There was a popular saying on the Homefront during World War II: “use it up, wear it out, make it do, or do without.” Thankfully, most of us don’t live in such dire circumstances today as people did during wartime shortages. Some of us still have this frugal spirit, however, especially considering the added awareness of how disposable items take a toll on the planet.
You might find yourself noticing how much trash your household produces or asking “do I really have to throw that away?” For those of us who drink coffee daily (or hourly, in some cases), you’ve probably also asked, “can you use coffee grounds twice?” It seems wasteful to just dump that stuff in the trash, right?
Well, we’ll give you a qualified “yes” on that one, but there are some big exceptions for caffeine content and flavor. Read on to get the skinny on reusing coffee grounds, and some ingenious ways to repurpose your used up beans.
Can You Reuse Coffee Grounds?
If you’re hyper-particular about your brew ratio, flavor profile, and brew method, the answer to the question can you use coffee grounds twice is probably a no for you. It’s important to remember that grounds used a second time will never produce a brew comparable to the first time.
If you dilute your coffee with milk, sugar, or creamer, or are trying to cut down on your caffeine consumption anyway, then you can probably get away with using the grounds twice.
Coffee brewing experts talk about something called “extraction yield,” which is basically how much of the solid stuff from the coffee bean makes it into your brewed cup. This is where all of your flavor comes from.
A perfectly brewed cup of coffee hits the ideal extraction yield to pull out all the desirable flavors, like vanilla notes for example, and leave the undesirable ones, like bitterness.
If you use the same grounds twice, the solid material from inside the coffee has already been pulled out, so you will get a much flatter-tasting cup of coffee. Now, if your coffee simply serves as a vehicle for vanilla-flavored creamer, this might not be too much of a problem, and you could reuse the grounds if you want!
If you are particular about the flavor profile, however, you probably don’t want to experiment with reusing coffee grounds.
It’s 1 o’clock in the afternoon, and you need a little post-lunch jolt to keep you going. The grounds from your morning coffee are still in the coffee maker, so you just pour some more water in and run it again. But the resulting coffee doesn’t give you much of a jolt at all. Why is that?
Remember how we just talked about extraction? Yeah, the caffeine inside of your coffee grounds gets almost entirely extracted the first time it’s brewed. You won’t be able to get a second caffeine jolt by reusing coffee grounds in this way because there just isn’t any caffeine left in the grounds to extract.
You’ll basically be left with a coffee-flavored warm drink, which might not be all that bad if you’re looking for a warm beverage that doesn’t have too much caffeine. Some of us are used to the comforting feel of a warm mug of coffee to sip as we go about our day. Brewing your grounds twice could be a way to gradually wean yourself off of that afternoon caffeine, if that’s a goal of yours.
How To Reuse Coffee Grounds
If you still want to try and reuse your coffee grounds, here are some tips to help save the flavor.
Use Coarse Grounds
Generally, finely ground coffee extracts much faster and gets more of the water-soluble compounds out of the grounds and into the brew. Using a coarser grind might help the grounds have a little more flavor and caffeine left for the second time around.
First of all…..yuck. Definitely make sure you don’t try to reuse your coffee grounds after they have been sitting there, soggy and gross, for a couple of days. Coffee is very acidic and therefore discourages the growth of mold, but warmth plus moisture equals mold 100% of the time.
So, if you wait too long there will definitely be some kind of unwanted growth on your grounds, and this could make you sick.
Dry Them Out
If you really want to commit to maximizing your ground coffee, you can spread out the used grounds on a baking sheet and pop them in the oven on low heat until they are dried out.
It can’t put back the flavors that have already been extracted, but it can help it keep just a bit longer and improve the flavor somewhat.
Add Spice- Literally!
Have you ever tried coffee with a bit of cumin, cinnamon, or allspice sprinkled in the grounds? One way to revive grounds for a second use is by mixing in some spices for a little extra kick.
Some studies have even suggested that certain spices, including cinnamon, might contribute to your overall health and immune function.
What Type of Coffee is Best for Reusing?
Like we mentioned above, a coarse ground coffee is probably going to be your best bet for reuse, since there might be a little more extractable flavor and caffeine the second time around compared to finely ground coffee.
Reusing espresso grounds is not recommended because the high heat and pressure, along with the super-fine grind of the coffee beans, means almost all the flavor gets extracted with the first brew. It does not yield anything that tastes remotely like espresso if you brew it a second time.
If you absolutely must brew your coffee twice, you might want to try a medium roast or a dark roast coffee to get a little bit more flavor the second time.
7 Additional Ways To Reuse Coffee Grounds
Even though reusing coffee grounds twice to brew coffee is not recommended, there are tons of eco-friendly ways to recycle coffee grounds. Most of them can even replace commercial products that you buy for your home or personal care, meaning you’re further reducing your household use of plastic and chemicals. Win-win!
Fertilize Your Garden
One of the most popular uses for spent coffee grounds is making coffee ground compost. This isn’t nearly as difficult as you may think.
Most soils need extra nutrients added to them to grow optimal plants. Coffee grounds in soil can increase the nitrogen content along with other beneficial compounds in your soil, which encourages plant growth.
You need to balance the coffee grounds with plenty of dry brown material (like leaves or straw) so you don’t overdo it and get compost that’s too rich, but coffee grounds are a perennial favorite for composters – see what we did there?
Ditch the unpronounceable chemicals in your store-bought skin products and try coffee grounds instead! Coffee is a hot new additive to all kinds of skincare products, but you can easily mix some of these yourself at home.
NOTE: A lot of coffee skincare recommends using either fresh grounds or strong, brewed coffee because the caffeine content is one of the active ingredients that helps your skin. Since used coffee grounds don’t have caffeine in them anymore, they might be a little less effective but will still have some of their vitamin properties and exfoliation ability.
De-Puff Your Eyes
Maybe your coffee consumption has spiked due to some late nights – coffee can also help you minimize some of the cosmetic effects of staying up too late.
Some people swear by soaking some cotton balls in coffee and pressing them under your eyes for about 15 minutes. Others mix the grounds with honey, egg white, or Aloe Vera (which all have their own skin-brightening properties) and smear the homemade mask under the eyes to reduce redness.
Of course, make sure you don’t put coffee grounds IN your eyes! That would not make anything better and might earn you a trip to the E.R.
It’s a good habit to wash your face daily, but most standard face washes or soaps don’t deal with the build up of dead skin cells, pollutants, and makeup that hide out in your pores and cause breakouts.
Coffee works as an excellent exfoliant. The rough texture sloughs away all the buildup, leaving smooth, fresh skin underneath. It is recommended to use an exfoliant only once or twice a week – more than that may irritate your skin.
One of the lesser-known uses for used coffee grounds is as a body oil. Start with a safe, all-natural, nontoxic oil – our favorite is food-grade coconut oil. This can solidify if the temperature gets too cold, but it will melt when it touches your skin, so there’s no need to worry about it going bad if you see it start to turn solid.
Some people like the infusion method, where you simply mix coffee grounds and oil together and let it sit in a warm spot, like on top of your fridge, for several weeks.
A faster way is to melt the coffee and oil together in a pot (okay), slow cooker (better) or double boiler (best) to blend the two ingredients.
Coconut oil is crazy good for your skin and the coffee provides the exfoliation properties we talked about above.
Wood Furniture Polish
If you’ve ever wondered what to do with coffee grounds, it has probably never occurred to you that they might help restore and preserve your furniture. Back before artificial dyes were invented, people stained wood and dyed their clothes with natural ingredients, including coffee. You can still use coffee as a simple wood stain. It will yield a light brown color, depending on how much you use.
Some people even claim that rubbing a little bit of coffee grounds onto a piece of scratched furniture will help hide the scratch. As with anything involving a permanent color, we highly recommend you try this out on an inconspicuous area first, or a piece of furniture you don’t care about too much. You may not want your test run to be on great-grandma’s heirloom cabinet.
Can you reuse coffee grounds to help your garden in ways other than compost? Absolutely! You may have heard the trick of using beer to keep slugs away from your plants – coffee works the same way and you don’t have to waste your beer!
Spreading your used coffee grounds around your plants might help deter pests. Surprisingly, you can also smolder used coffee grounds as an all-natural mosquito deterrent. Just make sure you do this very carefully, so you don’t end up with a coffee scented inferno on your patio.
So, when all it’s all said and done, can you use coffee grounds twice? You can, but the second brew will be significantly less flavorful than the first time around and probably lack any significant caffeine.
Even though brewing your coffee grounds more than once might not be the best use of your precious coffee beans, they have surprising benefits ranging from your skin to keeping the mosquitos away from your next backyard party. Trying out one of our suggested uses for coffee grounds is a great way to take care of the planet while stretching your dollars.