How long does uncooked rice (like the one milled and just packaged in bags) actually last?


I’m from an Asian country that loves rice, but now that I think about, I’m not actually quite clear what gives rice its longevity. Common wisdom here is as long as it doesn’t get insects, get mold, or otherwise change from being dry it should be fine to cook and eat. Otherwise, it can simply sit in a bag or a storage container without apparently spoiling.

How does it do this? I’m aware that it doesn’t last forever, but it sure stays edible (as long as its uncooked) for longer than I expected.

In: 737

Milled rice longevity owes to the husk being removed. The husk has oil that goes rancid. Dry white rice has a shelf life of two years, brown rice goes bad at 6 months.

There are, broadly speaking, two ways food goes “bad”

First is bacteria and fungal/mold growth. Both of these require water to survive. Dry rice has no water so mold and bacteria can’t grow and therefore never make the food go bad. Or at least are very slowed down from making the food go bad.

Second is a chemical reaction called rancidification which is when fats and oils chemically react with the air and become really gross. Rancid oils are usually less acutely dangerous that moldy food but it’s still bad. Which is to say eating the wrong kind of mold can kill you in a day but rancid oils just make you sicker and sicker over a long period of time.

Rice (at least white rice) is immune to both of these because it is very dry and also has no fat.

I had a friend from Vietnam in HS, and I asked him why does he have a hamper in his kitchen. He kicked it open and it was filled with rice. I knew he ate a lot of rice, but I wondered if it went/ could go bad. This post reminded me of that memory.

Basically, it comes down to what it means for food to go bad. Food is bad if it’s

A) Got mold or something else growing on it.

B) Got fats in the food that go rancid in open air.

Now, mold and bacteria need water to grow, but uncooked rice has little to no water; so if kept dry, nothing will grow on it

Next, white rice is just brown rice, but with the bran & germ removed. Since that’s where most of the fat is, white rice has very little fat to react with the air.

Tldr: White rice is shelf-stable because it has neither of the things that allow food to spoil. No water for mold, no fat to go rancid. Keep it dry and sealed, and it’s gonna be virtually fine