You hit snooze one too many times this morning and now you’re in a mad dash to get out the door. In your haste, you forget to make coffee. Can you just reuse the old coffee grinds from yesterday’s filter?
The answer, unfortunately, is “not really.” While we don’t believe it to be dangerous, you won’t get a good cup of coffee from the second (and subsequent) batch(es). There are a few factors to consider before making the decision to re-use your grounds.
The first thing to think about is the quality of the coffee beans. If they are low quality, there’s a chance that they’ve already been over-extracted during the brewing process. This means that all of the flavor has already been pulled out of the beans and recyling them will likely result in a weak cup of coffee. However, if you’re using high quality beans, recycling them won’t be as much of a problem.
This also depends on the grind size. If you used a smaller grind size, say for drip coffee, you’ll have a higher percentage extraction then a larger grind, like you’d use for a French press. The coarser grind will be better the second time the a smaller grind would be.
Another thing to consider is how long the grinds have been sitting out. If they’ve only been sitting for a few minutes, they should be fine to reuse. However, if they’ve been sitting for hours (or even days), the chances of bacteria growth increase exponentially. Therefore, it’s safer to err on the side of caution and make a fresh pot of coffee rather than risk drinking bacteria-laden coffee.
Reuse Or Not Worth It?
So, should you recycle coffee grinds? Ultimately, it’s up to you. If you’re in a hurry and desperate for caffeine, go ahead and give it a try. Just be sure to use high quality beans and recycle them within a few minutes of grinding them. Otherwise, it’s best to play it safe and start from scratch.