So on the retail level…

If coffee is harvested between May and October, when would a roaster in the US expect on avg. to receive their coffee from origin? and how long (I understand this is subjective, so I’m just asking for an opinion) should that roaster offer that particular coffee?

I also have the same question for coffee that is harvested between November and April.

But,
If Intelligentsia tackles seasonality by grouping coffees into In Season and not In Season, which is decided by whether a coffee TASTES fresh or not so fresh… I see that as fairly well-grounded. It makes me feel secure when selecting coffees.

I notice that many consumers are still very confused about raw coffee age. They still blame hallmark agey flavors on other things such as brewing. I imagine a simple stamp will eventually help clear things up a bit.

Some talented people and some sensitized people often taste ageyness in great coffees before they even leave the country of origin. That’s putting it mildly.

Being a bit more experienced than the average consumer, I won’t put myself in the way of torture by buying a coffee without having an idea of when it was harvested. And then there’s the thing about treating others as you wish to be treated.

There was a professional experiment that revealed that when a certain coffee was dried at too high a temperature, the cellular structure (I’m guessing certain lipids, proteins and carbohydrates more than cellulose-like fibers) began to fall apart. If anyone’s interested, I will go searching for the paper. I often wonder if a similar degradation would happen if the moisture gets below, say, 8.5%. Doesn’t oil crack when it becomes “dry”?

You said:

Is it linked to processing? Geoff Watts once told me a little theory he had, which I won’t repeat because a). I was a touch inebriated when he told me so I might get it wrong and b). It is his theory to tell, not mine and c). He may well have changed his mind. It was, however very much linked to the results of processing before being stored in parchment. Please Geoff, if you ever read this, correct me if I am wrong. I know I am being a bit general there.

My feeling is that the rate at which a given coffee bean ages/decays/degrades is most probably a function of (in no particular order):
1. The total moisture content within the seed. I’ve noticed that coffees which push up towards 12% average humidity seem to have a tendency to age more quickly than those which are closer to 10%.
There is some anecdotal evidence to support this. I’ve heard talk before from 3rd-generation farmers who claim they sometimes ‘over-dry’ (to 9.5% instead of 11.5%) if the customer is willing to pay for the weight difference, and they believe this to be better for the coffee (speaking of which, there is an important economic issue here–coffee is priced by weight, in nearly every stage…the more moisture the heavier the coffee…you see what I mean).
In general I’ve found Ethiopian coffees to hold up very well over time…washed Ethiopians that is ;)…as compared to other coffees I’ve imported at the same time. They tend to come in around 9.5-10%, whereas many of the other coffees we receive come in at closer to 11.5%. So I’ve begun to believe based on these types of experiences that coffees are probably more stable between 9-10 than between 10-12%. The anecdotal evidence seems to support that. Another thing to consider when thinking about this is that most moisture readers are taking an Average humidity. In reality it is likely true that there is a range of humidity within any lot of coffee, and that not every bean is exactly the same in moisture content. Some might be 11, some might be 13, and you’ve got a reading of 12…so the higher you come towards the upper limit the more risk there is that some of the coffee is too moist.
2. Water Activity. Not all of the water inside the seed is equivalent. Some is ‘bound’ molecularly within the coffee, and some is ‘free’–meaning that it can migrate around through bean. Water activity meters measure the ratio of bound water to free water, and give greater insight into what the water is actually doing inside the bean. It makes sense that bound water (which cannot move—it is attached to other molecules) is less of a threat to cause damage within the coffee than the water that is active. I suspect that this measurement will become more important in Specialty coffee in the future as it becomes better understood (James, you can put that on your 2o12 prediction list…)
3. Density of the bean. It does also make sense that beans with denser cellular structures would hold up better than those that are less dense. When we talk about coffee aging I think that we are talking about volatile organic materials that are degrading over time and disappearing into the atmosphere. After some passage of time there will be nearly nothing left but cellulose, which tastes starchy and bland. Again, based on anecdotal experience I’ve found beans that are especially dense do seem to hold their character a bit longer. But this correlation is significantly weaker than the one regarding moisture content.
4. The change in moisture/temperature that the coffee endures between the time it is dried on the tables or patios at origin and the time of arrival at the roastery. This definitely relates to water activity. When coffees go from places with high humidity (say, Caranavi Bolivia) to places with low humidity (how about La Paz?) and then back to an area with extremely high humidity (Arequipe, Chile) the beans are shedding and then re-absorbing moisture. Sometimes this can happen over and over again before the coffee actually reaches its final destination. And of course the speed of that process is affected by temperature, where high temperatures actually exacerbate the problem. If you imagine this taking place you can see how it might wreak some havoc within the coffee seeds and probably weaken the cellular structure, making it more prone to further oxygen-related quality loss down the road. So you can probably figure that coffees that undergo fewer changes in environment during storage/transit will probably hold up better that those that are exposed to extreme changes. (That’s a good reason, by the way, to dry mill coffee at altitude rather than down in the cities. For example, having coffee going from a farm in Marcala, Honduras to San Pedro Sula and its high-humidity, scorching hot climate for milling is not preferable…whereas milling coffee in Addis Ababa seems pretty OK, because the city is at altitude and it never gets too hot, too cold, or too wet.
5. Drying. I think that coffee which is dried too quickly (say, in 4 days under direct sunlight) will tend to show signs of aging sooner than coffee which is dried slowly (8 days under partial cover). Coffee that gets too hot (this happens oftentimes in wood-fired mechanical driers that don’t have good enough temperature control. It also happens sometimes in places where the direct sunlight during the middle of the day heats up the coffee too much, especially when it isn’t being turned regularly) will probably age faster than coffee that was dried uniformly and at a steady pace.

When you start thinking about all of these 5 things you realize that they are interrelated, and focusing on only one of them will probably not yield the correlations we want to see. Good research would track all of these factors to best determine what is going on….