Our favorite book back then was Each Peach Pear Plum, by Janet and Allan Ahlberg. It inspired the combination of fruit in this jam—peaches, pears, and plums. We made it both for immediate consumption and gift-giving throughout the fall and winter. We named it Tom Thumb’s jam based on a character in the book. My holiday gifts were covered, and we feasted on jam and toast in the meantime.

How to Select the Best Fruit for Jam

Peaches, pears, and plums hang around through mid-September and they make a stellar combination for preserving into this unique jam. When you are making jam, select the best fruit available. Firm and perfectly ripe or slightly underripe fruit has the highest level of acidity and pectin, which will give you the best results. Relegate overripe or blemished fruit to the blender for smoothies with a good squeeze of lemon if you want to avoid waste. Too underripe, your jam will lack flavor. Sample the fruit and you will have an idea of what your jam will ultimately taste like.  You can also use frozen fruit—either store-bought or fruit you freeze yourself—if you have the fruit but don’t have the time to do anything with it, freezing is a great option. You can get to your jam-making when the spirit moves you later. 

Specific Fruit Recommendations 

For this jam, you can really use any variety of peaches, pears, and plums that are available to you. That said, here are some of my recommendations:  Peaches: I like to use yellow peaches because they are tangy and sweet. White peaches are sweeter, softer, and have less acidity. Freestone peaches, available mid to late season are the easiest to pit. Pears: Red and green Anjou pears, golden brown Boscs, and green Comice pears are readily available and hold their shape well when cooked—it’s better than it turning to mush, which makes the jam muddy. Choose firm but ripe pears and peel, core, and cut them into 1-inch pieces. Plum: There are too many varieties of plums to count, ranging from green and red to almost black. Dark-skinned plums will give your jam the prettiest color, but all plums are good candidates. No peeling necessary!

Tips for Cooking the Jam

Unfortunately, there is no magic number on the thermometer to indicate that the gelling point for your jam has been reached. This is just a matter of practice. The fruit syrup starts out runny and gradually thickens until it sheets from a spoon. A perennial second-guesser, I like to test it in a cold saucer just to be sure. The time it takes to cook the jam depends on how the acidity and pectin in the fruit interacts with heat and sugar. Start by using a large pot and fill it only halfway. As the jam cooks it tends to bubble up—so give it plenty of room. You may notice foam rising to the surface as the fruit cooks. Don’t skim it! Just ignore it—if you start skimming early there will be no jam left. Instead, wait until it reaches the gelling point, and if there’s still foam around the edges you can skim it.

Can Your Jam for Longer Storage

In the unlikely case you eat all the jam within a few weeks, you can store it in the fridge. But that takes up a lot of real estate. Instead, use the water bath canning method below and your jam will keep for up to 1 year outside the fridge.

More Canning Recipes to Try

Apricot Riesling Jam Rose Hip Jelly Meyer Lemon Marmalade Seville Orange Marmalade Chia Seed Jam with Berries

Test the jam using a saucer: For second-guessers, use the saucer method to confirm the gelling point. Spoon a small puddle of the syrup onto a cold saucer from the freezer. Put it back into the freezer for about a minute. Remove it and draw your finger across the middle to form a channel. If the surface of the jam wrinkles and the channel does not close immediately, your jam is ready. Process the jars in a boiling water bath for 10 minutes using the guidelines below.  Did you love this recipe? Give us some stars below!