Mulberries for Jam

I’ve been curious about mulberries ever since I visited Dave Holderread’s waterfowl farm, about 25 years ago, and saw them planted in his duck pens. Dave explained that the trees would not only provide shade for the birds but would feed them without his intervention.

I wondered at this. Blackberries that grew on trees! Why didn’t more people plant mulberries? Why didn’t I plant a mulberry tree?

But I never identified a good place on the farm for a mulberry tree, and I certainly couldn’t make room for one when we moved to town. So I was delighted when my sister told me that my father’s mulberry tree. only a few years old, was producing heavily. That was in early July. A month later she told me that the tree was still producing loads of ripe fruit.

The other day I paid my father a visit. He, like Dave Holderread, had planted his mulberry tree to feed birds. But my father doesn’t keep ducks, or even chickens; he wanted to feed wild birds. He remembered a mulberry tree in the yard of a childhood home that had attracted all kinds of birds, whole flocks of birds. He had loved watching the birds eat the mulberries, and in his old age he wanted to repeat the experience.

The birds must have already had their fill for the day, because I didn’t notice any as I picked a pound and a half of mulberries for myself. I drove home with fingers stained deep purple.

The stains weren’t only on my fingers. Carrying the bag of mulberries into the house without removing my shoes, I noticed that my shoes were sticking to the floor, which now bore purple stains. The soles, I saw, were covered with mulberry gunk. I tried to rinse them in the kitchen sink, rubbing off the gunk with my fingers, but the water kept running purple. I scrubbed the soles with a sturdy brush to get the gunk out of the crevices. But immediately my shirt became covered with tiny purple-black dots. I felt like the Cat in the Hat with his pink bathtub ring. The water in which I was rinsing my shoes simply would not run clear, so I wrapped the shoes in a rag and set them outdoors to dry. Then I dropped my shirt in the sink and poured three kettlefuls of boiling water through the cloth. Sadly, the dots were much more stubborn than wine or blackberry stains. I gave up on the shirt, defeated by anthocyanins.

Black fruits from the species Morus nigra are considered the tastiest mulberries, but not all mulberries are black. M. rubra, native to the eastern states, is named for its red or purple fruit. M. alba, named not for its fruit but for its pale buds, can produce white or lavender as well as black berries. M. alba is the mulberry of East Asia, the original silkworm food (the caterpillars can also eat the leaves of other mulberry species). Although the West has long given up sericulture in favor of nylon and other synthetics, Europe and North America both had silk industries once, and for this reason the white mulberry is now a weed tree in Europe, much of Canada, and every U.S. state except Nevada (although, strangely, I have never seen one). M. alba is a promiscuous thing, crossing so often with the native M. rubra that some fear the red mulberry will soon no longer exist in its pure form. The heat-loving M. nigra, meanwhile, keeps to itself, not hybridizing with the other two at all. It will bear temperatures no lower than 0 degrees Fahrenheit.

There are other mulberry species, and many interesting cultivars within the species. One Green World Nursery sells a contorted mulberry, a weeping mulberry, a dwarf mulberry, and a mulberry from Pakistan with fruits as long as six inches.  Jim Gilbert, the nursery’s founder, has said he particularly likes ‘Illinois Everbearing,’ which although black-fruited is an alba-rubra cross. I suspect this is the cultivar my father has. It performs well not only in the Willamette Valley but throughout much of the country, to USDA zone 4. And the fruit is intensely tasty. Some compare the taste to blackberry and blueberry combined.

I stored my berries in the fridge overnight and, in the morning, clipped off their stems with kitchen shears. This is the only tedious part of processing mulberries, whose fine but tough stems are hard to pull out, easier to cut. Then I made the berries into jam in the usual way, by mashing the fruit and adding sugar and a little lemon juice. They need no added pectin.

Mulberry Jam

1½ pounds stemmed mulberries, rinsed
2 cups sugar
2 tablespoons lemon juice

First, put on an apron or, better yet, your painting clothes. Then put the mulberries into a preserving pan. Cook them over medium-low heat, crushing them with a potato masher, until they are tender. Remove the pan from the heat.

Add the sugar and lemon juice. Return the pan to the heat, and cook the mixture over medium heat until the sugar has dissolved. Raise the heat to medium high, and cook the jam to 218 degrees F, until a drop mounds in a chilled dish. This will take about 5
minutes.

Ladle the jam into sterilized pint or half-pint mason jars. Add lids and rings, and process the jars in a boiling-water or steam canner for 5 minutes.

Makes 1 ½ pints

This jam turns out distinct from blackberry jam, although the color and flavor are similar. The big difference is the seeds. Mulberries have more. Thankfully, mulberry seeds are small—too small to stick between the teeth—and they are pleasantly crunchy, like sesame seeds.

Mulberries are good for more than jam. The fresh ones are a treat. The fruit can be dried and—no surprise—used to make a dye. Both the leaves and the root bark are used medicinally.

Judging from the red and white immature fruits on my father’s tree, it will probably keep producing fruits for another two weeks or more. Who can resist a tree that produces huge quantities of fruit over such a long period, that brings birds to the garden, that grows to maturity quickly, that usually stays fairly small (‘Illinois Everbearing’ grows no taller than 20 feet), and that can take the form of a shrub, an espalier, and a contorted or weeping ornamental as well as an ordinary tree?

One warning, though: You should not plant a black-fruited mulberry near a walkway or in an area where children play, unless they are better trained than I to remove and clean their shoes before coming into the house.

Today I cleaned gobs of mulberry gunk off my car mat. Somehow, even the driver’s seat had acquired a few deep purple stains. They will probably be there forever.