Over the last few days we've hosted a friend whose husband was undergoing surgery at a local hospital. She wanted her four cups of half-caf drip coffee in the morning. I wasn't about to grind it by hand in my LIDO. So I mixed some home roasted decaf and caffeinated beans, dialed the Super Jolly to coarse and ground enough for her morning brew. I immediately sealed it in a small bottle and tossed it in the freezer. The next morning I brewed it for her and she loved it, several days in a row. I didn't taste it, sticking to my fresh ground coffee. But this got me thinking.

A few months ago I visited Alana's Cafe in Redwood City, which advertises its "gourmet coffee." They get their own blend of Mountanos Brothers, and they prepare a drip brew that tastes like a fragrant, fresh, medium roasted Guatemalan. They sell this coffee in bags but I learned they only get it pre-ground, so I didn't buy any to take home. I wondered, though, why it tasted so good. What about Babbie's Rule of Fifteens, which says that coffee brewed 15 minutes after grinding is stale? I wondered if this is the case when a pound or more of coffee is sealed in a bag where there's no place for the aromatic flavors to escape? Then I came across this discussion today in a current thread about Blue Bottle Coffee:

Intrepid510 wrote:Has anyone ever had a good experience at one of their Farmer Market locations? Obviously I haven't and I really should know better. Went to their stall at the Marin Farmer's on Sunday, just awful, would've gone back to ask for a refund had I not had my children with me. Preground coffee coming out of their bags without a grinder in sight, tasted stale to me like it was ground early in the AM.

With their apparent commitment to quality at their stalls that I have experienced it looks like they are going to give Starbucks a run for their money with their current influx of cash...

Nick's post was followed by a reference to an old thread where Abe Carimali, Jim Schulman and others took a lead from Scott Rao and found in some cases that pre-ground coffee, especially if it's fresh, can taste better. What follows is a comparison of pre-ground fresh coffee, pre-ground coffee that's already been rested in whole bean form, and espresso versus a brew pot. Some posters suggested that aging of whole beans is comparable but slower than pre-grinding fresher beans. Several reported that espresso extraction was more sensitive to pre-grinding than immersion brew. Here's that thread:

Experiments with Preground Coffee for Espresso and a Brew Pot

All of this leads me to think more flexibly about aging and pre-grinding. Perhaps I can buy a bag of fresh-roasted, pre-ground Mountanos Brothers coffee at Alana's and it will still be fine for drip, especially if I quickly freeze it airtight. Maybe I can get an earlier taste of home-roasted beans if I grind and let them rest awhile to round out and integrate the flavors up to 12 hours. Perhaps I can even pull some espresso of fresh home roast, especially if I grind coarser and updose. In any case this has me reconsidering the Rule of Fifteens, that green coffee is stale after 15 months, roasted coffee is generally stale after 15 days, ground coffee is stale after 15 minutes, and espresso is stale after 15 seconds. I haven't always found the last three to be true and don't have enough experience storing greens to have a take on that. Some lighter, acidic roasts especially need a lot of rest. I think I'll relax a bit and taste what works for the particular coffee and brew method I'm using.

What do others think about this?

I do think it's good to keep one's mind open to the possibility that Babbie's Rule is just a guideline and wasn't found inscribed on a clay tablet in Ancient Sumer!

In the past, I've had very good results in the cup when grinding freshly roasted coffee straight into a Ball jar and then sealing it up for storage overnight at room temperature before brewing. Why? Chicken thigh. Didn't want to wake a sleeping newborn with the Preciso's racket at the time--now she's used to such noise, so it's all academic for me.

I'll follow this thread with interest (thanks).

Grinding freshly roasted coffee and letting it sit is one way to speed up the aging process. We all know freshly roasted coffee needs to rest a couple days to develop. If you take that same freshly roasted coffee, grind it and let it sit for a while you artificially age the coffee. The increase in surface area accelerates the out-gassing and oxidation of the coffee. So in some cases pre grinding ultra fresh coffee will get you a better cup, or let the whole bean sit and rest for 4 (or whatever that particular bean requires) days.

Dave, what you say makes sense if it rests on the order of magnitude of minutes. Do you have any first hand experience? I'll try it next week when I do an espresso roast but am on a learning curve with my ugpraded hottop

Marvin

If I may, I would love to suggest a sideline of experimentation here regarding tamping vs. not tamped (i.e. for people with doserless grinders such as the Vario). Sure, you could grind and let it sit in a fluffy pile, but if you're bother to pregrind, it makes sense also to clean up a bit after grinding (my Vario sprays a bit at the end of each single dose.)

So the side question is: How does tamping affect the exposed surface area oxidation rate of coffee for espresso?

My caffeine dependence and finicky newborn combine into a limiting factor for my capacity for experimentation, but I figure I'd toss this into the convo as food for thought. Thanks Gary for reviving this line of inquiry!

iginfect wrote:Dave, what you say makes sense if it rests on the order of magnitude of minutes. Do you have any first hand experience? I'll try it next week when I do an espresso roast but am on a learning curve with my ugpraded hottop

Marvin

I have but only when I am out of coffee and just roasted a fresh batch of espresso the night before. I will grind into the doser and come back in 15-30 minutes then prepare my shot. The coffee has still not fully developed but you do get accelerated out gassing and some development. Think of it in terms of tomatos. You can get a red tomato and you can get a ripe tomato. One was picked green and gassed red the other ripened and turned red on the vine before being picked. Ground coffee will speed up the out gassing and accelerate the aging but not necessarily accelerate the development. It is an emergency fix for an emergency situation.

cannonfodder wrote:Grinding freshly roasted coffee and letting it sit is one way to speed up the aging process. We all know freshly roasted coffee needs to rest a couple days to develop. If you take that same freshly roasted coffee, grind it and let it sit for a while you artificially age the coffee. The increase in surface area accelerates the out-gassing and oxidation of the coffee. So in some cases pre grinding ultra fresh coffee will get you a better cup, or let the whole bean sit and rest for 4 (or whatever that particular bean requires) days.

Great summary, Dave. Later when asked about your experience with this you write:

cannonfodder wrote:I have but only when I am out of coffee and just roasted a fresh batch of espresso the night before. I will grind into the doser and come back in 15-30 minutes then prepare my shot. The coffee has still not fully developed but you do get accelerated out gassing and some development. Think of it in terms of tomatos. You can get a red tomato and you can get a ripe tomato. One was picked green and gassed red the other ripened and turned red on the vine before being picked. Ground coffee will speed up the out gassing and accelerate the aging but not necessarily accelerate the development. It is an emergency fix for an emergency situation.

This leads me to think there may be an in between circumstance. A coffee has been aging for a few days but is still a little harsh. Then maybe you can pre-grind to mellow and integrate the flavors but at this point you're just dialing down the harsh edge and you won't taste an inferior shot. This gets into an area of good cooking where you adjust by taste using the techniques available to you. It would be hard to suggest guidelines other than practice and experience. What do you think?

If you try it make sure you do it blind I've also been wondering if grinding freshly roasted coffee would help off-gas it more quickly so one could try it right away; but since I'm new, I'm following general convention until I get my sea legs.

On a similar note, last year my gf wanted to have small cups of coffee at her last workplace, but there wasn't a way to grind the coffee (hand grinder out of the question). We did a blind tasting, first pre ground coffee and then sealed in air-tight ceramics that were just large enough for a single dosage. Didn't freeze anything. Brewed it a few days later and compared to fresh ground of the same bean, without knowing which was which. There was a difference, but one wasn't better than the other. There was a noticeable difference favoring fresh ground after ~7 days.