Marshall wrote:I'm going to at least slightly disagree with everyone who has answered the O.P. In no particular order:

1. No, there is no single ideal resting time for all beans, blends and roasts. If a roaster has given you the benefit of their experience and made a recommendation, consider yourself blessed and follow it, EXCEPT THAT coffee bars (their main customers) will use an entire bag on the same day that they open it, while consumers are likely to take a week or more to consume the bag. If that applies to you, I would time my usage accordingly and maybe open the bag a day or two before the target date(s).

Marshall makes a great point here. I've been testing resting times for some blends I'm developing and just had a lengthy discussion on this topic with a visiting friend who is a fellow espresso enthusiast. He's a Black Cat fan so I used their average 8 to 10 days optimal rest as an example. They are roasting and blending every day and when a given batch that is resting for use in their own cafes hits optimal level I assume it all gets used within a day or two.

With my low consumption during testing phases (just me making three or four shots per day and the few occasional visitors) my practice is to split a given blend into several batches of 8 oz each and freeze the ones I'm not ready to use yet. I've been comparing freshly roasted and blended as it sits in the hopper and I try it on subsequent days to the results I get form a sealed valve bag of the same blend that sat on the counter for 5 to 7 days before opening. It is unquestionably a smoother, better and more rounded flavor profile after a week of rest but the fall off in quality after the bag is opened starts to occur within three days.

I've been supplying a local friend with a variety of drip coffees since getting the roaster up and running. She drinks exclusively vac pot and has been loving the coffee but she commented that the Kenyan Riuku Peaberry exhibited a fall-off in flavor far more rapidly than the Guat, Yemen and Brazil beans I had provided her with in previous weeks. The Kenyan was roasted darker than the others so this raises my interest: can roast level affect longevity of the best and most distinct flavors in a coffee or is the varietal itself more likely to be a cause of this phenomenon.

I use Mason jars and usually roast at night. The roasted beans go into the jars and I keep the lid loose on the jar. In the morning I tighten down the lid and then every morning after that I usually open the lid briefly to relieve the pressure (and usually take some coffee to brew). I've found that I don't have to relieve the pressure every morning, just leaving it loose the first night is generally enough.

Marshall wrote:I think that misses the point of the question. 5 resting days sitting in a sealed bag are different from 5 resting days in a bag that is repeatedly opened. I would multiply opened bag days by some factor (2?) to approximate an equivalence to sealed bag resting.

It's a little more complicated.
Keep in mind that the aging process is a combination of degassing (which occurs regardless of what kind of container the coffee is stored in), oxidization (exposure to oxygen which varies depending on container), exposure to heat (which is independent of container) and exposure to light (which depends on container).

yakster wrote:I use Mason jars and usually roast at night. The roasted beans go into the jars and I keep the lid loose on the jar. In the morning I tighten down the lid and then every morning after that I usually open the lid briefly to relieve the pressure (and usually take some coffee to brew). I've found that I don't have to relieve the pressure every morning, just leaving it loose the first night is generally enough.

thanks

Hey Phil,
The best way to learn is to try it at all different levels to get a flavor memory. I drink coffee still hot out of our roaster, take notes, drink it the morning after, take notes, and throughout the next week I am mentally comparing the coffee. It is hard to put a standard on anything due to the volatile chemistry of coffee. So many factors affect the outcome, from altitude, processing, the age of the harvested green coffee before roasting, the roast profile itself as well as the roast type (drum, air, combo).
Some coffees are great after a night (about 8 hours) of rest. Some coffees, especially when being used for espresso, you definitely will want to give a few days minimum rest. I will give recommendations for our customers for specific coffees.
But the best advice I could give you is for you to train your palate. Drink it at all different times, right away, day after, few days after, etc. Take some notes. You are looking for a baking soda-y type of mild unpleasantness. When your palate is nice and developed, you will be able to grab a cup the day of and estimate with great accuracy how long it will need to degas.
Best of luck!

My new routine is that when I buy a pound I immediately divide it into 3 or 4 ziplock bags which go into the freezer. I remove one bag at a time and empty it into my VacuVin container and pump the air out. I open and reseal the VV each morning for the 3 or so days it takes me to go through the beans. I find this provides nice, consistent results that generally don't require any tweaking of the grind settings.

As a homeroaster I know what each of the beans are and how they were roasted. Each component will have its own life cycle. Ultimately I would need to stage the roasts to align the varied maturations. Instead I'll roast up several components and mix/adjust to taste as they age. If I have one that is slow I'll burp out the collected co2 more often. Not knowing what's mixed in your first bag of a blend makes it's tough to guess how it should be treated.

Pretty much agree with Ed and Marshall. I buy two lots of around 4-5 x 250g bags per month and then work my way through the beans in terms of when they get to their best. Some are good to go after a few days in the post, some can take ten days to come on song and then only stay there for a few days... Others stay on song for ages....

Happy Christmas!

Mike

HB wrote:I use Mason jars and seal the lid airtight. It will "burp" when it's reopened. You could outfit a one-way valve (e.g., as shown in Home made 1 way valve jars), but I've never bothered since I don't homeroast.

Thanks Dan

The interesting observation is, when I compare home roasted HotTop vs Mini500 beans, the flavors "mature" at different times. For example, I just had some Ethiopian Sidamo roasted 12/13, with the Hario V60, and the typical berry flavor is still present. However, when I tried the coffee on day 3, it tasted gassy and grassy.

The Paradise Espresso Classico behaves similarly. The HotTop roast has good flavor at day 3-4, but the Mini500 roast does not taste good until day 10.

Generally, darker roast stales a bit faster. Although coffee flavor loss is mainly due to loss of various thiol compounds, and not staling of coffee oils per se, with darker roast, due to the lipids closer to bean surface from the dragging outward migratory effect of carbon dioxide, the oxidation of lipid is faster, and therefore faster rancidity with darker roasts.

I am puzzled why electric vs gas roasted coffee will have different resting period.

sounds more like a roast defect issue to me.

Probably. I still have much to learn about roasting and cupping. Maybe I'll sign up for Willem Boot's class someday. I just wish he has a consumer class instead of courses geared toward professionals.

What intrigues me also was that Coffee Klatch espresso blends taste more balanced 2-3 weeks post roast.

I've been experimenting with different roast profiles. From my limited experience at this, it would appear that a slower roast needs less time to degas, with a faster roast needing more time. This also ties in with the coffee aroma immediately post-roast. The slower roast, at the far end of the scale at 20 min, smells coffee-like straight from the cooling tray whereas the faster circa 13 min roast smells more grasslike, which was not dissimilar to coffee straight from my old iRoar.

So, could it be that the electric vs gas difference mentioned is possibly roast profile rather than heat source related?

Heat type application will effect the degas process as will the profile and degree of roast. Going into 2nd crack will cause more bean fracturing and co2 release.

So, after thinking about this thread for a while, I searched Journal of Agriculture and Food Chemistry. This 2008 article was one of the more informative research on temperature and time relationship, with different roasting methods. In the article, a Probat drum was compared with a laboratory fluid bed roaster. There was also a reference to a German article published in 1989 which discussed different roasting methods/energy source and rate of staling.

The article is here:
http://pubs.acs.org/doi/abs/10.1021/jf8...istoryKey=

There is a difference in the amount of formation of aldehydes and various sulfur compounds when the roasting methods are different, even though the beans were roasted to the same degree by near infrared examination. This basically translates to different "degas" or peak flavor time. One of the ideas regarding determining the degree of roast was by measurement of sulfur compound, instead of using near infrared to measure color, such as Agtron.

The experiment also examined various chemical profiles if a fluid bed and drum roaster followed a similar time-temperature profile, and found them to be similar. From what I can infer, it means the roasting profile and degree of change of temperature will affect the rate of staling/degas.

I've used beans just after roasting (<1 day) and they are always less than fully enjoyable...the taste is "gassy" (somewhat harsh and strident) and the crema is thin, bubbly, and collapses quickly.

Still, an imperfect shot is still a shot and can be enjoyable (on some level). I find my own blends need to de-gas for at least 2 days and are at their best after 3 days.

Also, for some unexplained reason, the heat sealed bags with 1 way air valve provide a better taste even if the beans are bagged for a mere 3 days.

Len