Having tried instant coffee with finely ground roasted coffee beans prompted me to experiment with my very own.
For the testing, all I have was this old stock grounds. Label may not be elegant but its taste was superb. Yes, especially when freshly roasted. I left it inside refrigerator for quite a while. Its flavor must be severely deteriorated by now. My goal was making instant coffee so flavor is just a second thing. I can get another bag easily in case I succeed.
I recalled, I can make finely ground sugar from sugar crystal with our regular low cost blender. Perhaps it will work with roasted coffee too. I dumped it all inside. Then cycled between cranking the motor and manually mixing it with a spoon. Coffee tend to accumulate to sides preventing homogeneity. Extra manual intervention was needed. Then after half an hour, the grounds was finer than before but not enough for my purpose. Few more minutes and I decided to scrape the glass sides. Sticking powder seemed to have smaller particles than the rest.
I decided getting only one teaspoon. Placed it in mug and poured with freshly boiled water. Grounds floating on top was ugly evident. It quickly dissipated after few stir. However, the attempt to make instant coffee powder without visible specks failed horribly. Particles were sticking on cup sides and clearly seen when spoon was lifted. My tongue will surely feel it down to throat.
Next time, I may try measuring the volume of settled sediments. This way I can estimate the amount of fine grounds effectively suspended. On the other hand, I felt no particulates when I drank it. Smooth all the way down. The reason. I leave it 30 minutes before drinking.
Because I have no tools to make finely ground powder, my attempt to make instant from roasted coffee beans failed. My cocoa melanger can do it provided with enough time. Let us assume two days continuous running period. Almost the same length it is taking to make our chocolate products silky smooth. However, I cannot risk experimenting coffee with it. The stone is likely to absorb the strong coffee taste which will result mixture of coffee and chocolate flavor later on. It is not necessarily undesirable. It is not what I wanted with our earning product.
If the blender I used can be left for hours and can reliably spin the powder around in homogenous fashion. I will let it run for hours to achieved a nice result. Not, sadly. I can set up a ball mill later.
I can still test if what I did worked to some extent. That is by preparing it filter drip style. Fine powder will pass through the filter with ease while those with larger particles will be left behind.
There was a significant reduction in grounds quantity after the brewing process. See image. I originally planned on getting the weight of grounds before and after brewing, but the water retained in ground coffee got in my way. There was an additional drying work. Let us see if I can re-dry it successfully and weigh later. For the time being, the image served as good estimate.
The resulting brewed coffee was still grainy. Maybe I should use lesser grounds to water ratio the next time or instead use a good coffee filter paper. On the other hand, cocoa powder, can be prepared to a nice drink with a smooth mouthfeel. Unlike commercial instant coffee and juice, which are derived from liquid extraction and crystallization. Cocoa powder is a by-product of cocoa butter extraction process. It is a solid mass ground to a very small particle size. If it is possible with cocoa, then it must be doable with coffee.
I was successful in drying the grounds. The wait before brewing was 18 grams. The weight after brewing and drying was 15 grams. Three grams pass through the filter and successfully carried down to receptacle. That was 16 percent dissolved grounds.
Marvin is the lead chocolate maker of Ben and Lyn Chocolate Inc. Has strong background in food research and development. Occasionally conducts training and lectures. Lecturer of Cocoa Foundation of the Philippines. Do coaching and consultancy services on his free time.