities through the power and joy of local food. Learn More »