Why coffee needs to ''rest'' before making espresso - Page 3

[Ken Fox]

While the coffee may be losing some aromatics while it rests, you seem to ignore the fact that the oils and sugars continue to combine, develop, and change after roasting for a period of time. The flavor development of the beans doesn't stop at the moment the beans have cooled to room temperature.

By using the coffee immediately, you've not given the chemistry in the bean that was started by roasting time to finish. Flavor development is really a better term than "staling" - which is neither accurate nor descriptive of what is happening within the bean after roasting. Staling means to be made unpalatable from age.

If coffee develops better flavor because you've allowed the chemistry that was started by roasting to fully finish - that, by definition can't be staling as the flavor has been improved and not degraded.

I've avoided participating in this thread because I wasn't sure I really had anything substantive to say that had not been said. But I do like your last sentence as it more or less sums up my opinion.

There is a point in the aging of coffee where nothing good can happen and only bad will happen. For me, that point seems to come around day 10 after roasting if the coffee is to be used for espresso. Since I don't drink very much coffee prepared by other methods I won't try to extrapolate my espresso experience to these other techniques other than to say that most people think that the point after which nothing "good" happens is a few days longer for these other brewing techniques.

To me, staling is what happens to the flavor when the roasted beans have completed whatever positive evolution they can complete, and only bad things can happen. It is analogous to what happens to wine as it goes "downhill," such as most California white wines held for more than 2 years. But then, you can age an Alsatian Riesling or a real French Chablis for 20 years and for most of that time positive things can balance out or even overpower whatever "bad" is going on.

Staling is a very loaded term that assumes that all oxidative reactions are "bad." If this were true the marketplace would not support such products as tawny port, or aged cheeses, and we'd be much the poorer for it.

ken

[Psyd]

I posted on CG questioning the relationship of outgassing and staling. Is the CO2 escaping the bean related to staling in the first couple of days and oxidation after that? Is internal pressure of the CO2 in the bean what drives the outgassing? Could pressurising a container with CO2 stop that process and therefore keeping beans from going stale? Bob Bazzara started me thinking along these lines, but left off before actually hinting at the answers to these questions. Anyone else able to contribute actual data or are we waiting for Bob to get back here?

[another_jim]

I posted on CG questioning the relationship of outgassing and staling. ...Could pressurising a container with CO2 stop that process and therefore keeping beans from going stale? Anyone else able to contribute actual data or are we waiting for Bob to get back here?

Buy a can of Illy beans and decide for yourself.

[Psyd]

Buy a can of Illy beans and decide for yourself.

I've had the Illy beans, and I wasn't overly impressed. They weren't horrible, but I've had better from our local roasters here in Tucson. Does Porf Illy pack his beans in cans pressurised with CO2?

[another_jim]

Does Porf Illy pack his beans in cans pressurised with CO2?

Pressurized nitrogen; it's cheaper and just as inert. This prevents outgassing and oxidation, but not other staling processes. I and many others have the impression that Illy suffers from coffee progeria. The coffee is fresh when opened, but stales in 2 to 4 days, rather than the usual 10 days to two weeks. I'm guessing that the long storage leads to degradation of the coffee's cellulose lattice, and hence the outgassing and oxidation is much more rapid once the can is depressurized.

For bar use, which is where most of the coffee goes (2 kilo cans that plug in as grinder hoppers), the accelerated staling is not a problem, since the coffee is used up quickly. But if you don't go through the domestic style 12 ounce cans in a few days, staling will become a factor.

Illy is basically a very light Northern style blend: citrus, flowers, toast and a hint of caramel; not everyone likes it, whether fresh or stale. However, staling degrades the taste of this type of coffee much more quickly than one with deeper flavors. This may be the reason that they've sunk so much more into preservation technology than other Italian roasters.

[KarlSchneider]

There is a point in the aging of coffee where nothing good can happen and only bad will happen. For me, that point seems to come around day 10 after roasting if the coffee is to be used for espresso.
ken

Ken,

I would add some details to your point here. If we plot taste quality on the y-axis and time in days on the x-axis I think we would get an irregular graph. It would show rapid increase in quality over the first two or three days, then a level plateau for about 3 or 4 days then a steady decline in taste quality of varying rates of change. I would identify your "point after which only bad happens" at about 6-7 days. Somewhere in that time frame a roast loses its single quality and becomes generic -- a Brazil Faz. Cruz Branca becomes generic Brazil. Some roasts lose quality more rapidly than others in the 6-10 day window.

One can see similar graphs about wine in Jancis Robinson's Vintage Timecharts (plotted in years not days).

KS

[Ken Fox]

Ken,

I would add some details to your point here. If we plot taste quality on the y-axis and time in days on the x-axis I think we would get an irregular graph. It would show rapid increase in quality over the first two or three days, then a level plateau for about 3 or 4 days then a steady decline in taste quality of varying rates of change. I would identify your "point after which only bad happens" at about 6-7 days. Somewhere in that time frame a roast loses its single quality and becomes generic -- a Brazil Faz. Cruz Branca becomes generic Brazil. Some roasts lose quality more rapidly than others in the 6-10 day window.

One can see similar graphs about wine in Jancis Robinson's Vintage Timecharts (plotted in years not days).

KS

Of course all of this is a matter of personal taste. The great majority of the time, the coffee I drink is between 3 days and 7 or 8 days old. It is rare for anything much older than a week to be in my grinder. 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. Beans frozen this way will continue to degas when you take the jar out of the freezer and let it reach room temperature again. I personally can't tell the difference other than that the beans don't absolutely stop maturing in the freezer, just the process is markedly reduced, so if you take out 1 month old beans from the freezer they may be the equivalent of a couple of days old in the aging process had they never been frozen. With previously frozen beans, they never stay frozen more than 3 months (usually, it is seldom more than 6 weeks), are kept at at least -10 degrees Fahrenheit, and are not repeatedly defrosted and refrozen. Generally I defrost the previously frozen beans and they are used up within 4 days of having been defrosted.

So, I don't have much experience with 10 day old beans although I would not automatically toss them as I would 11 day old beans

(actually true; you have to have cutoffs in your life at some point)

As to Jancis Robinson's comments on the aging of wine; I haven't seen them but she is a superstar wine critic. I can say that with wine and with coffee, you can't speak in absolutes since storage conditions differ. I live in a dry climate where it is seldom hot. This likely has an impact on how rapidly coffee deteriorates after it is roasted. As to wine, I have an underground storage area whose temperature ranges from 50F-59F over the course of the year with the great majority of that time spent at the lower end. When I look at vintage charts such as the ones that Robert Parker puts out every few months, invariably I find that my wines are less evolved, less ready, and much less likely to be "over the hill" than his chart would indicate. Storage conditions matter and I think this is not just true of wine, it is true of coffee also.

ken

[peacecup]

...merged with thread on related topic by moderator...

I've sampled some SO coffees with my lever machine, but have come back to espresso blends. I'm fortunate to have a great local roaster from whom I can buy coffee the day after its been roasted. I've been trying to get a sense of how the beans age, when they peak, when they're getting a bit old. I seem to like the coffee best the first week, but this may be due to the fact that it produces much more creama early on.

Anyone have an opinion on rest times and aging of espresso blends? How does roast, bean type, etc effect resting time?

PC

[cannonfodder]

Take a look at the Why coffee needs to rest before making espresso thread.

[peacecup]

Well, that answers that...Thanks.

[HB]

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.

[another_jim]

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.

[Layvodvo]

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.

[TUS172]

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!

[tmaynard]

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++

[woodchuck]

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

[another_jim]

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.

[RegulatorJohnson]

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

[Arto]

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 .

[Merlino]

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!