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?