The Summer of Jam!
Ham and I have been on a jam-making kick. It happens every year near the end of summer. We'll process flats of ripe fruit from the market and fill up every jar we've got. Initially, I get annoyed about how much space all the preserves take up in the pantry. Still, swirling a spoonful of homemade sour cherry jam into yogurt in the middle of December is always thrilling.
We typically make jam like our mothers, eyeballing the entire process, adding sugar and lemon juice to taste, and cooking until the mixture sets up on a chilled plate. Even when I worked as a pastry chef and cooked down entire cases of fruit in wide rondeaus, I did it all recipeless, and the result was fine. This year we kicked off our jam journey with 6 pints of red currants from Philips Farm at Union Square farmers market. The fruit was so perfectly plump and sour that we wanted them to be more than just fine, so we used a method adapted from Jessica Koslow's The Sqirl Jam (Jelly, Fruit Butter, and Others) Book.
A few years ago, Koslow was at the center of jam-gate, so I was hesitant to try her recipe, but I am glad we gave it a go. She has a unique step called blending and plumping. First, the fruit is combined with sugar and lemon juice, covered, and allowed to rest for at least 3 hours, and preferably overnight in the refrigerator. The next day it is brought to a boil, covered, and rests again for at least 3 hours, and preferably overnight in the refrigerator. Finally, the mixture is simmered into jam.
Koslow say this is a French process that allows the fruit to slowly absorb the sugar, allowing big pieces to be suspended with in the preserves. Damn, the difference was incredible. We are like Bonne Maman over here, making gently set clear jells with fruit suspended throughout. I tried to find other recipes with this blending and plumping step but haven't seen anything similar in my cookbooks or online. If any of you know more about the origins of this method, I'd love to learn more!
Here's a guide to Koslow's jam method:
Weigh the pitted, stemmed, or hulled fruit
Combine with 55% to 60% granulated sugar and 2% to 4% freshly squeezed lemon juice. (Koslow has specific amounts for each fruit, but they all fall within that range. We decided where in that range we would land based on how sweet or tart each fruit tasted.)
Blending and plumping: Crush the fruit with your hands or a potato masher (or keep them whole), cover, and rest at room temperature for at least 3 hours, or (preferably) in the fridge overnight.
Scrape the mixture into a pot and bring it to a boil over high heat, stirring constantly. Return to bowl, cover, and rest at room temperature for at least 3 hours, or (preferable) in the fridge overnight.
Scrape the mixture into a pot and bring it to a boil over high heat, using a ladle to skim off any scum that floats to the surface.
Clip on a candy thermometer and simmer, occasionally stirring, until the mixture registers between 214F to 221F, depending on how set you want your preserves. (Test how set it is by spooning a dollop onto a chilled plate.)
These are the ratios we used for our jams:
Red currant jam: 60% sugar and 2% lemon juice (lightly crushed by hand), cooked to 217F
Blackberry jam: 60% sugar and 4% lemon juice (lightly crushed by hand), cooked to 220F
Mara de bois strawberry jam: 55% sugar, 3% lemon juice, and the seeds and pod of 1 vanilla bean (hulled and kept whole), cooked to 217F
We will likely make another couple batches before the season is over. Got any suggestions? How do you all make your preserves? Let me know if you've tried this method and if it works for you!