I mentioned this idea to Jim Schulman in one of our regular emails recently, and perhaps others will consider it interesting enough to comment upon.
I can't speak to anyone else's experience with fresh coffee used for espresso, however my own experience with carefully home roasted high end Single Origins shows a very obvious pattern. My coffees tend to really "shine" during a relatively short period, which on average would be, counted from the roast date, from days 3-4 to days 7 or 8. Various factors could effect when this period of peak freshness occurs in the "degassing cycle," but I doubt very many coffees have a peak time period of more than 3-4 days in total.
It isn't that the coffee really and truly sucks just before and after that, rather it is that there is a period when my espresso's are at their best, and a period of time before or after that when they are "ok" but seldom spectacular. Perhaps other types of coffees (blends) dosed differently (I use around 14g per double shot) produce different results and a longer period of peak freshness, but I have my doubts and think that any quality coffee probably behaves more or less like this.
Being a home roaster, I have more control over this time and usage period than many. Like most here, I generally don't start using freshly roasted coffee for espresso until it has degassed somewhat; seldom do I start using a just-roasted coffee until it has degassed for 3 or 4 days. That part is the easy part. Generally some of what I roast will not get consumed until as much as 10-12 days after roasting, although generally the older the coffee the more likely it is to go into a milk drink.
As a proponent of freezing, I freeze quite a bit of coffee in a cold freezer, immediately after roasting.
Up until now, I've used freezing "passively," e.g. in a way that reduces the frequency of my roast sessions, and to deal with situations where I have more freshly roasted coffee than can be consumed before it goes stale. But what about another approach, the intentional use of freezing to enhance espresso quality?
My experience, both through blind taste testing and through normal use is that freezing preserves the fine qualities of fresh coffee, at least when done immediately after roasting, using a very cold freezer (others here can comment on their experiences with partially degassed coffee, such as what they get through mail order, or a less cold freezer such as one attached to a refrigerator).
So here's the question: Wouldn't it make more sense in regular use, for those who don't either buy or roast coffee extremely often, to only leave out enough coffee at one time that it can all be consumed within this 3-4 day "peak" time window, and to rely on the freezer, on a regular basis, defrosting only what can be consumed, each time, within a similarly short time window?
For me, this would mean freezing a greater percentage of what I produce in a roast session, and drinking a lot higher percentage of previously frozen coffee than is my normal practice. For others, this could mean putting more of their mail order or other commercially purchased coffees into the freezer on receipt, and consuming less when it is "fresh" and not previously frozen. I have not observed a shortening of the "peak" period in previously frozen coffee, but even if you thought that this was the case, you could just adjust the approach by reducing the quantity size of frozen coffee that you take out of the freezer at any one time.
Does this make sense as an overall strategy for maximizing espresso quality in a home environment?