Crumb crust for pies, cheesecakes and other desserts can be made from a variety of ingredients – graham crackers, chocolate cookie crumbs, gingersnaps, vanilla wafer crumbs, shortbread or oatmeal cookie crumbs, to name a few. One crust is no better than another; it is a matter of the application. With refrigerated or frozen desserts, or creamy fillings in particular, a crumb crust juxtaposes beautifully with their smooth quality, creating an interesting and textural contrast. Crumb crusts are also super-easy to make. Here are our best tips for handling crumb crusts:
- Not all Crumbs are Equal: Graham crackers are used to make the most common crumb crusts, but do not overlook chocolate cookies, crisp oatmeal cookies, shortbread cookies, vanilla wafers or gingersnaps as tasty alternatives. As each of these cookies has its own flavor, texture and fat profile, you will have to fine-tune the amount of butter and other ingredients to create the crust. The technique, however, is the same.
- How the Cookie Crumbles: Grinding your cookies in a food processor fitted with a metal blade is the way to go. You want as fine a texture as possible so that the crumbs, once combined with the melted butter, create a nice, smooth and tight crust. In the image above, the cookies are not finely ground enough. Keep going. A pulsing action helps. In the image below, they are perfect. If you want to go unplugged, you could try placing your cookies in a heavy zip-top bag (not quite sealed to allow air to escape). Begin by crushing with your hands to break them down. Then use a rolling pin to smash and roll those crumbs into submission. It will take a little while to get the crumbs fine and even.
- Prep Your Pans: Nonstick spray figures into your prep, but how you use it depends on the kind of pan you are baking with. For loose-bottomed tart pans and springform pans, coat the bottom and sides with nonstick spray. For pie plates, you have be a bit more precise. If you coat the entire plate, you might have issues with the crust sliding down the sides, but we find it beneficial to spritz the top edge. Upon serving, this allows you to insert your serving utensil more easily and gives you a better chance at getting a clean slice out of your pie plate.
- Creating the Crust: Most crumb crusts are pressed into pie plates, tart pans or springform pans and certain techniques remain the same. Prep your plate or pan with nonstick spray. Once the crumbs and melted butter (and sugar and any other ingredients called for) are well combined, dump them into the prepared pan and begin to press all over the bottom in an even layer. With pie plates and tart pans, you will also be going up the sides. Depending on the recipe, with springform pans, you might only cover the bottom or you might go up the pan’s sides ½ inch, halfway or all the way. Follow the individual instructions. Fingers work fine (as seen below) but it is easy to build up too much crust at the juncture of where the bottom and sides of the pan meet.
Using a flat-bottomed measuring cup can help you create a nice sharp angle at that juncture; this makes a nice even layer of crust on both the bottom and the sides. As you can see in the image below, you simply use the flat bottom of the cup to press both down on top of the crust and also press it out towards the side of the pan.
- To Bake or Not to Bake: Some crumbs are baked or par-baked (meaning partially baked) and some are not. In general, the oven will be preheated to 350°F and the crust will be baked for 8 to 15 minutes (or thereabouts). Baking a crumb crust creates a firmer, crisper crust, making it more resistant to very-moist fillings like custards. Baking also enhances the flavors of the crumbs, just as when you toast nuts; the flavor improves. Fillings that require a chill in the refrigerator are often scraped into a fully baked crust. Fillings that need to be set in the oven are poured into a par-baked crust (see Blind Bake). This gives the crust a head start before the filling is added, and it finishes baking along with the filling. Some recipes, often frozen desserts, will skip the baking. While you wont get any flavor enhancement from time in the oven, the melted butter will be enough to hold the crust together.
- How to Tell if a Crumb Crust is Done: Lighter-colored cookie crumbs will darken upon baking, giving you visual cues to when they are done, but some crusts – chocolate cookie in particular – are so dark to begin with that they do not change color. In this case, use the time cues in the recipe and use your nose! You should just begin to smell the aroma and the crust should feel slightly dry. If the recipe recommends cooling the crust before adding the filling, make sure to do so. It is the little specific techniques that make a difference.
Images: Peter Muka