Ground coffee and coffee beans can be expensive, and it seems a shame that most people throw them out after only one use. But, can you reuse coffee grounds for a second cup of coffee or anything else, for that matter?
You can reuse coffee grounds for another brew. Still, because the coffee grounds have already undergone an extraction process, the second brew will be weaker and contain less flavor and caffeine than the first one.
This article will discuss what brewed coffee from reused grounds tastes like, how many times you can reuse coffee grounds, whether or not you can use them in a Keurig or French press, and other handy uses for used coffee grounds.
Can You Use the Same Coffee Grounds Twice?
If you were wondering whether or not you can reuse coffee grounds to make more coffee, or if you can reuse coffee grounds for a second cup, yes, you can use them twice!
To understand the characteristics of used coffee grounds, it’s a good idea to learn how coffee is brewed using coffee grounds the first time around, what affects the taste, and what happens when you brew it twice:
The Coffee Brewing Process Using Fresh Coffee Grounds
When coffee is brewed, many of the solids are dissolved in the water and bind to it.
These soluble components are what give coffee its rich, aromatic, and flavorful taste.
Suppose you use filter paper in your brewing method. In that case, the undissolved particles will remain on the paper. In contrast, other methods (such as the French press method) leave the undissolved particles in your cup.
Factors That Affect the Taste of Brewed Coffee
To brew the perfect tasting cup of coffee, you need to get the following elements right:
- Optimal water temperature
- Best water and coffee ground ratio
- Size of coffee grounds
- Water contact time
- Exposure to heat
Optimal Water Temperature
According to the National Coffee Association, the optimal temperature for brewing coffee is between 195 and 205 degrees Fahrenheit (or 91 and 96 degrees Celsius).
Coffee is more soluble in water when it is close to boiling. Therefore, most auto-drip coffee machines heat the water to these temperatures.
Water that can effectively dissolve the flavors of the ground coffee results in a full-bodied and robust taste.
Best Water and Coffee Ground Ratio
If you’ve succeeded in finding the best balance between coffee grounds and water, you’ll likely agree that it tastes best when the brewing process can extract 20% of the goodness from the grounds.
In real life, this equates to around one or two level tablespoons of coffee for every six ounces of water, depending on how strong you like your coffee.
Size of Coffee Grounds
More coarse coffee grounds have less surface area that comes into direct contact with the water, resulting in less time for the flavors to be extracted by the brewing process.
This is ideal if you use a French press, which has a lengthier brewing process.
Finer grounds are more suitable for drip coffee machines as the brewing time is fast, at only four to six minutes.
Water Contact Time
The longer water comes into contact with coffee, the more time there is for it to draw out all the elements of the grounds.
Quick brewing methods may not give enough time for the coffee to develop a rich and aromatic smell and taste, and getting the balance right is essential.
As a general rule of thumb, between two and four minutes is the perfect brewing time for coffee.
Exposure To Heat
Have you ever noticed that coffee left warming on the machine or a warming plate tastes bitter and sometimes acidic?
This is because exposure to heat over a long period (i.e., a few hours) means that the bitterness of the coffee is drawn out and enhanced.
Brewing Coffee With Used Coffee Grounds
When using used coffee grounds to brew more coffee, over-extraction occurs as too many components are drawn out of the grounds.
Over-extraction results in coffee tasting bitter as the tannins (the slowest components to be extracted) are now higher.
When the coffee grounds were brewed the first time, most of the oils, sugar, and acids (which give the coffee its distinctive taste) were dissolved in the water, leaving very little behind.
The result is coffee that tastes weaker, duller, and less robust than the first brew.
Over-extracted coffee can also taste astringent, as the brewing process has had enough time to draw out the polyphenols, which have a bitter taste, bind to the proteins found in saliva, and cause your mouth to feel unpleasantly dry.
Can You Reuse Coffee Grounds To Make More Coffee?
It is safe and possible to reuse coffee grounds to make more coffee. However, reusing coffee grounds for another brew can result in over-extracted coffee that’s bitter, watery, and less flavorful.
What Does Coffee Brewed From Reused Grounds Taste Like?
Coffee made from used coffee grounds can taste weak, bitter, and astringent. This is because most of the coffee’s flavor has already been extracted from the grounds during the first brew.
- Weak: Since much of the flavor, body, and robustness were already extracted to make the first pot of coffee.
- Bitter: The longer the coffee grounds are exposed to water and extracted, the more bitter it tastes.
- Astringent: Because the polyphenols have been removed, bind the proteins in saliva, and cause a dry mouth effect.
Although much of the flavor from used coffee grounds have already been extracted, there are still certain things you can do to help your coffee taste as good as possible.
If you don’t take steps to preserve the flavor of your used coffee grounds, your next brew can taste weak, bitter, and without much flavor.
To make the most out of used coffee grounds, it’s recommended that you allow them to cool down fully in a covered container so that the flavor is retained.
If you immediately reuse coffee grounds that are still warm, your coffee can taste burned and bitter.
Another option could be to use only dark roast coffee. With its naturally rich, robust, and strong taste profile, dark roasted coffee can help to keep the lovely coffee taste for longer.
Some people add a scoop of unused coffee grounds to their used ones to give the second batch more flavor, caffeine, and body.
As long as you follow the above suggestions, you’ll be making the most out of whatever flavor remains in your coffee grounds.
Do Reused Coffee Grounds Have Less Caffeine?
Reusing coffee grounds results in far less caffeine content in the second batch of coffee due to much of the flavors and other components (including caffeine) that have been pulled out during the first extraction process.
According to the American Chemical Society, regular coffee beans contain between 10 mg (0.01 g) and 12 mg (0.012 g) per gram (1000 mg).
Comparing this with coffee grounds which have been brewed twice, the caffeine content is only between 3.59 mg (0.00359 g) and 8.09 mg (0.00809 g) per gram (1000 mg).
This shows that a significant amount of caffeine is lost when reusing coffee grounds. So, if you drink coffee for the boost that caffeine gives you, it would be better not to reuse the grounds.
How Many Times Can You Use Coffee Grounds?
There is no limit to how many times you can reuse coffee grounds, but you won’t receive the same taste benefits from them after each subsequent brew. Reusing grounds will result in weaker, less flavorful coffee, and using them repeatedly will make the coffee unrecognizable in taste.
Considering that wet coffee grounds are the perfect breeding ground for mold, fungus, and bacteria (i.e., they are damp and warm), if left to sit for a long time, you may want to reconsider using them more than twice to make coffee.
If you don’t want to waste them, you could always reuse them for another pot of coffee (if you don’t mind the reduction in richness and flavor) and then dry them out for use in the home, yard, or as a beauty treatment.
Can You Reuse Coffee Grounds To Make Cold Brew?
It is possible to reuse coffee grounds to make cold brews, but you probably won’t taste the same taste as fresh grounds. Reusing old coffee grounds to make cold brews can also result in a watery taste, especially after adding your milk, ice, and any other desired flavorings.
How Many Times Can You Reuse Coffee Grounds for Cold Brew?
You lose richness, caffeine, and flavor each time you reuse coffee grounds (even for cold brews). A second reuse for cold brews is possible, and you can compensate for lost flavor with some flavored syrup. Reusing them more than twice produces a cold brew that tastes like milk with a hint of coffee.
Can You Reuse Coffee Grounds for Espresso?
Let’s face it, most people who drink espresso do so because it provides an instant hit of caffeine and a small but powerful shot of strong coffee taste.
It is perfectly fine to reuse coffee grounds to make espresso. However, the robust coffee taste that is so characteristic of espresso will sadly be diluted.
Can You Reuse Coffee Grounds in a French Press?
The French press method of making coffee is simple and fuss-free.
You can reuse coffee grounds for another round with your French press, but bear in mind that the longer the grounds are exposed to water and heat, the more bitter they will taste.
Some folks pour their first round of coffee and then immediately remove the grounds from the French press; so that as much flavor as possible is retained and it doesn’t taste as bitter.
Can You Reuse Coffee Grounds in a Keurig?
One of the only drawbacks to owning a Keurig is the K-Cups’ cost. This is because K-Cups are placed in the Keurig machine to make the coffee.
If you have been thinking about reusing the coffee grounds in your K-Cups, this is entirely doable. However, as with reusing coffee grounds with other brewing methods, your Keurig will produce weaker coffee the second time around.
Because the pod’s cover will have been pierced the first time around, you’ll need to remove the cover and replace it. Reusable Keurig lids are widely available for sale, allowing you to reuse the grounds.
Suppose you don’t mind sacrificing some flavor. In that case, you’ll be saving yourself money and also doing your part for the environment by reusing the pods, too.
Other Uses of Used Coffee Grounds
If you aren’t keen on reusing your used coffee grounds to make more coffee, the good news is that you can reuse them in plenty of ways!
There are many popular uses for used coffee grounds:
- Making a homemade body scrub
- As a fertilizer for your plants or vegetables
- General household cleaning
- Improve your compost heap
- For use as a natural deodorizer
- As a detoxifying shampoo
- Natural flea treatment for pets
- For use as a delicious meat tenderizer
Making a Homemade Body Scrub
A good body scrub can effectively remove dry skin. You can make a body scrub yourself with used coffee grounds and other ingredients you already have.
Coffee grounds can be used on their own as a natural skin exfoliator, or they can be mixed with coconut oil, essential oils, or with your regular shower gel to make a great-smelling scrub.
As a Fertilizer for Your Plants or Vegetables
Are you an avid gardener? If so, your old coffee grounds can be used to make a highly nutritious fertilizer for plants and vegetables that is also very cost-effective.
Combine some coffee grounds with plant cuttings, grass, dry leaves, and brown flower petals, and you have an excellent fertilizer to place on your plants or vegetables.
General Household Cleaning
Used coffee grounds have a grainy and rough texture, making them a cheap scrubbing medium.
They are highly effective at gently removing stubborn grime on dirty pots, pans, and work surfaces.
Grab some used coffee grounds, and rub over the affected areas.
Coffee grounds can also have a sanitizing and antibacterial action, providing additional benefits.
Improve Your Compost Heap
Coffee grounds are naturally rich in nitrogen, making them excellent for compost heaps.
If you use biodegradable filter paper, include this with your used coffee grounds to give your compost heap a healthy boost.
For Use as a Natural Deodorizer
Are you struggling to get rid of unwanted odors in your home? It can be tricky getting stinky shoes, smelly pets’ bedding, and musty refrigerators smelling fresh again.
Luckily, used coffee grounds can fix these problems!
For smelly refrigerators or closets, fill a jar or container with some used coffee grounds, and leave uncovered for a few days. The coffee grounds will absorb the unwanted smell and neutralize any remaining odors.
If your shoes have a stubborn odor, try filling two small mesh bags with dried, used coffee grounds, leave for a few days, and your shoes should smell much better.
Pets’ bedding can often smell very unpleasant, and even washing it does not permanently remove the stink. However, this problem can easily be resolved by sprinkling used coffee grounds over the malodorous bedding and allowing it to rest for 24 hours.
Brush the coffee grounds off the bedding, rinse, and then wash with biodegradable laundry detergent. You will be amazed at the transformation!
After slicing onions or chopping garlic, your fingers can have a pungent smell. Use your saved coffee grounds to wash and exfoliate your hands, and they will smell fresh again.
As a Detoxifying Shampoo
It is easy for the build-up to occur on your hair and scalp after everyday use of hair gels, hairsprays, and leave-in products.
Unfortunately, detoxifying shampoos that remove build-up can be pretty expensive. Still, you can make your own with your used coffee grounds.
Before washing your hair, take a handful of used coffee grounds and gently work it over your hair and scalp. This will remove build-up and help detoxify your hair to make it shiny and lightweight again.
If your coffee grounds contain caffeine, this can help stimulate hair growth.
Natural Flea Treatment for Pets
If you are concerned about the toxins and chemicals present in flea removal products for pets, used coffee grounds are a natural option.
Not only is it inexpensive, but it is natural and quite effective.
After bathing your cat or dog, take a handful of used coffee grounds, and work it through the fur. Then, rinse your pet as you normally would, and enjoy a flea-free pet.
For Use as a Delicious Meat Tenderizer
Due to the acids and enzymes present in used coffee grounds, they make a fantastic meat tenderizer.
The enzymes effectively break down the fibers in the meat to make them more tender, and the acids in the grounds subtly add flavor.
To make your own meat tenderizer, all you need to do is allow some used coffee grounds to dry and store them in an airtight container.
When you’re ready to prepare your meat, rub some grounds over the meat and allow them to infuse for a few hours. They work similarly to a meat rub and can be used in combination with other meat spices and marinades.
If you want to enjoy a cup of coffee that is full-bodied, rich, robust, and has plenty of flavor and aromas, reusing your coffee grounds is not a good idea.
However, if you cover the coffee grounds while they are cooling down, you can avoid a lot of the bitter aftertaste.
As long as you don’t mind your coffee tasting slightly bitter, weaker, and lighter, there is no reason not to reuse your coffee grounds.
Alternatively, you can use old coffee grounds in many different areas, so you don’t have to feel like they will go to waste.