For Winter Pies: Home-Canned ClearJel Filling

For at least fifteen years Extension agents have been urging home food preservers to try ClearJel, a kind of cornstarch used mainly in factory foods. Unlike regular cornstarch, ClearJel is made from waxy maize, a mutant variety discovered in China in 1909. The endosperm of this corn contains no amylose starch at all but in its place a substance called amylopectin, which turns the corn glutinous—that is, gluey—with cooking. Waxy corn is to regular dent corn as sticky rice is to long-grain rice.

In 1948 an American manufacturer used waxy corn to create ClearJel. Whereas regular cornstarch breaks down when exposed to high temperatures and acid foods, ClearJel does not. ClearJel withstands the heat of both canning and reheating.

Frankly, I have avoided this stuff. I can easily make a berry pie in winter, after all, by combining starch and sugar with berries from the freezer. Why would I can pie filling?

I answered that question myself last summer after stuffing half my freezer with Marionberries. I couldn’t spare any more freezer space for fruit. But I have two long rows of Marionberry vines in my garden, and the crop was especially heavy. What could I do with all the berries? Marionberries make rough, sour wine, so we prefer to make our blackberry wine from wild Himalayans. I could use some Marionberries in fruit leather or paste, but if I wanted to preserve more of the berries they would have to go into jars to be shelved in the garage.

I decided to try canning some pie filling with ClearJel. I bought a bagful of the stuff just a few miles from home at Nichols Garden Nursery. The store manager, Betty, made sure I got “regular” ClearJel, or ClearJel A, another name for the same thing. A different kind of waxy-maize cornstarch, called Instant ClearJel, is used without cooking; it isn’t intended for canning or heating of any sort.

Instructions for using ClearJel A vary. Nichols recommends substituting the same measure of ClearJel, or 10 percent less, for the regular cornstarch called for in a recipe. The Blue Chip Group, a bulk-food store in Utah, says to start by using half the amount of ClearJel as thickener called for in a recipe.

How much cornstarch do you put in a Marionberry or other blackberry pie? I wasn’t sure, because I usually use tapioca, not cornstarch, to thicken my berry pies. The cookbooks I consulted gave various recommendations, from 2 to 4 tablespoons cornstarch for 4 cups berries.

The Extension instructions call for 5 tablespoons ClearJel for only 3 1/3 cups fruit. But Extension’s ClearJel recipes seem odd in other ways. The blueberry, apple, and cherry pie-filling recipes call for food coloring—blue, yellow, red, or a combination—and the quantities of sugar are unusually high. I suspected these recipes were aimed at reproducing factory pies—the oversweetened, gluey, flat pies that come in throwaway foil plates. If I wanted one of those, I’d grab it out of the supermarket freezer case.

The 3 1/3 cups fruit called for in the Extension recipe also seemed wrong. What sort of pie would you make with so little fruit? Pie plates generally come in diameters of 9 and 10 inches—unless you use a throwaway foil plate, which is typically only 8 inches in diameter. Again, I suspected an urge to imitate a factory pie.

Could I make a berry pie I could be proud of with ClearJel?

I wouldn’t use too much of the stuff. I decided to average the recommended amounts for ordinary cornstarch—that is, I would use 3 tablespoons for 4 cups fruit.

And I decided to use the full 4 cups fruit, not 3 1/3 as in the Extension recipe. I needed 4 cups fruit, actually, to leave a headspace measurement of 1½ inches in the mason jar, as the Extension recipe called for. (I’m glad I didn’t try to use more than 4 cups, because a mixture of fruit and ClearJel expands so much with heating that a fuller jar would leak its contents during processing.)

The Extension instructions also call, strangely, for water—1 1/3 cups of it. Thankfully, the recipe says you can substitute juice for the water. I could have mashed some of the fruit, or macerated the berries in part of the sugar to draw out their juice, but easiest of all was substituting fermented juice—that is, wine. A case of Marionberrry wine was sitting in the garage somewhere, but I couldn’t find it, and so I used Himalayan blackberry wine instead. Cabernet or Merlot would have worked as well, I think. I used 6 tablespoons wine, an amount that seemed adequate, though it was only twice the volume of ClearJel I was using. The Extension recipe calls for more than four times as much liquid as ClearJel.

The pie filling shrank as the jar cooled after processing, leaving about 2 inches headspace. When the processed jar had cooled, the berries were covered in a clear, shiny, sauce that kept them in a mass when the jar was turned. The mass was loose, not solid as in a factory pie.

I tried the filling both baked in a two-crust pie and then straight from the jar in a baked sweet pie crust. Nobody complained about gooiness. I left the single-crust pie on the kitchen counter, and my husband and I ate it slowly, over five days. The filling neither soaked the crust nor attracted fruit flies. On the fifth day it was just as tasty as on the first.

So here’s my recipe for–

Marionberry Pie Filling with ClearJel

2/3 cup sugar
2 1/2 tablespoons regular ClearJel
½ cup Marionberry, blackberry, or red grape wine
4 cups Marionberries
½ teaspoon grated orange zest

In a pot, stir together the sugar and ClearJel. Add the wine, and, stirring constantly, bring the mixture to a boil. Boil the mixture for 1 minute, and then gently fold in the berries and the orange zest. Remove the pot from the heat.

Pack the mixture into a quart mason jar, making sure to leave 1 ½ inches headspace. Add a lid and ring, and process the jar in a boiling-water bath for 30 minutes (or 35 minutes, at more than 1,000 in elevation, or 40 minutes, at more than 3,000 feet.)

Use the filling in a two-crust 9-inch pie, and bake the pie as usual, or spread the filling in a baked 9-inch pie shell to serve without further cooking.

For a one-crust pie, I recommend using a pâte sablée, with sugar and egg yolk. You might add some grated lemon rind to balance the sweetness of the dough and filling, or spread a layer of lemon curd on the crust before adding the berry filling. Or you might serve the pie with crème fraîche or clotted cream.

Later I tried making the pie filling with Himalayan blackberries and juice from the same berries. Because Himalayan blackberries are relatively low in acid, I added 4 teaspoons lemon juice to the mix. Extra acid is needed in ClearJel pie fillings, according to the Extension instructions, to help stabilize the starch.

Peach tart with ClearJel
Peach tart with ClearJel

I also tried a peach pie filling with ClearJel. This time I used ¾ cup sugar for 4 cups fruit and 3 tablespoons ClearJel, and for liquid I used ¼ tablespoons lemon juice and 2 tablespoons apple juice. I also added a little grated nutmeg, about 1/8 teaspoon. Again I served the filling in a baked sweet crust. The filling turned out a little gooey for my taste; I’d prefer the pie with a top crust. But my friends liked it, and one remarked on how fresh and firm the peach slices remained after the processing they had undergone.

Some Mennonite-run grocery stores carry ClearJel, and your Extension home-ec agent may be able to identify other sources in your area. If not, you can buy ClearJel over the Internet from vendors such as Nichols, King Arthur, or Barry Farm.