Used Coffee Grounds
- Caffeine level41 mg
- Caffeine strengthMODERATE
- Serving size1 half tbsp (7 g)
Used or spent coffee grounds still contain a significant amount of caffeine.
A study conducted by The Department of Nutrition, Food Science and Physiology, School of Pharmacy, University of Navarra found that spent coffee grounds contained 3.59 to 8.09 milligrams of caffeine per gram of used coffee grounds.
For the amount listed above, we took the average of this and multiplied it by the amount of ground coffee typically used to make an espresso.
Caffeine in Used Coffee Grounds Varies by Brew
Brewing methods with longer brew times will result in less caffeine in the spent coffee grounds since caffeine is highly water soluble.
Take Care With Disposing
Care should be used when disposing of spent coffee grounds as caffeine has been detected by some municipalities in our waterways and reservoirs.
Want to add them directly onto your garden? Don't. Despite anecdotal advice - research shows that direct application of coffee grounds will inhibit growth of plants. So at the least, try to compost them first.
Ingredients in Used Coffee GroundsUsed Ground Arabica Coffee
How Does It Compare With Other Foods?
Caffeine (mg) per Item
Sourceshttp://pubs.acs.org/doi/abs/10.1021/jf3040594 Bravo, J., Juaniz, I., Monente, C., Caemmerer, B., Kroh, L. W., De Peña, M. P., & Cid, C. (2012). Evaluation of spent coffee obtained from the most common coffeemakers as a source of hydrophilic bioactive compounds. Journal of agricultural and food chemistry, 60(51), 12565-12573. Hardgrove, S. J., & Livesley, S. J. (2016). Applying spent coffee grounds directly to urban agriculture soils greatly reduces plant growth. Urban forestry & urban greening, 18, 1-8.
Other references. Last updated on 4 Mar 2021.
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