During the summer Mustang grapes grow all over our area. Mustang grapes are similar to muscadine grapes. We use these tart grapes to make grape jelly and juice, of course, but we also use them to make grape jam.

Grape jam is usually made with whole grapes that have been seeded but I prefer to use the leftover grape mash, sometimes called grape must, for this grape jam recipe.

I always juice the grapes to make wild grape jelly and juice, then I use the leftover mash to make grape pie filling and grape jam.

I use the grape mash because I try to use as much as possible when we preserve food. It’s pretty amazing to see 8 gallons of grapes turned into delicious shelf stable food with only a gallon of waste left.

This grape jam recipe doesn’t have to be used with grape leftover grape mash, you can use fresh seedless grapes which makes this a great recipe to make when you’ve bought grapes and no one is eating them.

Sometimes store bought grapes are sour or just aren’t as flavorful as we’d like so they don’t get eaten as quickly as I think they will. Or maybe we just happen to have a lot of other fruit that we don’t buy very often, like mangoes, so the grapes go untouched.

Either way, making grape jam out of these seedless table grapes is a great way to make sure they don’t go to waste. I’ll show you how to prepare whole grapes for grape jam below.

Making Grape Must

Grape must is crushed grape juice with the seeds, skin, and even stems in it, and is the first step in wine making.

Grape mash is the left over stuff from making grape juice. The easiest way to juice grapes is with a steam juicer.

For years I juiced grapes by boiling them down and then squeezing the mash through a jelly strainer. It’s fun but super time consuming and messy. My life was changed when I got the steam juicer.

Mustang grapes have seeds so after they’ve been juiced I put the mash from the steamer in a food mill and remove all the seeds. It’s super easy.

If your grapes don’t have seeds you don’t need a food mill. You can use a regular blender, food processor, or immersion blender to break the grapes up and make grape mash.

But usually even seedless grapes have small seeds in them.

Grape jam can be made with or without the skins. I think the skins add tartness and more flavor to grape jam and we like that. If you don’t want the skins in the jam, you can peel the grapes or use a food mill.

Preparing Whole Grapes

To make grape jam with the whole grape you’ll want to use the skin to give the jam texture and color but not the seeds.

If you use a food mill, it will remove the seeds but it will also remove the skin. If you want to keep the skin you’ll need to remove the seeds by hand.

The seeds can be removed a couple of different ways. The first way is to cut each grape in half and take out the seeds.

The second way would be to peel the grapes and put the peels in one bowl and the pulp with the seed in another bowl. Then press the pulp through a mesh strainer or food mill.

Some grapes will be easier to peel than other – green Thompson grapes are more time consuming but mustang grapes can easily be squished out of their skin.

Either way, this can be time consuming but that doesn’t mean it’s not worth it. These are the types of jobs that cause us to slow down. Jobs that keep our hands busy but our minds free. Jobs that when done with others spur good conversation. Jobs that when done alone allow you to be still, listen to music or an audiobook and enjoy the moment.

Making Grape Jam

Now you’re ready to make the grape jam. The first thing you want to do is put three or four metal spoons in the freezer. You’ll want these later, I promise.

Because every time we process grapes we end up with a different amount of grape mash I don’t use a precise recipe for grape jam – instead I use a ratio.

Unlike when you make jelly and need precise amounts of sugar, acid, and pectin to make it gel, when you make jam, you can leave out the pectin and just cook the jam until it reduces down and gels.

Mustang grapes are tart, if there were a tartness scale for grapes, like the spicy scale for peppers, mustang grapes would be at the top of the scale.

If the grapes you’re using aren’t as tart you might not need as much sugar. If you use mustang grapes, you might want to use even more sure than I do since we like our grape jam tart.

I use 2 cups of sugar and 1 tablespoon lemon juice for every 3 cups of grape mash.

Mix the grape mash, sugar, and lemon juice together in a stainless steel stock pot. Bring the jam to a boil and then cook over medium heat until it gels.

If you have a lot of juice in the grape mash, it will take a long time, just be patient and let it cook. If you’re using mash that’s leftover from making grape juice, it won’t take as long since most of the juice is already extracted.

Stir the mixture often to keep it from sticking to the bottom of the pan, as the liquid evaporates its more likely that the jam will stick.

To test the jam to see if it’s going to gel when it cools, get one of the spoons you put in the freezer earlier. Dip the back of the spoon into the jam. Give it just a moment and then touch the jam, if it has gelled on the spoon it will gel in the jar when it cools off. If it’s still runny, it needs to cook down more.

Canning Grape Jam

While the jam is cooking down, prepare the water bath canner by filling it with water. You’ll need enough water so that the jars are completely covered by at least one inch water. Turn the heat on medium and put the lid on.

If you’re new to canning, here are some tips for water bath canning to help you out.

The jars and lids need to be washed in warm, soapy water and kept warm until filled with jam. I like to put the jars in the water bath canner until I need them.

There’s no need to sterilize the jars because they will be processed in the water bath for 10 minutes. But if you want to sterilize them by boiling them for 10 minutes, you can. If you have a dishwasher you can use that to clean the jars and keep them warm.

When the jam is cooked down and ready to be jarred, put the jars on a kitchen towel on the counter and ladle the hot grape jam into the hot jars. When the jars are full, wipe the rims with a damp cloth, and add the lids and bands.

There’s no need to put the bands on super duper tight, just put it on like you would put a lid on the mayonnaise before putting it in the refrigerator.

Put the filled jars in the water bath canner and turn the heat up. Once the water starts to boil, set the timer for 10 minutes adjusting for altitude – this is the processing time. And yes, it’s necessary in order to know that your safely canning the jam.

After 10 minutes remove the jars from the water bath canner and let them cool on a kitchen towel on the counter. The next day you can remove the bands and check the seals. Wipe down the outside of the jars and store in the pantry. If any of the jars didn’t seal, you can store them in the refrigerator and use them first.

I like to keep track of all my home preserved food so I know exactly what I preserved and how much we actually used that year. You can get a blank copy of these worksheets emailed to you by filling out the form below.

Thanks for sharing with your friends!