After you’ve brewed a good cup of coffee, you might just toss the leftover ground coffee in the trash, although you may have wondered if there’s a way to reuse the same coffee to brew another cup.
Depending on your quality requirements or your personal taste, the answer to this question may vary.
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What happens to coffee during brewing?
When hot water comes into contact with coffee, several chemical reactions occur, of which we can highlight two important ones. First, the coffee grows to twice its size, then carbon dioxide is released. This is easily observed (when using a filter) in the form of bubbles.
When using a paper filter, only solids that can be dissolved by hot water get into the cup. In all other cases, such as As with the French press, however, coffee components that do not dissolve in the water get into the cup. Because of this, if we leave the coffee cup for a while, these residues will sink to the bottom.
How much caffeine is released from coffee during brewing?
There are several factors that determine the caffeine content of coffee. For example, Arabica coffee beans contain more caffeine than Robusta coffee beans.
Studies have attempted to standardize the caffeine content of coffee beans once they have been used. There is between 3.59 and 8.06 mg of caffeine per gram of coffee. That’s about half as much as in fresh coffee beans.
What does a cup made from recycled coffee taste like?
Ideally, coffee beans should not be reused. Otherwise, you better prepare yourself for a tasteless and watery drink. The taste is comparable to that of a cup of tea.
Are there any risks in reusing coffee?
If coffee is reused in the near future, no risks are known. However, if used coffee is stored for a longer period of time, fungi can form and germs can multiply.
What is the shelf life of used coffee beans?
Used coffee beans can last up to two years if properly dried and stored. Storage recommendations are similar to those for fresh coffee beans.
They should be stored in a dry, dark place, at room temperature and in airtight containers to avoid moisture. They can be stored in airtight glass or plastic containers, or vacuum-sealed bags.
Particular attention should be paid to drying the used coffee beans before storage. If they are not dried properly, they can lead to bad odors, mold growth and growth.
Reuse of coffee after extraction
The recommendations or suggestions change depending on the extraction method you use.
French press coffee reuse
In this case, it is very important that you use the coffee again immediately. The longer you wait, the more bitter it becomes. It is recommended not to wait more than 15 minutes after the first preparation.
Reuse of coffee after espresso machine
In the particular case of espresso, it is not recommended to reuse the beans because the machine extracts the coffee from the beans effectively and quickly. For this reason, the espresso is so concentrated that there is not much left to extract after preparation.
The residues or spent coffee beans then give a very bitter extraction, very different from the first.
Reuse of coffee in Cold Brew
With cold brewing, better results can be obtained through reuse if the initial brewing time was short, i.e. between 6 and 8 hours, since the extraction of the coffee is directly related to the brewing time. In other words, while preparing a long brew, chances are there will be nothing left over for a second brew.
Another aspect is that used coffee can be mixed with fresh coffee to create a new blend. This can complement the brew and give it more strength and flavor.
Other ways to reuse coffee
Like the waste from coffee production, the coffee residue from brewing can be used in areas other than the actual brewing. Here are some examples of what to do with coffee after it’s been used or repurposed, other than throwing it straight in the trash.
Reuse of coffee as fertilizer
This is the easiest way to reuse coffee, you can use it in flower pots or in the garden, for example. Used coffee is high in nitrogen, phosphorus, and a few other micronutrients that leach into the soil and keep plants healthy.
In addition to its chemical compounds, reusing coffee this way also attracts earthworms, making it even better for gardens and outdoor plants. It is enough to distribute the coffee among the plants and water them normally.
Reuse of coffee in compost
Compost is also great for the garden if you don’t need it right away. This process helps the soil retain water and provide nutrients. However, the compost should not consist exclusively of coffee waste.
Reusing coffee as an odor eliminator
Coffee removes strong odors in a similar way to baking soda, it absorbs them. For example, it can be used in the fridge.
Before using, you should dry the coffee completely.
Reuse coffee to exfoliate your skin
Recycled coffee can be applied directly to the skin with a little water. It can even be mixed with a little coconut oil for a gentler exfoliation. It can also be used on the lips mixed with some honey.
Remember to apply a moisturizer after use.
Reuse coffee on the barbecue
Coffee goes well with smoked foods such as grilled meat. Coffee gives it an intense taste that also goes well with vegetables.
It is prepared as a rub and mixed with salt, pepper and paprika. The meat is covered with the sauce and then with a thick layer of the rub.
The total preparation time is about an hour, so you can store the coffee very well after brewing and have it ready for the next roast.