The Jewish holiday of Passover begins tonight at sundown, meaning no leavened bread- or any grains used to make leavened bread- for 8 days. We don’t buy much processed food, but it’s still difficult to avoid corn products- high fructose corn syrup in particular- that turns up in the most unlikely places. So when I saw we had some extra grapes in the fridge this morning, I decided to make some fresh, corn-syrup-free jam for Passover.
The process is surprisingly easy, and you don’t need to buy pectin or any other gelling substance. Sugar can be used to preserve fruit, so you just need equal amounts (in weight, not volume) of grapes and sugar (we’ve also done cherries this way). Or you can make grape jelly by using grape juice instead of whole grapes. Lots of people use concord grapes that are easy to take the skin off of. I don’t even know what kind of grapes we had, but they weren’t easy to peel so I just left the skins on.
I threw the grapes in a big pot over high heat and mashed them up a little to get some juices flowing. No need to add water, since more liquid gets released as the grapes cook. Once everything was nice and soft, I pureed the mixture to get a more even consistency, then added the sugar and returned to the heat.
Since this process doesn’t use pectin, the thickening is achieved by continuing to boil the mixture to cook off the liquid. It took about 20 minutes to get to a good consistency. To test, take a cold plate (I put it in the freezer) and drop a spoonful of jam on it, then return to the freezer for a minute. This will give you a good idea of the consistency your jam will be once cooled, and you know it’s done when it holds its form and wrinkles when you push on it.
If you’re making a lot of jam, you’ll want to use a water bath to can it all. We made a small batch this time: two-and-a-half pounds of grapes and two-and-a-half pounds of sugar made exactly one quart of jam. We poured it into a mason jar and will keep it in the fridge.
Now all we need is a great peanut harvest this season- PB&Js from scratch!