Psyllium Husk
Psyllium husk is the outer shell of a tiny seed, and it absorbs many times its weight in water, which is exactly what makes it so useful in the kitchen.
What It Is
These are the husks, not the seeds themselves, milled just enough to be light and slightly powdery. They come from a plant grown primarily in India, where psyllium has been cultivated for centuries. The husk is almost pure soluble fiber, which means it swells and gels when it meets liquid. That one behavior is the whole reason cooks reach for it.
Traditionally it was taken stirred into water as a simple daily drink. In the kitchen it has found a second life as a binder and thickener, especially in gluten-free baking, where it does a lot of the structural work that gluten would otherwise handle.
What To Do
In gluten-free bread or pizza dough, one to two teaspoons per cup of flour gives the dough enough stretch to hold together and chew properly. In overnight oats or smoothies, a teaspoon thickens things up without changing the flavor at all. Stir it into liquid quickly and let it sit; it sets fast. For a plain fiber drink, stir one tablespoon into a full glass of water and drink it before it gels solid, about thirty seconds.
Store it somewhere dry and sealed. It pulls moisture from the air and clumps if left open. Flavor is essentially neutral, so it disappears into almost anything.
