When I was young my father and I spoke about coffee and what he does to make the taste better. I asked him if there are different types of milk and he was confused. I then said "Maybe it's something made from milk." He replied Cheese and he purchased some kind of cheddar which we soaked in a cup of coffee in a bowl. He tried it in a day after leaving it in the fridge and said this tastes delicious.

I added that this is good but shouldn't be done with such a salty cheese and instructed him to drink water.

We continued speaking about things made of milk and I learned about yogurt. I asked him how long a food takes to digest compared to a fluid and learned that it's much slower.

Since then he stirred instant coffee powder in his sugary yogurt and ate it before work in the morning. It's sort of like a sustained release coffee because of the way the beans digest and similar to water yogurt is good for the kidneys which I had learned from him. In a way perhaps even better than just cold water. Within a few years other people in Bulgaria started doing this. He liked to speak to his friends and the thought spread.