Grind resting time

Beginner and pro baristas share tips and tricks for making espresso.

#1: Post by GDM528 »

Do you grind and brew asap, or give the grind a few minutes to degas?

I've gathered from various postings that range from 'no, your coffee is already stale' to overnight (yikes!) - but I'm wondering if there's more established canon on post-grind resting time: a rule of thumb, or perhaps a formula to solve before drinking one's coffee.

Maybe something like: 60min / (1 + days post-roast) ?

I wouldn't consider this a substitute for the chemistry behind post-roast resting whole beans, but this may be a way to roughly compensate for excess CO2 when letting the beans rest longer isn't an option, which can sometimes come up.

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#2: Post by cafeIKE »

Coffee Rule of 15's:
  • Green coffee is good for 15 months
  • Roast coffee is good for 15 days
  • Ground coffee is good for 15 minutes
Roasted coffee needs a few days to degas. Once it has, waiting just reduces crema. Most here grind, distribute, tamp, lock & pull.
Some wait a few minutes after grinding when making pour over.


#3: Post by bbeaton »

I've never heard the rule of 15s but I like it. Is that HB lore or did it come from somewhere else?


#4: Post by skink91 »

So what is the definition of 'good' in this circumstance? (Rules like this always feel like a nearly sure-fire way to miss the real truth of things to me... easy to remember but never quite the way)

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#5: Post by cafeIKE »

bbeaton wrote:I've never heard the rule of 15s but I like it. Is that HB lore or did it come from somewhere else?
AFAIK, it's origin is lost to time, but may have originated around the start of the specialty coffee era.

Modern lighter roast coffees probably extend the Roasted time 2x to 30 days.

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#6: Post by Jeff »

Modern light roasts can be in the 20-100 day range after roast. I typically don't touch any of them for about a month. Even for filter we've had high-end coffees that were "ok" at two weeks but didn't become outstanding until 3-4 weeks

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#7: Post by cafeIKE »


How much do you buy and how often do you sample?

100 days at room temperature?
Sealed bag?

When you say filter is than an AeroPress size or a 12 cup pot?


#8: Post by erik82 »

For coffee that's more then 4 days post roast just grind and use right away. Sometimes when the beans are way too fresh (say 1-3 days post roast) you can wait a minute to let them degass a bit but that's the only time you maybe don't want to use it asap.

The only rule is that it'll stale incredibly fast after grinding so use it asap.

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#9: Post by drgary »

Jim posted this awhile back:
another_jim wrote:One thing about a roaster or importer doing formal cupping after 24 hours ... The coffees are ground, put into the cupping bowls and laid out well before the cupping starts. Then another period of time is spent inspecting the greens, the roasted beans, and the grounds. My guess is that the coffee is ground about an hour before it is steeped. After the crust is broken, it's tyoically another 15 minutes before everyone is doen slurping and spitting. This gives the coffees a chance to degas and develop, and they will loose some of their dullness and grassiness.

Also, anyone who doesn't wait ten minutes before trying the coffee once the crust is broken is wasting their time. It all just "tastes like coffee" until it has cooled to nearly room temperature. One of the many reasons cupping in groups works better is simply that enough time is spent chit chatting for the coffee to get right.
I generally wait at least an hour a day after roasting.

What I WOULD do for a good cup of coffee!

GDM528 (original poster)

#10: Post by GDM528 (original poster) »

So, maybe I can modify the formula a bit:

Grind rest time = 60min / (days post-roast)^2

Implication is brewing same day as roasting is a non-starter - skip coffee that day if necessary. I don't envy roasters that have to show up at an importer and make same-day decisions on buying a pallet of greens...

1 day post roast = wait one hour
2 days post roast = wait 15 minutes
3 days post roast = wait 5 minutes
4+ days post roast = just do it

I've been letting the grind degas for cupping sessions, and lately have been trying this as part of my regular espresso workflow. My unscientific observations so far are smoother shots with less sourness.