A jam is a jam is a jam, right? Perhaps, but there are little tips and tricks that can take an ordinary jam to new heights.
After harvesting mountains of peaches and nectarines from Masumoto Family Farm, I worked with my friend and colleague Shakira Simley of Bi-Rite Market to make some jam -- a lot of jam. Between their harvest and mine, we processed about 120 pounds of fruit.
Shakirah is a Master Food Preserver, and studied preserving at the University of Gastronomic Sciences in Italy, so I always pick up a trick or two from her. For stone fruit specifically (that is, apricots, peaches and nectarines), she likes to cook the fruit a bit first before adding sugar. As the fruit heats, it opens up and becomes more receptive to the sugar. Then, when the sugar dissolves into the liquid to become a syrup, it penetrates the fruit more easily, and you reach a better set, even with relatively low sugar levels.
Normally, I macerate my fruit in advance of making a jam -- in other words, allow the fruit and sugar to stand together to draw out liquid -- but this method works out to be simpler and faster. Before long, our jam was perfectly viscous and dense. A splash of lemon juice adds some brightness and protects color. This is key especially for lower-sugar preserves, which can lose their luster more rapidly. For this jam, I'm using only 30% sugar to fruit by weight, about as low as you can go and get a proper set.
This method works as well on nectarines as on peaches and apricots, but the nectarine flavor really shines here. It's sure to be a welcome dose of summer sun when the days grow colder and dark.
- 5 pounds nectarines (diced)
- 1 1/2 pounds sugar
- 2 tablespoons lemon juice
Wash and dice the nectarines, discarding the pits. You do not need to peel the nectarines. Weigh out 5 pounds of the fruit. Add it to a heavy, non-reactive pot. Add a small amount of water to the bottom, and place the pot over medium-high heat.
Bring to a boil, stirring to prevent scorching. The fruit will give off quite a bit of liquid. Boil for a few minutes, until the fruit begins to look translucent.
Add the sugar, and stir to blend completely. Return to a boil, and cook, stirring occasionally, until the jam reaches the set point. Add the lemon juice, and stir to combine.
Pack the jam into clean half-pint jars. Seal and process for 10 minutes in a water bath canner.