Instant Soybeans?

In an effort to figure out whether it's just me, or that the store bought soymilk taste diluted, I decided to make some at home. My mom used to make it at home years ago. Got myself some soybeans from Fairway's upstairs Organic section. Soaked the soybeans with cold water. Here's the strange part. Within 5 minutes, the beans were soft! That can't be. I called my mom, who said I need to soak the beans for at least 8 hours, which is how I remembered it, too. She was puzzled, when I told her how these soybeans are behaving.

Are there such thing as "instant soybeans"? These seem smaller, and quite flimsy. I want those big soybeans that the Korean soybean sprouts sprout from, not these mushy ones. Can anyone help?