I've been making fruit ice creams this summer, using a custard base recipe: start with basic creme anglaise, add cream, chill, add fruit puree and into the machine, a Cuisinart. The raspberry and blackberry versions are great; the nectarine was a problem, because to get enough fruit flavor I had to use a lot of puree, which raised the water content of the mix and led to too many (or too big) ice crystals. It tasted good, but the texture was less than ideal.
My first thought was to centrifuge the puree so as to concentrate the solids and allow some of the water to be poured off. But the only centrifuges I can find online are designed for laboratory use; they cost a ton, and they're set up to hold small test tubes, not a good-sized--say 500 ml. or so--container. Any suggestions?
What about using the pulp produced by a centrifugal juicer, such as a Breville? Mine cost $300, but they make a smaller one for half that.
Interesting idea--thanks. I'm concerned that, since the point of a juicer is to give you flavorful juice, it wouldn't do what I'm aiming at, which is to remove water while leaving a concentrated flavorful puree behind. But it might be worth a try--at worst I'd have a good juicer.
I've also been making a lot of fruit gelati this year. I chop fruit, add some of the sugar and let it macerate for a while - perhaps 30 - 60 minutes. This draws a lot of the liquid out of the fruit. Then I puree it before adding to the custard base.
If your fruit is too juicy, you can reduce the liquid on the stove, just gently cooking it down. This should also intensify the flavor.
It's a lot simpler than getting another piece of equipment.
Reduction sounds good. When you macerate the fruit, is the liquid that's released fairly clear and flavorless, or does it carry off some flavor with it? I'm thinking about tomato water, which was the Trendy Food of a few years ago, and which to me has almost no taste; I'd like to be able to separate off Peach or Nectarine Water without losing flavor components.
The liquid tastes like very sweet fruit juice, I wouldn't discard it, it has too much flavor. If your fruit is very watery, it doesn't have a lot of flavor to start with. In-season nectarines and peaches shouldn't have this problem. In my area (Boston) we don't have good stone fruit yet, I've been doing strawberry and mangoes gelati up to now.
Tomato water depends on the tomatoes you use. I slow-roast tomatoes to concentrate their flavor but any juices in the roasting pan are added to the food.
I wonder if you can slow-roast stone fruits in the same way as tomatoes - mmm, could be an interesting experiment.
A chemistry professor friend says about the same--there's a lot of flavor in the "water," but slow roasting might evaporate just water without loss of flavor. The fruit itself isn't "watery" to eat, it just doesn't have as concentrated a flavor as the berries I've been using. (Olallieberries were the best so far but Boysens and Tayberries were pretty yummy too.) I like the combination roasted and dried idea--thanks for linking to that recipe.