Rice – does it matter what you use?

A while ago I spent time researching rice as I was trying to figure out if it mattered what type I used. I was looking up the rice used in idli, the soft steamed bread used in Southern India for breakfast. There they use, surprisingly, a rice they call idli rice, and this is available through Spices of India. But did it matter what I used?

Well, I read vast amounts of food technology abstracts and decided that it did. I ordered the idli rice, used them with the urid lentils in the bagels I was developing, but gradually decided I like a mix of urid lentils and tapioca better and forgot all about the ‘rice question’, ignoring the large bag of rice in my cupboard.

Today I had a query about ‘sweet rice’ which turns up in American gf recipes. What is it and why is it used? I hunted around again, and found a clear simple explanation on http://busycooks.about.com/od/howtocook/a/ricescience.htm.

Essentially, rice differs in the amounts of two polysaccharides there are in the starch, amylose and amylopectin. To make something soft and that sticks together you want amylopectin and not amylose, which is what sticky rice has. Risotto and short grain rice also stick together rather than hardening as separate grains when cold. Long grain rice stays separate when cooked and goes hard when cold; it has the most amylose which is a long straight starch molecule.

Amylopectin is a branched polymer – so think of it as being a bunch of branching twigs tangled together. http://en.wikipedia.org/wiki/Amylopectin

Amylose is a straighter polymer that tightly packed (a bundle of straight twigs), is insoluble in water and tends to be slower to digest, bringing the Glycaemic Index down. The higher the proportion of amylase the less the gel strength (http://en.wikipedia.org/wiki/Amylose).

So, yes it does. If you want discrete grains of fluffy rice for a biriani, use long grain rice with its high number of straight molecule that stay stiff and tidy. If you want to be able to pick up a ball of rice with chopsticks, or have a soft cold rice pudding, or make gluten-free bread that is soft and holds together, go for the gelling qualities of the short grain rice, the one with the tangled web of branching molecules.