Ultratex...

...is the shit.

It's a modified tapioca starch that imparts zero flavor into food and is a great thickening agent without the gross mouthfeel one can get with too much xanthan gum. Grant Achatz of Alinea has a seminal story about Ultratex where he discusses his way of making a parsley puree.

The French Laundry’s [Thomas] Keller is not only the current arbiter of what counts as good food, he’s also [Grant] Achatz’s mentor and he catered Achatz’s wedding. Still, there’s no real secret to a Keller parsley sauce, Achatz explains. He’d puree parsley and oil in a blender and strain it.

“Then he’d have parsley oil,” Achatz says. “It tastes like parsley and oil.” Achatz instead starts with parsley juice, maybe a little water and salt. “That liquid is going to taste intensely of parsley, because that’s all it is. Then I’d thicken it with Ultra-tex 3, a modified starch that imparts zero flavor but gives it the same viscosity as oil.”

Keller, in other words, would have compromised the flavor of the parsley. Achatz believes that technology can actually deliver a purer dish.

You can take pure, unadulterated flavors and thicken them without the use of anything that will impart anything else, so that you just get the true essence of what you wanted in the first place.

Take tomatoes from Red Hill:

Peel them, puree them in a robo-coupe, hit it with a little salt, and then add Ultratex until you get the consistency you want. Voila, tomato puree that is nothing but the taste of fresh tomatoes picked that day:

After you have made a puree, you can take it and spread it out thin on a Silpat and let the mixture dry out, aided by either a low oven or stovetop. Voila, tomato "paper":

National Starch should give free samples, I would check them out if you want to get some Ultratex. If not, check Le Sanctuaire.