12 Ideas for Using Up Leftover Coffee

When you've brewed more coffee than you can drink in a morning, it's a shame to let that java go to waste by pouring it down the drain. Instead, you can put it to use with these clever tips for using up leftover coffee.

Before you get started repurposing that extra joe, however, there are a few things you should know. First, coffee becomes increasingly acidic as it sits out and oxidizes, says Tomas Peters, cafe manager with the Good Ambler bakery and coffee shop in Chicago (the cafe has a planned opening for this spring). To keep it as fresh as possible, transfer your leftover coffee to a heat-proof, airtight container after it comes to room temperature, then store it in the fridge and use within a day or two. (We like using mason jars, $11 at Bed, Bath & Beyond.) You can also freeze coffee in ice cube trays—use the cubes in iced coffee, or pour warm milk over them to make kori-kohi coffee.

Also, if you know you're not going to drink the entire pot of brewed coffee, turn off the hot plate as soon as you're finished. Leaving coffee hot for hours burns off all the aromatic flavors and turns it merely into a caffeine vessel, explains Dorian Bodnariuc, a former barista and coffee writer. "The bitter flavors will survive [extended heat], but all the delicate tones will be gone," he adds.

Ready to transform leftover coffee into something delicious? Here's where to start.

Make whipped coffee.

Instead of using instant coffee to make this trendy beverage, you can cook down brewed coffee with a little sugar, then whip for a few minutes until it's nicely frothed, says Kristine-Ellis Petrik, operations manager with Java Love Coffee Roasting Co. Serve with non-dairy milk over ice for an afternoon treat, or add cocoa powder to make a Whipped Coffee Mochaccino.

Flavor frosting.

If you're making a basic frosting recipe, sub in a few tablespoons of brewed coffee for whatever liquid your recipe calls for, and you'll have a tasty coffee-flavored cake or cupcake topper, says Alice Williams, healthy living blogger with Honestly Fitness. This would pair especially well with chocolate cake.

Freeze into ice cubes.

These are handy for tossing into iced coffee (without watering it down) or adding to smoothies. You can also freeze a combination of milk or cream and coffee into cubes for a little variation, says Bodnariuc.

Blend up a smoothie.

Toss a few coffee ice cubes into your blender with your favorite protein powder (vanilla or chocolate work great) and some non-dairy milk, says Williams, or use chilled leftover coffee as the liquid in a smoothie made with frozen bananas, protein powder and ice cubes.

Bake with it.

Substitute leftover coffee for the water in recipes for your favorite desserts, such as cakes or brownies, says Peters. This works especially well for boxed mixes and gives the final product a rich flavor.

Toss a salad.

You can use the acidity of leftover coffee to your advantage by making a salad dressing, which is a combination of oil and acid. Try taking your favorite vinaigrette recipe and decreasing the amount of vinegar in lieu of coffee, says Peters, who recommends a coffee-balsamic vinaigrette over a spinach salad with creamy goat cheese, pears and walnuts.

Whip it into a sauce.

There are several sauces that can be amplified with leftover coffee, which lends them the term "red eye." For example, add coffee to hollandaise sauce to kick Eggs Benedict up a notch, by whisking together egg yolks and coffee before drizzling in butter; or use black coffee in meat drippings to make red-eye gravy.

Play bartender.

Don't have any coffee liqueur to shake up a martini or a White Russian? You can easily make your own, says Jake Barnett, co-founder of Old Fashioned Beverage & Hospitality in Kansas City, by making a rich simple syrup from coffee and brown sugar. Then, add your liquor—rum, bourbon or vodka will do—and spices like cinnamon and cloves, and let it infuse for a few days in a glass jar in the refrigerator. From there, you can add it to cocktails, sip it on the rocks or even drizzle over ice cream, Barnett says.

Make a mocktail.

Shake 4 ounces of chilled leftover coffee with a little simple syrup, lime juice and a splash of tonic, then serve over ice, recommends Jake Wagner, a barista at Intelligentsia Coffee.

Marinate meat.

You can tenderize an inexpensive cut with a coffee-based marinade, says Cynthia Hillson, author of How to Feed Your Family. Start by reducing one cup of brewed coffee by a third; let it cool, then add a few tablespoons of Worcestershire sauce, a little garlic, a sprig of fresh rosemary, cracked pepper and a few tablespoons of oil. You can also add a little brewed coffee to chili (about ¼ cup for each pound of meat) or to a pot roast before braising, along with beef stock.

Add it to pancake or waffle batter.

Get a double dose of coffee with your morning meal by adding a couple tablespoons per cup of your batter, depending on how much you like a coffee taste, says Williams.

Pour it over your garden.

You've likely heard coffee grounds can help fertilize gardens, and leftover coffee can serve the same purpose. Simply dilute your coffee with extra water first (try a ratio of ¼ coffee to ¾ water), then pour what's left from your pot (or even your mug, as long as it's black coffee) over your potted plants. The liquid caffeine is a source of nitrogen for plants, which promotes strong, healthy stems, says Emma Sothern, co-founder of Garden Zoo, a resource for beginner gardeners. Coffee also contains magnesium and calcium, which act as nutrients for plants. You can add diluted coffee to your plants once or twice or week to see positive results, Sothern says.