It was a good discussion... I've merged your thread with this one to bring it back to the top of the Coffee forum should others wish to comment. BTW, this thread and a few other notables are in the forum's FAQ.

I think there's one important factor that's been missed in these discussions -- we don't consume the coffee instantaneously, rather it can take anywhere from 3 to 7 days.

For instance, the practice of Intelligentsia of holding their storebound Blackcat at the roasterie for three days, because it's at its best on day 4 and 5, relies on a roasting and use schedule that can accommodate this precision. If the same black cat is horrid on day 6 and passable on days 2 and 3, a home user is better off having it too early than too late.

My personal opinion is that nothing much good happens to light roasts after they come out of the roaster. For espresso, one may need to wait a day or two to get away from over-exuberant crema, but a larger cup and naked PF may be the better solution than having it stale by the sixth day. In other words, start consuming your light roasts well before they hit perfection.

On the other hand, darker roasts can emerge from the roaster with an acidity that's kind of crude, and roast tastes that have over the top and jagged pine, camphor, or turpentine aromas. They may improve dramatically in four to six days as they mellow out. Also since the fruits and flowers have all been roasted out in any case, there's no loss of origin flavors to worry about, and they can usually go a few weeks without noticeably declining. In other words, with dark roasts, age to perfection, then start consuming.

barry wrote:i believe that degassing is the first stage in staling, as the more volatile aromatics are lost with the CO2.

I think that coffee loses its soul after degassing.

Ken Fox wrote:I do a fair amount of freezing, however, of which I am a proponent if it is done right. Doing it right to me means that the freshly roasted coffee, straight out of my sample roaster, is in a sealed mason jar in a very cold freezer within an hour of the end of the roast.

This is exactly what I do and it allows me a decent quantity roast of 3+ lbs. while not sacrificing the quality of the beans' "aging". Although I do enjoy a couple espresso blends fresh out of the roaster and continue to equally enjoy them as they "age" for the next several days to a week.

I guess one could conclude this: It is all perception and taste, what I think is an exceptional roast my wife may think is way too sharp or my son may think is too bland... I sometimes prefer the European style of sweetening my espresso and at other times would never even consider it. I may love one roast more at 4 days then at 2hrs. or one week while another roast I may only enjoy after 4 days. (Some roasts hit the 'circular file' after a couple of tastings!) Ah...the joys of home roasting...

What every person here has done in posting their knowledge, opinion and expertise, is to truly engage in a enlightening and informative train of thought. It has been a great read, thanks!

Psyd wrote:Could pressurising a container with CO2 stop that process and therefore keeping beans from going stale?

Gosh, now you have me thinking. I homebrew beer, and one of the many contraptions I have to assist in that process is a 6-liter bottle pressurised with 2 CO2 cartridges (the Tap-A-Draft dispensing system). I could easily load roasted beans into a 1-2-3-6 liter soda bottle and pressurize it with (approx) 15 PSI of CO2 (the pressure would be higher for smaller volume containers ... Boyle's Law, don't you know?).

If the beans outgas quite a bit, there's a pressure relief valve built into the mechanism -- but I can't believe that even a large batch of beans would trigger the pressure relief valve (I could be wrong, of course -- I customarily am).

Naturally none of this is quite as convenient as storing my roasted beans in Mason jelly jars (cranking them tight after a day or two), or even one-way-valve plastic bags -- or even one-way-valve modified Mason jars. But it would guarantee a positive CO2 pressure on the beans.

Maybe it's all just a pipe dream: my typical roaster batch doesn't last long enough to stale, even if I left the naked beans out on the countertop, loose (an exaggeration, of course -- but 3-4 days is the usual max lifetime, depending on brewing method).

t++

We had an interesting discussion around this same subject at our last Friday get together at CCC. I seem to recall Bob Barraza mentioning that he had read that the cellular partial pressure of CO2 in freshly roasted beans was in the neighbourhood of 130 to 150psi. If that's the case then 15psi wouldn't probably do a lot to slow the CO2 release. It would be interesting to find out just what pressures the beans do experience.

Cheers

Ian

woodchuck wrote:We had an interesting discussion around this same subject at our last Friday get together at CCC. I seem to recall Bob Barraza mentioning that he had read that the cellular partial pressure of CO2 in freshly roasted beans was in the neighbourhood of 130 to 150psi. If that's the case then 15psi wouldn't probably do a lot to slow the CO2 release. It would be interesting to find out just what pressures the beans do experience.

Bob is right; the pressure is surprisingly high.

I think Illy cans are pressurized with nitrogen at around 35psi (their book says up to 2.2 atmospheres) and certainly have a safety valve. I guess cans that work up to 150psi are too expensive to be disposable. However, Illy, like other Italian roasters, thinks a certain level of outgassing is required before beans are at their peak. They imply that their packaging allows this level to be reached and held. So maybe 35 psi partial CO2 pressure is the "optimum" level for espresso.

how about installing a schrader valve from a bike tube in the lid of a mason jar.

insert fresh roasted beans in jar.

wait.

use tire pressure gauge on the valve to see the pressure.

use valve to put in or take out pressure.

patent applied for.



jon

Just tasting a pretty old (maybe up to 1/2 year) Mauro Concerto (commercial roast from Italy; http://www.caffemauro.com/) pushed by my little Classic. The bag is opened yesterday.

Well, all I can say; It's amazingly good. It's a dark roast. With lots of robusta in it. So there are only a minimum of volatile acidic fruity tones even at the start (as it should be for my taste). But it sure has a great deal of chocolate and power smoothed together. Works very well together with or w/o milk .

I would rank the coffee much higher than my own home roasts.

So maybe the most important thing still are; 1. Skills of the person who blends & roasts. 2. Good storage.

That's my view (hope I don't upset anybody)


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I should add: The crema is magnificently silky-smooth & not fluffy and tall .

Hello!

I've bought some beans this afternoon that came right out of the roaster. I just tried them (I know, they've only rested for 7 hours but I couldn't wait) and I must say I don't quite like what I'm tasting:

+ syrupy
+ tigerstriping and speckles in the crema
- Very very very sour
- extraction starts all crema but the crema dissipates very fast and a couple minutes after the extraction the crema has reduced to about 1mm and can't support a spoonful of sugar anymore
- crema contains very large bubbles

Are these typical signs of beans that are too fresh or is this a quality of this particular roast (especially the sourness which is simply unbearable if it remains this way)? The extraction ran for 25secs and gave about 40ml or 1.3oz.


I'm terribly sorry if this kind of question has already been asked in this topic, I must admit that I haven't read all the posts.

Thanks in advance!