Scalloped Potatoes Recipe: Creamy, Never Curdled or Hard

What makes these scalloped potatoes different

Scalloped potatoes are thinly sliced potatoes baked in cream and milk until the slices are soft, the sauce is thick and the top is golden. They are the side that sits next to the ham at Easter and the turkey at Thanksgiving and Christmas, and they fail in two famous ways: the middle stays crunchy, or the sauce curdles into grainy puddles.

This homemade scalloped potatoes recipe avoids both by changing where the cooking starts. The slices go straight from the mandoline into seasoned cream and milk and simmer on the stove until almost tender, so the potato’s own starch thickens the sauce and protects it before the dish ever reaches the oven. There is no roux and no flour, which also makes it naturally gluten-free. Then it bakes at a gentle 350°F (175°C) for about 35 minutes instead of the hour and a half that raw-layered versions need.

You get one 9x13 inch (23x33 cm) dish that serves 10: 4 lb (1.8 kg) of Yukon Golds, 2 1/2 cups (600 ml) of heavy cream, 1 1/2 cups (360 ml) of whole milk, a sweated onion, garlic, nutmeg and thyme. Make it as the no-cheese classic, which is what “scalloped” traditionally means in the US, or layer in 6 oz (170 g) of Gruyère, which technically makes it potatoes au gratin. The salt is given in grams, because the same spoonful of kosher salt can differ by 70% between brands.

It is also the most make-ahead-friendly side on a holiday table. You can assemble it the day before and bake it cold, bake it fully and reheat it, or freeze it, and each of those has a different clock, set out below with US and UK windows. And the history is not the one you have read elsewhere: the first scalloped potatoes were mashed, and the famous 1788 “gratin dauphinois” record says neither “dauphinois” nor “potatoes”.

Scalloped potatoes vs au gratin: the honest answer

The short answer: in the US today, scalloped potatoes are thin potato slices baked in cream or milk with no cheese, and potatoes au gratin add cheese, often with breadcrumbs, for a browned crust. That is the modern convention, and it is how this page labels its two versions.

Two common add-ons to that answer are wrong. The first is that scalloped potatoes use a flour-and-butter roux and au gratin use cream. Plenty of classic scalloped potatoes use no flour at all: America’s Test Kitchen relies on heavy cream lightened with milk, and Martha Stewart calls making a cream sauce “overcomplicating the dish”. The method and the name are independent. The second is that “gratin” means cheese. It means the browned crust (from the French gratter, to scrape), and the French original, gratin dauphinois, is usually made without cheese.

The cheese rule is also younger than it sounds. In Fannie Farmer’s Boston Cooking-School Cook Book of 1896, “Potatoes au Gratin” are creamed potatoes covered with “buttered crumbs”, with no cheese at all. The very next recipe reads: “Delmonico Potatoes. To Potatoes au Gratin add one-third cup grated mild cheese”. So in 1896 cheese made a different dish. In 1960 Betty Crocker test-marketed boxed Scalloped Potatoes and Au Gratin Potatoes as two separate products. Whether that helped fix today’s naming split is our guess; no source says so, and today’s Scalloped box contains some cheese too.

Slice thickness is sometimes given as a difference too (thicker for scalloped, thinner for au gratin), but recipes on both sides range from 1/16 to 1/4 inch (1.5 to 6 mm). What matters is that the slices are even. Our Gruyère version is au gratin by the American convention, and we say so; the classic is the same recipe with the cheese left out and a little more salt.

The three methods compared, and a bake table

Almost every scalloped potatoes recipe uses one of three methods, and the method, not the oven setting, decides how long it takes and how likely it is to fail.

1. Simmer the slices in the dairy, then bake (this recipe; Martha Stewart; America’s Test Kitchen; Serious Eats slices into hot dairy too). The potatoes start the bake hot and partly cooked, the released starch has already thickened and stabilized the sauce, and you can taste the seasoning before it is locked in. It is the fastest and most predictable. Martha’s version scored 9.5 out of 10 in The Kitchn’s four-recipe test. The only cost is one extra pot.

2. Pour a flour-and-butter white sauce over raw layers (Tastes of Lizzy T), or dredge each raw layer with flour and butter and pour hot milk over (Allrecipes, and Fannie Farmer in 1896). The flour makes an all-milk sauce stable and keeps the fat down, which is why it suits a lighter dish, but it can taste pasty, and raw slices in a full 9x13 inch (23x33 cm) dish need an hour or more.

3. Parboil the slices in water, then bake in a white sauce (King Arthur Baking: boil 1 minute, drain, layer with a milk roux). The parboil evens out the start, but the water carries away starch that would otherwise thicken the sauce, so the roux has to do that job.

A fourth, the French way, layers raw slices in cream alone: it gives the most elegant layers and the longest bake, and it is the one most likely to curdle if the dairy is lean or the oven is hot.

How long at 350°F (175°C) or 375°F (190°C)? By method, from the recipes that tested them:

Simmered in the dairy until almost tender (this recipe): 350°F (175°C), uncovered, 30 to 40 minutes. America’s Test Kitchen bakes its 3 qt (2.8 L) gratin dish about 20 minutes.

Brought to a boil in the dairy and simmered 1 minute (Martha Stewart): 375°F (190°C), 35 to 40 minutes loosely covered, then 3 to 5 minutes under the broiler.

Par-cooked and refrigerated up to 24 hours (America’s Test Kitchen): 400°F (200°C), 45 minutes covered, then about 30 minutes uncovered.

Raw 1/16 inch (1.5 mm) slices in hot infused dairy, 2 qt (1.9 L) dish (Serious Eats): 350°F (175°C), 60 minutes covered plus 15 to 20 uncovered, then a 30-minute rest.

Raw slices under a white sauce, 9x13 inch (23x33 cm) dish (Tastes of Lizzy T): 400°F (200°C), 40 minutes covered plus 15 to 20 uncovered.

Parboiled in water, milk roux, 9x13 inch (23x33 cm) dish (King Arthur): 350°F (175°C), 1 hour uncovered.

Raw layers dredged with flour, warm milk poured over (Allrecipes): 375°F (190°C), 45 to 60 minutes.

Raw layers in plain milk, low and slow (Sara Moulton’s anti-curdle method): 350°F (175°C), about 2 hours, covered for all but the last 15 minutes.

Whatever the method, the finish line is the same: a paring knife slides through the center with no resistance.

Why scalloped potatoes stay hard or curdle (and how this method fixes both)

Potatoes that stay hard have four usual causes, roughly in order of impact. First, a deep dish. Heat travels into a dish of potatoes by conduction, and conduction time grows with roughly the square of depth, so a dish twice as deep can take close to four times as long to cook in the middle (once the sauce is simmering, convection helps, so treat this as a direction rather than a formula). For a crowd of 20, bake two 9x13 inch (23x33 cm) dishes, not one deep pan. Second, cold dairy poured over raw slices, which spends much of the bake just warming up; Serious Eats found that skipping the pre-heated milk can add up to half an hour. Third, acid and calcium. Potato cells soften when heat breaks down the pectin that glues them together, and acid slows that down; the food scientist Shirley Corriher’s advice is to cook potatoes in cream or milk and stir in sour cream only after they soften. Calcium in hard water firms pectin too. America’s Test Kitchen adds 1/4 tsp baking soda to its buttermilk scalloped potatoes to help the slices soften. Fourth, and less proven, a long stall at warm temperatures: potatoes held between about 122°F and 158°F (50°C and 70°C) switch on an enzyme that firms their cell walls, and a deep dish of cold cream spends a long time in that range. That is our inference from lab studies on potatoes, not a gratin test.

Starting the slices in simmering dairy removes the first three problems in one move: the potatoes are already hot and nearly tender when they go in, and they pass through the firming range on the stove in minutes. If your dish is still hard at the stated time, cover it and keep baking in 15-minute rounds at the same temperature. Turning the oven up is how a hard dish becomes a curdled one.

Curdling is milk protein clumping, and acid is the main trigger. As the food scientist Harold McGee put it in a 2010 NPR interview, milk proteins “are resistant to heat but very sensitive to acidity”. Fat protects: in cream of about 25% fat or more, there are enough fat globules to coat the proteins before they clump. Our dairy mix is just under that line (2 1/2 cups (595 g) of 36% cream holds 215 g of fat and 1 1/2 cups (366 g) of whole milk 12 g, so 227 g of fat in 961 g of dairy, 23.6%), and the unrinsed potato starch covers the rest: starch molecules physically get between the proteins. Onion pushes the other way: the 1946 Journal of Dairy Science study in step 2, which heated skim milk with filtered, clear vegetable extracts, found onion extract cut its heat stability by about 90%, which is why the onion is sweated first. Potato extract lengthened it by about 60% in the same test, but because the extract was filtered, that tells us nothing about the starch. The other triggers are a hot oven, low-fat milk used alone without a starch binder, and pre-shredded cheese, whose anti-caking coating can seize.

Watery scalloped potatoes have their own three causes: waxy or new potatoes that shed water, rinsed slices that have lost their thickening starch, and cutting the dish before it has rested for 20 minutes.

Which potatoes, and why you should never rinse them

The usual advice sorts potatoes into waxy and starchy and explains the difference with amylose and amylopectin. The chemistry is oversimplified. Ordinary waxy-textured potatoes are not “all amylopectin”: a 2025 study in Scientific Reports measured 24.7 to 27.5% amylose in waxy-textured cultivars against 29.5 to 33.0% in mealy ones. What really drives texture is how much starch (dry matter) the potato holds, which growers measure as specific gravity. Oregon State University’s bands read a specific gravity of 1.070 to 1.079 as waxy and 1.080 to 1.089 as mealy and dry.

By that measure Yukon Gold sits near the bottom of the waxy band (it averaged 1.071 over 20 Florida growing seasons), though cooks treat it as all-purpose, and Russet Burbank typically runs higher, about 1.08 (1.078 averaged across 18 US trial sites), right at the line between the two bands. When cooked, russet cells become completely engorged with gelatinized starch, so more of it leaks into the cream: the sauce gets thicker and the slices softer and more likely to break. Yukon Golds hold neat, visible layers and taste more buttery, which is why this recipe uses them; half Yukon and half russet is a good compromise if you want a looser, creamier sauce. Avoid red and new potatoes, which release water and can leave the dish thin.

Do not rinse or soak the slices. The starch on their surface is the thickener in a no-roux recipe, and Martha Stewart’s test kitchen notes that rinsing also makes the potatoes more watery. Browning is solved by where the slices go, not by water: as Serious Eats puts it, slicing them “directly into the milk they’ll be baked in” prevents oxidation “while keeping all their starches right where you want them”. The minority advice to rinse to avoid gluey potatoes applies to slices baked without enough liquid between them; the fix there is more dairy, not less starch.

Make-ahead scalloped potatoes: three tiers and their clocks

Tier 1: assemble a day ahead, bake on the day (best for the holiday oven). Follow the recipe through the simmer. To cool it fast, set the metal pot in a sink of cold water for about 10 minutes, turning the slices gently once (never do this with a hot glass or ceramic dish, which can crack), then layer it into the dish, press parchment or plastic wrap onto the surface so no potato is exposed to air, cover, and refrigerate within 2 hours of cooking, for up to 24 hours. For the Gruyère version, layer in half the cheese now and keep the rest for the top. Remove the plastic and bake straight from the fridge (no counter time to take the chill off) at 400°F (200°C); if your dish is glass, put it only into a fully preheated oven. Bake covered with parchment and then foil (so nothing sticks) for 45 minutes, then uncovered (lift the foil away from you; trapped steam burns), with the remaining Gruyère scattered over, for about 30 minutes, America’s Test Kitchen’s timing for a chilled, par-cooked dish, until bubbling, golden, knife-tender, and at least 165°F (74°C) in the center. Many online recipes say an assembled dish keeps 3 days; the test kitchens that give a window say one day, and uncooked slices held that long turn gray. Par-cooked, chilled potatoes can also firm up slightly (cooling strengthens the pectin between cells, per potato-processing research), so trust the knife, not the clock.

Tier 2: bake it fully and reheat. Cool, portion into shallow containers, and refrigerate within 2 hours. Keep up to 3 to 4 days (USDA) or 48 hours (UK FSA). Reheat covered at 325°F (163°C) with a splash of milk until the center reaches 165°F (74°C): about 20 minutes for a single portion, 45 to 60 minutes for a full dish, uncovering for the last 5 minutes to re-crisp the top. Reheat once.

Tier 3: freeze. It is safe, but it costs texture. USDA lists cream sauces among foods that do not freeze well, and potatoes can turn soft and grainy. A cream-heavy version like this one holds up better than a milk version. Bake it until almost done, cool, wrap well, and freeze for up to 3 to 4 months for best quality. Freeze it in a metal or foil pan, or thaw a glass dish in the fridge overnight before it goes into a fully preheated oven; a frozen glass dish in a hot oven can shatter. Reheat from frozen, covered, at 325°F (163°C) until it reaches 165°F (74°C), stirring the sauce back together at the edges if it looks split, and reheat it only once (UK FSA).

A holiday timeline: simmer and layer the day before. On the day, take the dish straight from the fridge into the oven about 1 3/4 hours before dinner: 45 minutes covered and about 30 uncovered at 400°F (200°C), plus the 20-minute rest and a few minutes’ slack. Do not leave it on the counter to take the chill off while the roast cooks. If it has to share a 325°F to 350°F (163°C to 175°C) oven with the roast, put it in earlier and keep it covered for longer, then uncover and finish at 400°F (200°C) while the roast rests, checking the center with a knife and for 165°F (74°C).

The history: shells, mashed potatoes and a Grenoble catering bill

“Scalloped” comes from the shell. The Oxford English Dictionary derives the cooking verb from the noun scallop, with its first evidence in 1737, and Merriam-Webster defines it as “to bake in a sauce usually covered with seasoned bread or cracker crumbs”, explaining it comes “from the use of a scallop shell as a baking dish”. Food was baked and served in scallop shells long before potatoes were: Robert May’s Accomplisht Cook (1660; the line is legible in later editions) lists “Stewed oysters in Scollop shells”, and in Jane Austen’s Emma (1815) Emma presses “the minced chicken and scalloped oysters” on her supper guests while her father frets that suppers are unwholesome. The popular theories that the word comes from the French escalope, a thin slice, or from the old English collop have no support in either dictionary.

The first scalloped potatoes were not sliced at all. The earliest we found is Charlotte Mason’s The Lady’s Assistant (London, 1773): “Potatoes scalloped”, mealy potatoes beaten fine with cream, an egg yolk and butter, filled into “scollop shells”, smoothed with the back of a spoon and browned in a Dutch oven as “a pretty supper dish”. E. Taylor’s The Lady’s, Housewife’s, and Cookmaid’s Assistant (second edition, London, 1778) gives: “Scalloped POTATOES. Boil, skin, and bruise potatoes in a little thick cream, put in melted butter, salt, nutmeg, pepper, some bread crumbs; roast them before the fire in scallop-shells”. John Farley’s London Art of Cookery (first published 1783) does the same with mashed potato smoothed into “scollop-shells”, scored with a knife and browned. That mashed version crossed the Atlantic and lasted a century: Marion Harland’s Common Sense in the Household (1871) still fills “buttered scallop shells” with mashed potato.

In American cookbooks, raw slices baked in milk turn up in the 1880s. The earliest we found is Margery Daw in the Kitchen (Auburn, New York, 1881): thin raw slices layered with flour, pepper, salt and butter, then “Pour over all the milk the dish will hold. Bake two hours in a moderate oven.” The White House Cook Book (1887) calls its version “Kentucky Style”: raw slices, butter, “a bit of onion chopped fine, if liked”, a little flour and about a quart (950 ml) of hot milk. Fannie Farmer’s 1896 “Escalloped Potatoes” layers 1/4 inch (6 mm) slices with flour and butter and adds “hot milk until it may be seen through top layer”. None of them makes a white sauce first. The oven and the potato’s starch made the sauce, which is exactly the principle this recipe uses, only moved to the stove. And Farmer’s menus already pair it with ham: “Broiled Ham. Scalloped Potatoes. Brown Bread and Butter.” (Pages that cite Mrs. Lincoln’s Boston Cook Book of 1884 for scalloped potatoes are mistaken: its “scalloped” recipes are seafood, eggs and leftover turkey.)

The 20th century added shortcuts. Campbell’s launched Cream of Mushroom soup in 1934, and by 1956 the Ladies’ Home Journal was printing “Creamy Scalloped Potatoes” layered with a can of it. In spring 1960 General Mills test-marketed Betty Crocker Scalloped Potatoes and Au Gratin Potatoes; the trade magazine Canner/Packer noted that the boxes cooked in “30-35 minutes vs. 1-1 1/2 hrs.” for raw potatoes. Scalloped potatoes are often called a Thanksgiving or Easter tradition, but we found no dated source that establishes either; the ham pairing, at least, goes back to 1896.

The French side of the story has its own myth. Almost every account says gratin dauphinois was first recorded on 12 July 1788, at a dinner in Gap given by the Duc de Clermont-Tonnerre. The source is document CC 1128 in Grenoble’s municipal archives, which the archive featured as its document of the month in April 2026. It is a payment order of 26 May 1789 telling the town treasurer to pay the caterer Allier 114 livres for the meal that “la ville”, the town of Grenoble, gave on 12 July 1788 to the municipal officers of Gap, at the Grenoble town hall. The archivist’s own note on the menu is the punchline: it lists “le fameux gratin (sans la précision de « dauphinois » hélas)”, the famous gratin, without the word “dauphinois”, alas. It does not say what the gratin was made of, so we cannot even be sure it was potatoes.

Nor is the no-cheese rule as old as purists claim. Escoffier’s Guide culinaire (1907 edition) makes gratin dauphinois with 125 g of grated Gruyère per kilo of raw sliced potatoes, in a buttered earthenware dish rubbed with garlic, and a sonnet recipe by the Dauphinois gourmet Maurice Champavier, printed in the 1890s, calls for eggs. The famous ban, “Surtout n’ajoutez pas d’œufs ni de fromage” (above all, add neither eggs nor cheese), comes from René Fonvieille’s La cuisine dauphinoise à travers les siècles in 1983. The sister dishes split along the same lines: Escoffier’s gratin savoyard swaps the milk for stock, pommes boulangère bake potatoes with butter-softened onions and no milk or cream, traditionally under a roast, Sweden’s Janssons frestelse layers potatoes with spice-cured sprats and cream (first printed as a recipe in 1940), and a Czech cookbook of 1897 layers boiled sliced potatoes with hard-boiled egg, smoked meat and cream and calls them francouzské brambory, “French potatoes”.