A guy at the coffee shop in Boise said he could tell the roast date by the bloom

I was at a place called Slow By last week and a man next to me watched me pour. He pointed at the grounds and said, 'See that weak bloom? That's at least three weeks off roast.' I've been checking dates on bags ever since, but is that a real thing or was he just showing off?

3 comments

3 Comments

angelab622mo ago

Bloom can tell you some things, but not an exact date. It shows how much gas is left in the beans. A super active bloom often means a very fresh roast. But a weak bloom could just mean the beans were pre-ground, or your water wasn't hot enough. That guy was probably half right, but also making a guess to sound smart.

zara_miller2mo ago

Oh yeah, @angelab62, I read that exact thing in a coffee book last week!

charles_kim1mo ago

Wait, hold on. That guy...he was actually HALF right? That's WILD to me. I always figured those coffee shop folks were just blowing smoke to make themselves look like experts in front of people. But you're telling me there's actual science behind the bloom thing? I totally bought into the idea that a weak bloom meant old beans. That part about grind size or water temp being the real culprit changes EVERYTHING. Guess I gotta give that snob a little bit of credit now, even if he was being a show-off about it.