Mulberries are an underappreciated fruit, often cursed by homeowners because when they're ripe, they can fall to the ground and make a mess on patios and walkways. Instead of allowing the berries to litter your outdoor space, why not harvest this delicious fruit and make jam? It's abundant enough that you should be able to harvest some for jam, eat some fresh, and freeze some for later.
The tricky thing is that mulberries don't all ripen at the same time. That's one of the reasons you'll rarely see them as a commercial crop—that, and the fact that they are delicate and don't ship well, which reduces their shelf life.
An easy way to harvest them is to lay down a ground cloth underneath the tree and shake the lower branches—the ripe berries will fall off onto the cloth. If you don't own any mulberry trees and don't have access to fresh mulberries, you can use frozen mulberries for this recipe.
Mulberries don't have enough pectin on their own, which is why you need to add pectin for this recipe to make sure the jam thickens and sets.
Gather the ingredients.
Sterilize the canning jars in boiling water.
While the jars are sterilizing, put the mulberries, sugar, and lemon juice into a large, nonreactive pot. (Do not use aluminum or nonenameled cast iron as these can create off colors and flavors in your jam; stainless steel or enameled cast iron are fine.)
Bring the mixture to a full boil over high heat, stirring constantly to prevent scorching and to help the sugar dissolve.
Once the mixture has come to a full boil and the sugar is completely dissolved, add the pinch (a couple of scrapes on a grater) of freshly ground nutmeg.
Add the liquid pectin. Boil for 1 minute while stirring constantly. Remove from the heat.
Skim off any foam that may have formed on the surface of the jam.
Ladle the jam into the sterilized canning jars, leaving 1/2 inch of headspace. Wipe the rims of the jars with a clean damp cloth or paper towel.
Secure the canning lids, and process in a boiling water bath for 5 minutes.
Remove the jars from the water bath using a jar lifter or tongs. Set on a cooling rack or towels 1-inch apart. Let cool completely without disruption for 12 to 14 hours. The lids will pop or ping as they seal.
Test the seal by pressing down on the center of the lid; it should feel solid. If you remove the ring, the lid should not come off. Any jars that fail should be refrigerated and eaten right away or, if it has been less than 24 hours since canning, reprocessed with a new lid (and jar, if necessary).
Store in a dark, cool place for up to 1 year. Enjoy.
How Do You Get the Stems Out Of Mulberries?
If you have harvested your own berries, follow these steps to prepare them for making the jam. Even very ripe mulberries usually come off of the tree with a little bit of stem attached. It is a bit of work to remove the little stems, so it's up to you whether to take the time, but if you do, your jam will have a better texture.
- First, you need to remove any leaves, sticks, and unripe (pink) berries from the bunch. (Don't eat any of the pink berries as they can make you sick.)
- Next, you need to wash the mulberries. Place them in a colander and rinse well with water, or put the berries in a sink or bowl of water, and then drain well in a strainer.
- Treat them gently so you don't squish them and release their juices. Now you are ready to cook them down into jam.
Mulberries are a low pectin fruit, and the downside of this is that commercial pectin requires a lot of sugar to produce a gel. If you'd like to avoid using liquid pectin, you can combine the mulberries with a high pectin fruit such as apples, pears, oranges, and gooseberries. For a lower-sugar option, try using low-methoxyl pectin. You may also want to try mulberry jam made with homemade pectin.
The canning process makes the most sense when you have a large amount of jam—too much to eat in the near future and over a short period of time. But mulberries aren't sold in large quantities and ripen at different rates, so you may not have enough. If that's the case, it's just not worth it to go through the canning process. Simply spoon the cooked and cooled jam into small containers and freeze. Thaw as needed. It should keep for at least a year.