Hoffman was surprised to find that it only took 24 hours before his high end coffee tasted inferior to fresh ground ordinary beans. (Unless I'm misremembering details but that was the gist).

A decent hand grinder still works on a budget. It's easy to get the grind done while the water heats. Also a great thing for travel and camping.

[–] Coelacanth@feddit.nu 5 points 23 hours ago

I watched that video recently and the conclusions were actually the opposite of that: James preferred the week-old coffee from the really good grinder over the freshly ground coffee from the cheap grinder. The testing carried out on "regular people" also didn't show a statistically significant preference for freshly ground in this scenario.

The conclusion is pretty much: if you don't have a good grinder, you're probably better off buying really quality pre-ground coffee. At least if you can buy it in small enough batches. Obviously if you buy a huge bag and take over a month to use it up then yeah, it will be stale eventually.