It’s actually a biochar from spent coffee grounds. Biochar is a process of slow burn in a low oxygen environment.

So 1: it doesn’t resemble coffee by the time it’s put in. Closer to charcoal. Cute jokes about how nice the concrete will smell are fun, but off base.

And 2: Coffee probably isn’t the only base you could use for the biochar. It makes for a cute fuzzy headline that people love to share but it could prove more effective and economical in the end to make a biochar out of lentil chaff or something else. We need to see this put into practice at scale before we have any idea if gathering up coffee grounds from cafes to make concrete makes sense at all.

This is actually a pretty cool idea especially given the issues with getting sand for use in concrete.

I bet it shakes when it cures

Wow I didn’t know it was a large contributor to greenhouse gasses. Good if it can be reused in concrete and save habitats from sand mining at the same time.

Gotta say, my lawn loves my spent coffee grounds. For those of you who have some green space and don’t want to trash your coffee.