Here's what really makes mock apple pie taste like apples

After spending nearly a century sitting in the back of our grandmother's or great-grandmother's recipe boxes, depression-era pastry recipes are making a comeback. We're talking about wacky cake, peanut butter bread, and now mock apple pie. The list of ingredients contains no apples, but is filled with broken Ritz cracker bits instead.

Bakers who have made mock apple pie swear by the all-carb, mock-fruit pastry, with a broken cracker filling (made with no less than 36 crackers) that is infused with a syrup of lemon juice, lemon zest, cinnamon, and cream of tartar, then laid out in a pie crust. (The syrup is made separately before it is poured over the crackers).

Carina Finn, of Insider, made Ritz's recipe for the pie, and added ginger and vanilla extract to the syrup. She topped the pastry with a crumb topping made with cracker crumbs, brown sugar, and melted butter. The result: a pie that looked and behaved like a real apple pie. But how? 

Cream of tartar makes the pie taste like it has fruit

The real chemistry — or alchemy —happens because of the cream of tartar, which is also known as potassium bitartrate. We already use cream of tartar to stabilize egg whites used in making meringue. In analyzing the culinary magic that is mock apple pie, Gizmodo says it is the cream of tartar, which tastes tart and fruity itself, which tricks our tongues and minds into thinking that we're enjoying apples. Yesterdish further explains that cream of tartar breaks down sucrose into fructose and glucose, so when it cools, the pastry has the texture of pecan pie and the look, and taste, of apple pie.

The recipe is a legit American classic. Plenty of bakers have created their own spins on the recipe, including Serious Eats, which suggests topping the mock apple pie with whipped cream to balance out the serious sweetness of this mind-bending, super-efficient dessert.