Fruit concentrate is just fruit juice- but stronger. The idea is to take all of the flavor of the fruit and remove all of the water from it. The most common use I've seen is to freeze and store fruit juice compactly, but it can also be used for other things. For example, I made this fruit concentrate so that I could add stronger flavor to fruit juice gummy candies (I'll post an Instructable on that shortly!).
There are two ways to make juice concentrate from fruit. They depend on the type of fruit you are using.
For wetter, easily juice-able fruits, go to Step 1: Frozen Concentrate. Good for oranges, lemons, many other fruits if you have a juicer.
For fruits that will be a pain to juice, go to Step 2: Boiled Concentrate. Good for berries, pomegranate, apples, pears, etc.
Step 1: Frozen Concentrate
Use this technique for fruits that are easy to juice, such as oranges, lemons, limes, etc.
The method of freezing is based on the fact that juice can be extracted from ice- if you've ever made a fruit juice popsicle and sucked on it too hard, you remember that you sucked all the flavor out and had a pure ice-sicle left on the stick! Here's how to use that.
- Juice your fruit by any method- a hand juicer, a lime squeezer, by hand, into a freezer-safe container.
- Freeze it. This might take a while.
- Set up a container that can hold all of the juice with a narrow funnel on top. Upend frozen juice on top of it.
- Let sit at room temperature while the juice drips out.
- When the ice is sufficiently clear/white, you're done! Throw out the ice and keep the concentrated juice.
- Repeat freezing/thawing as necessary.
I juiced about 17 oz. of orange juice, and by repeating the freezing/thawing method described above twice, condensed to about 10 oz. It's much stronger tasting and thicker in consistency. You can also see a darkening of the color (the photos are in order).
Step 2: Boiled Concentrate
This method is for fruits that are harder to juice, such as those pictured above. If you have a juicer, you may want to use that to get juice, then skip back to the Frozen Concentrate step, since boiling the fruit can change the flavor and you may lose some of the natural sweetness.
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.
Step 3: Concentrate!
Now you have fruit concentrate!
Fruit concentrate can be stored and frozen for future use, mixed with water to be drunk as normal juice, used as a flavoring agent in drinks- or anything else you think of!