30 seconds is indeed the _original_ Aeropress recommended brew time. [1] You're supposed to mix the grounds and start plunging nearly immediately, finishing in about 30 seconds. So, indeed, much of the water passes through even before 30 seconds.

That was way too short. It looks like they've finally updated the instructions somewhat, now recommending 60 seconds before starting to plunge. [2]

It works because they also recommend a very fine grind, but that's still pretty short. It looks like Counter Culture recommends using regular pour-over grind and the inverted method and 2-3 minutes, [3] which happens to also be what I do. Though I'm not really particular, so long as it's somewhere between about 1.5 and 3.5 minutes. (Breakfast is a hectic time while also handling kids...)

1. https://www.seattlecoffeegear.com/pages/product-resource/aer...

2. https://aeropress.com/pages/how-to-use

3. https://counterculturecoffee.com/blogs/counter-culture-coffe...