I use instant coffee a lot. It is super easy and quick to make. It dissolves immediately and leaves no sediment. Just perfect for the hectic lifestyle when you are constantly rushing from one errant to another one. And, to be honest, in all this hectic you do not even have the time to appreciate a good cup of coffee. A good cup of coffee requires time, relaxed feeling and maybe a friend or two. A luxury we do not always have. Therefore instant coffee definitely plays an important role in the coffee universe.
So the question presents itself: can you make it at home? Well, exact copy is out of the reach for the average cook. Instant coffee is freeze dried (lyophilized). This is a fairly complicated process which requires very low temperatures and vacuum. Definitely not something that you can easily achieve in your kitchen.
If we cannot reproduce exac instant coffee, can we at least make something similar?
Theoretical considerations
Just cooking a coffee and removing the water could be a solution. But it is not as simple as that. Removing the water by heating would remove all other volatile substances and with that also a great part of the taste. Waiting for water to evaporate would take too long. And in the end we would end up with a small amount of dry material, which would take forever to dissolve again. One important property of instant coffee is that it immediately dissolves and we definitely need something similar for our coffee. Therefore we can use the same approach as instant baby tea: add some sugar. This will increase the total amount of powder for easier handling and speed up the dissolution. And we will cook a strong coffee to reduce the amount of water that needs to be removed. Still, there is no easy way to remove the water quickly. But with concentrated coffee and added sugar, things should be manageable.
The trial
For the first trial I used 1 part coffee and 2 parts water (by volume) or, more accurately, 220 g of water and 45g of coffee. Water was brought to boiling point, removed from the stove and ground coffee was added and mixed. After 60 minutes the coffee residue was removed with the help of filter paper. Around 105g of filtered coffee was the end product. To this coffee I added 4 teaspoons (30 g) of sugar – about the amount I would use to sweeten my regular coffee. The end result was a sweet tasting coffee syrup, similar to the one from pocket coffee. I poured the syrup in a thin layer on a plate, to dry out quickly. After two days the syrup dried out a bit, but it was far from dry. It had a thick consistency and I scraped it around to speed up drying and make it easier to pick up. After additional two days sugar crystals started to form. After a total of seven days the powder was relatively dry. It was stuck to the plate and therefore hard to scrape off. Probably if I would mix it more frequently there would be less sticking to the plate. Nevertheless, I managed to scrape most of it off the plate. Since it was still sticky in places I let it dry some more. After another week it was hard so I tried to grind it with pestle and mortar. It turned out that there were still some sticky parts deep in the bigger lumps. After some additional drying and grinding, I got some powdered material. To get only the smallest particles, I used the sieve for the separation. The end product was fine powder with a pleasant coffee smell.
The testing
To my surprise it dissolved immediately in hot water, much faster than commercial instant coffee. The room filled with the smell of fresh coffee and the taste was heavenly. As a bonus, there was absolutely no residue at the bottom of the coffee cup. The same was true for the cold water – perfect and fast dissolution. I would surely rate such an instant coffee as a top class product. The only average thing was the taste. The taste was somewhat flat, missing the rich coffee tones. Probably more volatile compounds evaporated together with water. Nevertheless, a great success after all the troubles. To sum up, it is absolutely possible to make a great instant coffee in your kitchen, but it takes a lot of time and energy.
Related posts:
Cold brew coffee
Caffeine solubility, content in coffee beans and extraction
Lavender syrup
Caffeine from coffee, tea, matcha, mate, guarana and soft drinks – is there any difference?
How should I brew my coffee?
Caffeine extraction
Chocolate coffee beans
Wartime beer or How to make beer during wartime or zombie apocalypse