Apple Pie Filling: Homemade, Firm Slices, Bake, Freeze or Can

Choose the thickener by what happens next: bake, freeze or can

Most recipes for apple pie filling give you one cornstarch slurry and stop. That is the right answer for exactly one situation. The starch that works depends on what the filling will go through after it leaves the pot, and the three common plans need three different starches.

Baking or eating it within a few days: cornstarch. It is cheap, it is in every kitchen, and apples need less of it than any other pie fruit, because they are less juicy and naturally high in pectin. King Arthur Baking’s thickener chart gives 1/2 tsp of cornstarch per cup (240 ml) of sliced apples, or 1 tbsp plus 1 tsp for a 9-inch (23 cm) pie. This recipe uses that same 1 tbsp plus 1 tsp, about 10 g, for 2 1/4 lb (1 kg) of prepared slices, which is about 1% of the apple weight. It can be that low because the juices are reduced first. If you prefer flour, the same chart gives roughly three and a half times the cornstarch amount, and the result is cloudier with a faint floury taste. Flour must be boiled with the filling just like the cornstarch; never stir raw flour into a filling off the heat.

Freezing it: tapioca starch (often sold as tapioca flour) or Instant ClearJel. Penn State Extension is direct about why: “Freezing causes liquids thickened with flour or cornstarch to shear or separate.” A cornstarch gel tightens as it sits cold and squeezes water back out, and freezing and thawing makes that much worse, so the thawed filling sits in a puddle. Tapioca holds on to its water. Use 2 1/2 tbsp of tapioca starch, about 16 g, for this batch, which is 1.6% of the apple weight and in line with the dose pastry chef Stella Parks uses in her apple pie. Instant ClearJel, a modified starch that thickens without cooking, also freezes well; King Arthur’s dose is the same as for cornstarch, 1 tbsp plus 1 tsp for a pie. If you use it, hold back 1 tbsp of the granulated sugar in step 2, mix the Instant ClearJel into it so it does not clump, and sprinkle it over the filling while folding, once the pot is off the heat.

Canning it: cook-type Clear Jel, and nothing else. Clear Jel (the trade spelling is Clearjel) is a modified waxy maize starch that home-canning guidance specifies for fruit pie fillings. It is rarely on supermarket shelves on either side of the Atlantic and is usually bought online or from canning suppliers. The two versions of the product are mirror images: cook-type is for canning and not recommended for freezing, and instant is for the freezer and not for canning. Canning also needs its own recipe, with far more starch and added liquid than a stovetop filling, so it is covered separately below.

Two more points apply whichever starch you pick. First, starch is the last line of defense, not the first. In his testing for Serious Eats, J. Kenji López-Alt found that doubling the cornstarch in a runny pie “works, but you end up with a goop-to-apple-chunk ratio that’s way off base”; cooking the juices down was the better fix. Second, sugar and acid both get in the way of starch, so in a sweet, tart syrup the slurry needs a real, visible bubble for a full minute. Warm is not enough.

Why a gentle hold keeps the slices firm (and who worked out the numbers)

It sounds backwards that cooking apples twice makes them firmer than cooking them once, but it is well documented. Apples contain an enzyme, pectin methylesterase, that modifies the pectin holding their cells together so that calcium already present in the fruit can cross-link it into a tougher, heat-stable network. The enzyme does almost nothing at room temperature, works hard when the fruit is warm, and is destroyed when the fruit gets hot. Give it time in its working range and the slices are armored before the real cooking starts.

The numbers most cooks use are the ones J. Kenji López-Alt printed at Serious Eats: hold the apples between 140 and 160°F (60 to 71°C) for around 10 minutes, and be aware that apples whose pectin has not been set start to fall apart at about 183 to 185°F (84 to 85°C). He baked par-cooked and raw slices side by side and reported that the par-cooked ones stayed intact while the raw ones cooked down toward applesauce. The idea is not his, and he says so. The technique of gently pre-cooking pie apples was popularized by Cook’s Illustrated and America’s Test Kitchen, whose deep-dish apple pie explains that “When the apples are gently heated, their pectin is converted to a heat-stable form that keeps them from becoming mushy when cooked further in the oven.” A 2005 Cook’s Illustrated sidebar on shrinking pie apples gave the enzyme explanation and a low-heat ceiling, telling readers to keep the apples below 140°F (60°C) while they pre-cook in a covered Dutch oven. López-Alt credits the magazine for the explanation and for the rule of staying close to, but not above, 160°F (71°C). The 140 to 160°F range, the 10 minutes and the 183 and 185°F figures are in his wording, and his range is the one this recipe follows.

The laboratory numbers agree with the kitchen ones. A 2000 study of the enzyme purified from Golden Delicious apples (Denès, Baron and Drilleau, Journal of the Science of Food and Agriculture) put its optimum temperature at 63°C (145°F), which sits squarely inside the 60 to 71°C window. That figure was measured on the purified enzyme, not inside a slice of apple, so read it as support for the window and not as a setting to aim for. Food scientists have used the same trick, a low-temperature hold before high-heat processing, to keep canned and frozen vegetables firm for decades.

There is an honest caveat that recipe pages leave out: the hold does not help every apple equally. A 2016 study of apples cooked sous vide found the enzyme up to twice as active in Mondial Gala as in Granny Smith between 48 and 65°C (118 and 149°F), which overlaps the lower half of the window. In practice, the hold pays off most on sweeter dessert apples such as Gala, Golden Delicious and Braeburn. Granny Smith holds its shape mainly through its acidity and gains the least, though the hold does it no harm.

If you do not own a thermometer, López-Alt’s other method needs none, because a measured amount of boiling water sets the temperature for you. His ratio is 3 quarts (2.8 litres) of boiling water for 4 to 4 1/2 lb (1.8 to 2 kg) of whole apples, which scales to 2 1/2 quarts (2.4 litres) for this batch. Put the room-temperature slices in a large heatproof bowl or pot, pour the measured boiling water over them, cover and leave for 10 minutes, then drain in a colander for about 10 minutes, tossing now and then, until the slices are dry. The amount matters: measured this way, he reports, the apples sit at around 160°F (71°C), while more water would run hotter and less would run cooler. He tested it on slices 1/4 inch (6 mm) thick; thicker wedges warm through more slowly, so the thermometer method is the surer one for this recipe. Use a bowl that is stable and made to take boiling water, and drain it away from you. Then toss the drained slices with the sugar and spices and carry on from the reduction step; there will be less juice to cook off, so it will take less time.

The best apples for pie filling, in the US and in Europe

The rule is short: tart and dense holds its shape. Acid strengthens pectin, and a dense apple with little air between its cells has less room to collapse. In the best-known American side-by-side test, López-Alt baked ten supermarket varieties in pies and scored Golden Delicious 8 out of 10, Braeburn 7, Gala 6 and Granny Smith 5 (it held its shape almost indefinitely but tasted less of apple), with McIntosh at 3, Fuji at 2 and Red Delicious at 1. The home-canning guidance from the National Center for Home Food Preservation asks for “firm, crisp apples” and names Stayman, Golden Delicious and Rome.

That test covered American supermarket apples only, and readers elsewhere are left to guess. Measured data helps. In one Austrian laboratory comparison of European cultivars, Roter Boskoop (Belle de Boskoop) was the most acidic by a wide margin, at about 13 g of malic acid per litre with a firmness of about 7.2 kg on a penetrometer, while Braeburn was the firmest, at about 8.9 kg, with moderate acidity of about 7.6 g per litre. Cox’s Orange Pippin was tart, at about 9.9 g per litre, but soft, at about 5.4 kg, and Elstar was softer still, at about 5.2 kg, with acidity of about 7.8 g per litre, no higher than Braeburn’s. Read together: Boskoop holds through acid, Braeburn holds through density, Cox is a flavor apple that cooks down, and Elstar, the softest of the four, belongs with Cox and not with the firm bakers.

Storage matters as much as variety. In a South Tyrol trial of commercial cultivars, Granny Smith measured 7.7 kg at harvest and still 7.4 kg after two months of cold storage, a loss of about 4%, while Jonagold fell from 6.5 kg to 4.7 kg, a loss of more than a quarter. Granny Smith was also the most acidic commercial apple in that trial at about 10.3 g per litre. That is why Granny Smith is the safe year-round supermarket choice and why Jonagold and Golden Delicious are at their best for baking in autumn, soon after harvest. These figures come from different orchards, years and laboratories, so compare apples within one study, not across them.

What to buy. In the US: Granny Smith with Golden Delicious or Braeburn, or Pink Lady on its own. In Europe: Boskoop with Braeburn or, in autumn, Jonagold, or Granny Smith with Braeburn the rest of the year. Opinions on mixing differ: López-Alt and Stella Parks both argue for a single variety so every slice cooks at the same rate, while other bakers like one tart apple and one aromatic one. The position that satisfies both is to blend only apples that are all firm bakers and never to pad the pot with a soft variety such as McIntosh.

A word on Bramley, the classic British cooking apple. It is very acidic, yet it famously “falls” to a fluffy purée when cooked, so it is the exception to the acid rule. Use it if you want a traditional soft British filling, or blend it half and half with a firm apple, but do not expect distinct slices from Bramley alone.

How much filling a 9-inch (23 cm) pie takes, and how to bake it

Recipes that call for “5 apples” are not much help, because apples vary a great deal in size. Work by weight. One pound (454 g) of whole apples loses about a third to peel and core and gives roughly 10 oz (285 g) of prepared fruit, about 3 cups (700 ml) of thin slices. King Arthur Baking’s standard for a raw-filled 9-inch (23 cm) pie is 8 cups (1.9 litres) of slices, from about 2 2/3 lb (1.2 kg) of whole apples.

A pre-cooked filling changes the sums, because the shrinking happens in the pot instead of in the oven. Pastry chef Stella Parks measured sliced apples losing about a third of their volume as they give up their juice to sugar alone. Cooked and reduced on the stove they lose more, closer to half. In a raw pie the pastry lid sets early in the bake while the fruit underneath is still tall, then the fruit sinks and leaves the familiar hollow under the crust. Cooked filling has already shrunk, so it packs in level, the lid sits on the fruit, and you can fit more apple into the same dish. This recipe starts with 3 1/2 lb (1.6 kg) of whole apples for that reason, and ends as 4 to 4 1/2 cups (1 to 1.1 litres) of dense filling, roughly 2 1/4 to 2 1/2 lb (1 to 1.1 kg), which fills one standard 9-inch (23 cm) pie plate level with the rim. For comparison, the usual advice for canned filling is two 21 oz (595 g) cans for a 9-inch (23 cm) double-crust pie, which is a similar amount.

Scaling: for a deep-dish 9-inch (23 cm) pie, make one and a half batches, from about 5 1/4 lb (2.4 kg) of whole apples, which gives roughly 6 to 7 cups (1.4 to 1.7 litres). For an 8-inch (20 cm) pie, three quarters of a batch is enough. When you scale up, use a wider pot rather than a deeper pile, so the hold stays even and the juices can still reduce in about 10 minutes.

To bake it in a pie: line the plate with cold pastry, spread the completely cooled filling in level, top with a pastry lid, lattice or crumble, and cut vents in a solid lid. A workable schedule for a pre-cooked filling, a little longer than the one López-Alt gives for his own pie, is 425°F (220°C) on a lower-middle rack for about 25 minutes to set the bottom crust, then 375°F (190°C) for 25 to 30 minutes more, until the pastry is deep golden and you can see the filling bubbling at the vents. Cover the rim with foil if it colors too fast. Because the apples are already cooked, you are baking the pastry and reheating the filling, not cooking the fruit. Let the pie cool for several hours before you cut it, because the filling sets as it cools. Pastry, assembly and the full bake will get their own pages.

Make-ahead: fridge, freezer and the one tested way to can it

Popular recipes give 2, 3, 4 and 5 days for the fridge and 2, 3 and 6 months for the freezer, with no reasons. Here is one position with its sources. In the fridge, treat the filling as a cooked leftover: 3 to 4 days at 40°F (4°C) or below under the USDA’s general rule, or 2 days if you follow the UK Food Standards Agency’s stricter advice. The syrup stiffens when cold; fold it gently before using and it loosens again.

In the freezer, make the tapioca version, cool it, and freeze one pie’s worth in a bag pressed into the pie plate, as Penn State Extension recommends. To bake, set the frozen disc straight into a raw pastry shell, add the lid and bake as usual; Penn State Extension says to allow an extra 20 to 25 minutes. No thawing is needed for pie. For anything else, thaw it overnight in the fridge and use it within a day. For best quality, use frozen filling within 3 to 4 months. If you already froze a cornstarch filling and it has wept, it is safe; warm it gently in a pan to tighten the syrup again.

Canning is a different recipe, not a different storage option, so follow the tested National Center for Home Food Preservation (NCHFP) procedure and nothing else. What follows is a summary so you can see how different it is, not a set of instructions to can from. Work from the NCHFP’s own apple pie filling page and its guide to using a boiling-water canner, which cover jar preparation, lids, water depth, timing and seal checks that are not repeated here. The tested formula, adapted from the USDA Complete Guide to Home Canning, makes one quart (0.95 litre) jar from 3 1/2 cups (830 ml) of blanched apple slices, 3/4 cup plus 2 tbsp (about 175 g) of granulated sugar, 1/4 cup (60 ml) of cook-type Clear Jel, 1/2 tsp cinnamon, 1/2 cup (120 ml) of cold water, 3/4 cup (180 ml) of apple juice and 2 tbsp of bottled lemon juice. The slices are blanched in batches of 6 cups (1.4 litres) in 1 gallon (3.8 litres) of boiling water, for 1 minute counted from when the water returns to a boil, then drained and kept hot in a covered pot. The sugar, Clear Jel, cinnamon, water and juice are cooked until thick and bubbling, the lemon juice is added and boiled for 1 minute with constant stirring, and the hot apples are folded in. The jars are filled without delay, leaving 1 inch (2.5 cm) of headspace, then the lids are adjusted and the jars are processed immediately.

Processing times in a boiling-water canner, for pints or quarts: 25 minutes up to 1,000 ft (305 m) above sea level, 30 minutes from 1,001 to 3,000 ft (306 to 914 m), 35 minutes from 3,001 to 6,000 ft (915 to 1,829 m), and 40 minutes above 6,000 ft (1,829 m). Follow the full procedure on the NCHFP website, not this summary, and do not change the jar size, the starch or the quantities, apart from the extra lemon juice the NCHFP page itself allows for apples that are not tart: the times were validated for that exact density. Bottled lemon juice is specified because its acidity is standardized. Butter and other fats are not part of the tested recipe.

Why Clear Jel and only Clear Jel? Elizabeth Andress of the University of Georgia, who directed the National Center for Home Food Preservation, wrote that it “does not break down in the acid food mixtures and does not thicken enough during heat processing to interfere with the intended effect of the heat on killing bacteria during canning.” The sauce stays thin while the jar heats and thickens as it cools. The canned version trades some texture for shelf life: its apples are blanched at a full boil, the opposite of the gentle hold, and it carries much more starch and sugar. If firm slices are the goal and you have freezer space, freeze.

Pre-cooked filling is older than the can, and older than America

Cooking the apples before they meet the pastry feels like a modern test-kitchen trick. It is one of the oldest ways of making the dish. The recipe usually cited as the first English apple pie, “For to make Tartys in Applis”, reads in full: “Tak gode Applys and gode Spycis and Figys and reysons and Perys and wan they are wel ybrayed colourd wyth Safroun wel and do yt in a cofyn and do yt forth to bake wel.” The fruit is “ybrayed”, pounded in a mortar, so this was a spiced paste of apples, figs, raisins and pears, colored with saffron, in a pastry case. No sugar is named. Most pages that quote it say it comes from the Forme of Cury. It does not. It is recipe XXIII in a separate manuscript that Samuel Pegge printed as an appendix to his 1780 edition of the Forme of Cury, under the heading “Ancient Cookery. A.D. 1381”, a date taken from a neighboring text in the same manuscript.

A Dutch cookbook printed in Brussels around 1514, Een notabel boecxken van cokeryen, has an “Appeltaerten” that works the other way round: the apples are peeled, cut small and baked raw under a pastry lid, then the lid is cut open, the fruit is stirred to a mash with a wooden spoon and mixed with grains of paradise, ginger, cinnamon, nutmeg, cloves, mace and sugar. For a richer tart the cook adds crumbled sugar cakes and cream and returns it to the oven to dry. The English cookery writer Hannah Glasse, in the first edition of The Art of Cookery in 1747, layered raw quartered apples with sugar and lemon, then boiled the peels and cores with a blade of mace, strained the liquid and boiled it down with a little sugar “till there is but very little and good” before pouring it into the pie. She does not say why, but peels and cores are where much of an apple’s pectin sits, so her syrup did some of the job that starch does now.

The first cookbook written by an American, Amelia Simmons’s American Cookery of 1796, prints both methods side by side. Her “Apple Pie” begins “Stew and strain the apples”, a pre-cooked purée flavored with lemon peel, cinnamon, mace and rose-water. Her “buttered apple Pie” bakes raw quartered apples and seasons them afterwards by lifting the lid. Fannie Farmer’s Boston Cooking-School Cook Book of 1896 already has a filling any modern make-ahead cook would recognize: apples baked covered “three hours in very slow oven, when apples will be a dark red color”, then, in her words, “Cool, and bake between two crusts.” Neither Simmons nor Farmer thickens apple pie with anything at all.

The can came much later, and nobody can honestly name its inventor. The Comstock brand claimed first use of its name in 1931 in a later trademark filing, and the earliest dated advertisement found for its canned “Pie-Sliced Apples” ran in Woman’s Day in September 1944, but neither fact shows a ready-to-use filling. The best dated statement is from a 1960 Canadian government bulletin on the subject, which opens: “Canned ready-to-use fruit pie fillings are not new products having been on the market since about 1946.” The Wilderness brand’s trademark record gives a first use of May 1950. Clear Jel reached the home canner later still. The USDA’s Complete Guide to Home Canning, developed at Penn State, was first published in 1988, and it is reported secondhand that a canned apple pie filling was the first approved home-canning recipe to use the starch; that could not be checked against the 1988 guide itself.

As for the saying, “as American as apple pie” has been found as early as October 1910, in a Metropolitan Magazine review that called a new play “as American as apple pie”, a citation reported by the word historian Barry Popik and, independently, by the researcher Peter Jensen Brown. It appears again on 4 April 1920, when Edwin C. Hill, writing about the circus in The Sun and the New York Herald, referred to “ideas as American as apple pie.” The 1924 suit advertisement often given as the origin is simply the earliest example in the Oxford English Dictionary, as Popik has documented. The apples, the pastry and the recipe all crossed the Atlantic first.

Beyond pie: what to make with apple pie filling

A filling with firm slices and a glossy syrup is a finished dessert component, which is why it is worth making even when no pie is planned. Warm it gently in a small pan and it is ready to plate.

Baked: hand pies and turnovers (chop the slices smaller first so they fit), a crumble or crisp (the filling is already sweetened, so cut the sugar in the topping), a cobbler, filled puff pastry squares, or a layer in an apple strudel or a bread-and-apple pudding. Unbaked: spooned warm over vanilla ice cream, pancakes, waffles, French toast, porridge or thick yogurt; layered into a trifle or a parfait with crushed biscuits; or served cold beside a wedge of sharp cheddar.

It also belongs on the savory side of a holiday table. A spoonful of warm filling, made with the smaller amount of cinnamon, sits well next to roast pork or a pork chop, and on a Thanksgiving table it can stand in for apple sauce. One batch equals roughly two 21 oz (595 g) cans in any recipe that calls for canned apple pie filling.