Making Grape Jam

Last year I made jam for the first time. The instructions in the Ball Blue Book of Canning said to use Concord, Muscadine, or Scuppernong grapes and to slip the peels from them, chop up the peels, then put the peels into the jam later. I don't know what kind of grapes grow here - they are on a trellis and were here when we bought the place. So I called my Grandmama to see how you peel grapes.

Apparently those three types just jump right out of their peels. I thought all was lost, as I have "regular" grapes, but Grandmama told me how to make jam with the grapes I have.

Pick the grapes - pick the super ripe ones and the not so ripe ones. The ones that aren't quite ripe have more pectin in them, and pectin is what makes the jam jell.

I used the ingredients and proportions in the Ball Blue Book. It calls for two quarts of grapes. I've learned, after several batches, that I need to be generous with what I consider "a quart". Above is a four cup measuring cup and as you can see I fill it quite a bit more than four cups.

After the grapes are washed I put them in a saucepan. Some of them have fallen out of their peels during the washing process. I don't add water (there is a bit on them from having been washed), I just start at low heat. They will juice a lot as they cook.

At this point I also put three pint jars into my canner, submerse them in water, and put the heat on high. Jam is canned with a boiling water bath, and it takes a long time to heat up all that water. So start early.

I simmer the grapes until they're mostly slipped out of their skins.

Once they're cooked and pretty much soft, put them through a ricer or a Foley mill. This will separate the skins and seeds from the juice and pulp.

Use a big pot - 8 or 12 quarts. When you cook the jam it boils up amazingly, impressively, and just a little big frighteningly.

Add six cups of sugar. That's a lot of sugar! I bought my sugar in 25 pound bags at Sam's or Costco, and it was under $12. The bag says 25 lbs. is just over 56 cups.

Pop a small bowl or saucer into the freezer. You'll need it later.


Cook the grape/sugar mixture until it reaches the jelling point. Stir frequently to keep it from getting thick and sludgy on the bottom. Don't let it boil too high because it will want to splash onto your hands when you stir it. Boiling sugar/fruit juice is VERY hot and doesn't like to come off.

The jelling point will vary depending on ambient temperature, humidity, pot used... it's a bit of a black art and, frankly, I'm never sure if I've made jam that will be too thick or too runny. I tend to make it thicker than I think I'm making it.

You can get it approximately to the jelling point by bringing some water to a boil and checking your boiling point on that day with a candy thermometer. The jelling point will be about eight degrees higher than the boiling point of water. Don't assume water really boils at 212F where you live.

I find that it takes about 20 minutes for my grapes to reach the jelling point, but I usually start testing after 15 minutes, just in case.


To test, remove the jam from the heat so it doesn't cook while you're testing. Put a bit on your cold saucer or bowl and pop it back into the freezer for a minute or two.

You should test it when the jam is "room temperature." It's hard for me to tell what "room temperature" is after hovering around stirring boiling jam. I know it's cooler than my wrist (and cooler than my tongue).

The jam above is still too runny. I was rocking out to a Journey CD... sorry for the racket.


This jam is about right.
I think.
It may be too thick.
What do I know?

This shows how the jam looks in the bowl after testing and tasting ;)

Process in a boiling water bath for 15 minutes (pints). Adjust for altitude.