If you make your morning coffee at home, you might just throw those spent coffee grounds away once the brew is finished. But can you reuse coffee grounds for cold brew? Or will you lose some of that rich cold brew taste?
Depending on your coffee intake, you may be throwing away up to several scoops of used coffee grounds each day.
You may have wondered whether you could reuse grounds from brewed coffee to make a batch of cold brew. Or whether you could make a second batch of cold brew from the same grounds you used to make the first one.
While technically either is possible, reusing coffee grounds to make cold brew is not a good idea, for several reasons. Read on to see what those are.
Note: If still want to make cold brew from used grounds, you’ll find some of the most effective ways to do so later on in the post.
Why you should avoid reusing coffee grounds to make cold brew
There are 4 main reasons why it’s not a good idea to reuse grounds for cold brew:
- Caffeine level
- Brewing time
Cold brew gets its intense, smooth flavor and extra caffeine by steeping freshly ground coffee beans in cold water for a long time, usually around 12 hours. So it makes sense that reusing grounds could change all of these characteristics. But let’s take a closer look at how each one may be affected.
The cold brewing method doesn’t use heat to extract flavor from the ground coffee. Instead, it uses time. This is more gentle on the ground beans than the high heat used in a regular coffee maker. But you can still over-extract the grounds if you reuse them for cold brew.
Trying to extract them a second time can result in drinkable cold brew, but you may notice more astringency or bitterness to the coffee taste.
And since you get the strongest, freshest flavors from the first extraction process, a second batch of cold brew using the same grounds will turn out to be weaker and blander.
In short, you will not get the same tastiness or intensity from reused coffee grounds as you would with fresh ones used during the first brew.
A smooth, silky texture is another hallmark of well-brewed, fresh cold brew. Resuing old grounds will alter that texture. The result will be a grainier, less smooth coffee that simply doesn’t have the same creamy mouthfeel.
Adding creamer could help blunt this, and cover up any added bitterness, but it will not give you the same smooth texture as cold brewing coffee with fresh grounds.
The cold brewing process extracts a lot of caffeine from fresh coffee grounds. That’s why it can give you an extra jolt of energy over just regular coffee.
But once those grounds are spent, you won’t get the same caffeine boost from resuing them for a second batch. It will simply won’t contain as much caffeine.
So if your primary reason for making cold brew is a strong coffee with an extra dose of caffeine, you may want to reconsider using old coffee grounds.
Longer brewing time
Making a batch of cold brew with fresh grounds already requires hours of steeping. But to extract flavor from used grounds, you’ll need to let the grounds soak in water for an even longer brew time.
Think 12-24 hours for the second batch. You could do it for less, but then you’re risking making the cold brew even weaker.
Reasons to reuse coffee grounds
Ok, so we’ve gone over some reasons why reusing coffee grounds for cold brew may not be the best idea. But there are some good arguments for why you may want to use coffee grounds again.
Coffee can be expensive. And throwing away all those grounds can be wasteful. Reusing them to make cold brew can save you some money and limit your environmental impact.
You can also use spent grounds for things other than batches of cold brew.
Old coffee grounds can make a great garden fertilizer, as they’re rich in nutrients like nitrogen, calcium, iron, and, potassium that help nurture plants.
They can also act as an effective deodorizer in garbage cans, as the grounds will absorb strong odors in the trash.
2 ways to reuse coffee grounds for cold brew
I get it. You’re the dogged type. You don’t see reusing spent grounds to make cold brew as a bad idea. You view it as a challenge.
Well, you’re in luck. Here are 2 ways to reuse coffee grounds and still get the best results with a second brew.
Method 1: Resuing grounds from brewed coffee
If you use a regular coffee pot, this may be for you.
- First, brew a pot of hot coffee as you normally would.
- Once it’s done, remove the used grounds from the coffee filter and place them in an airtight container in the fridge and let them cool. (If you don’t plan on making cold brew for a few days, leave the grounds in the fridge until you’re ready to use them so they stay as fresh as possible.)
- When you’re ready to make the next batch of cold brew, take the used grounds from the fridge, place them in a glass jar or mason jar.
- Mix in water. The usual ratio for cold brew is 4:1, so if you have half a cup of used grounds, you would add 2 cups of water. Adjust the amount of water to your tastes.
- Cover and let it steep in the fridge for 18-24 hours.
- Strain the coffee into another jar with a mesh coffee strainer of cheesecloth.
- Enjoy! Store any remaining cold brew in your fridge.
Method 2: Resuing grounds from cold-brewed coffee
This is very similar to method 1, but you’re resuing grounds from a previous batch of cold brew rather than from a brewed pot of coffee.
- Take the coffee grounds strained from the first batch of cold brew and place them in a mason jar. (If you are waiting a few days between batches, place the used grounds in an airtight container in the fridge).
- Pour cold water over the grounds using the same 4:1 ratio of grounds to water (or whatever tastes good to you).
- Stir the water and grounds together.
- Cover and steep for 18-24 hours and enjoy.
With either method, it’s a good idea to test the cold brew at around the 12 and 18-hour mark to see if it’s to your liking. Brewing for too long can over-extract the beans and result in a bitter taste.
Can you keep reusing coffee grounds to make cold brew?
It’s best to not use the same coffee grounds more than twice. At that point, most of the flavor, texture, and caffeine have been extracted from them. Repeatedly using the same grounds will simply give you weak, bitter coffee.
You could mask some of that will creamer or sugar, but eventually the coffee will simply not be palatable.
Yes, you should refrigerate cold brew coffee in a sealed container once it’s done steeping. This will prolong its shelf life and preserve its flavor.
You shouldn’t stir cold brew while it’s steeping as that could sink the coffee grounds and make the cold brew weaker.
The bottom line
So, can you reuse cold brew coffee grounds? Yes. Should you? That’s up to you. If you’re in a pinch and you’ve run out of fresh grounds, you could reuse them to make another cold brew batch.
However, the best way is to stick with unused ones. Coffee lovers know that a good cup of coffee, whether it’s cold brew or not, is one of life’s great pleasures. So it only makes sense that using fresh ingredients will give you the best-tasting result.
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