Essentially, the idea is to get the juice out of the fruit by boiling the fruit to a pulp. The heat denatures the proteins, releasing some of the sugars (and flavor) into the water. The water then boils off as steam.
- Wash, peel, and slice fruit as necessary. I only washed the blueberries; picked the seeds out of the pomegranate, washed and sliced the strawberries.
- Put the fruit in a pot; add water to just cover. This is so that you don't accidentally fry your fruit.
- On medium heat, bring to a boil (uncovered).
- Boil at least until the fruit is mushy pulp. Boiling longer will reduce water content, but may alter the flavor of your concentrate.
- Strain pulpy fruit sludge. I used a sieve and then a cheesecloth.
The pack of blueberries shown yielded about one cup of concentrate. Four manilla mangoes made a comparable amount. The pomegranate made 1/4 cup at best. The strawberries came out to around two cups.