I had just assumed they were heat sealed. As mentioned you can see the bags physically and can be in a better position to comment. If they aren't sealed then presumably they are meant for economy, and are either (1) stale, or (2) always extremely freshly roasted and meant to be rebagged by the customer in their storage of preference upon purchase.

But also it's worth mentioning that these sort of arguments are mostly only critical for the home espresso maker, and that most other types of brewing people are going to see a marked increase over many other types of coffee. I'm sure this is mostly the intended market for people that pick up bags at a store. If you really want something that is fresh and roasted the same day so you can bag heat sealed and go straight to the freezer...you should be looking to make a visit to the roaster itself.

Just my opinions.

Macro roasters like Starbucks, whose business models depend upon maximizing shelf life, always employ valve bags. This strikes me as pretty good evidence that valve bags do indeed extend shelf life.

If micro roasters such as Barefoot forgo the valves, I think that in addition to trimming costs, it is a freshness play. In other words, "buy it fresh (and local) from us, and you won't need a valve".

Similarly, the fresh bread from my local bakery goes stale more quickly than the packaged stuff from Target. Could the local bakery use more sophisticated packaging, and maybe even preservatives to extend the life of the product? Sure. But they don't, because they want me to buy it fresh, consume it quickly, and come back to buy some more. It doesn't make sense for them to invest in preservation technologies.

portamento wrote:Valved bags do not prevent degassing. They simple retard oxidation.

The point is that as the coffee degases, oxygen in the bag is displaced by CO2. A valve bag ought to have a lower concentration of oxygen than a non-valve bag.

What I meant was not that the valves prevent degassing (obviously not - otherwise what would be the point of the valve), but that putting the coffee in bags immediately, as opposed to letting them sit for a day and then putting it in unvalved bags later, as Andre was thinking might be happening, might slow the process down comparatively. (In a bag = slower degassing than no bag.)

JimWright wrote:What I meant was not that the valves prevent degassing (obviously not - otherwise what would be the point of the valve), but that putting the coffee in bags immediately, as opposed to letting them sit for a day and then putting it in unvalved bags later, as Andre was thinking might be happening, might slow the process down comparatively. (In a bag = slower degassing than no bag.)

Yes, it is best for the roaster to put the coffee immediately into the valve bag. You want as much of the degassing as possible to take place inside the bag, to as to maximize the displacement of oxygen.

In the unvalved bag, I guess you are saying the higher air pressure in a puffed-out airtight bag might slow degassing. Not sure the pressure is high enough to make a difference.

When I ship roasted coffee I'll heat seal a zipper valve bag to avoid any chance of spilling. Fill, seal and ship right off. For direct local where it will be used quickly I'll just use a good quality lined tin tie bag at about 1/3 the price. I don't think it's possible to slow the off gassing. Once a valve bag is opened it loses most of purpose value. It only takes a small percentage of o2 to create oxidation.

portamento wrote:Yes, it is best for the roaster to put the coffee immediately into the valve bag. You want as much of the degassing as possible to take place inside the bag, to as to maximize the displacement of oxygen.

In the unvalved bag, I guess you are saying the higher air pressure in a puffed-out airtight bag might slow degassing. Not sure the pressure is high enough to make a difference.

Yeah, exactly. And if what you say is right - degassing coffee replaces the O2 with CO2, reducing oxidation, then switching to unvalved bags is suboptimal for coffee preservation. This seems like a strange move then, since Barefoot sells several well known and loved varieties of espresso consumed by H-B types as well as a lot of other great coffees. Looks like we may need to be more diligent about getting very fresh bags in the cafe then!

farmroast wrote:When I ship roasted coffee I'll heat seal a zipper valve bag to avoid any chance of spilling. Fill, seal and ship right off. For direct local where it will be used quickly I'll just use a good quality lined tin tie bag at about 1/3 the price. I don't think it's possible to slow the off gassing.

Hmmmm. Even if not, I think bagging immediately using the valved bags, as Ryan suggests, makes sense. (The best solution, of course, is substantial positive pressure using an inert gas, a la Illy, which should both reduce oxidation and maybe even slow degassing, but this is expensive packaging.) But yes, if you bag immediately into a tin tie bag this should be ok, as long as the coffee is bought and consumed immediately. The trick is that if the coffee is 10 days old already when you sell it, it may be getting stale by the time it's consumed if not already past its prime. (Esp. for espresso.) In the case where the coffee may need to be on the shelf for a week or more, seems to me like valved bags make sense. Of course, if folks have tested anything like this and found to the contrary, I'd be most curious to know!

Valve bags, gas flushed, vacuumed bricks were all created to try to extend shelf life but none really accomplish it. They won't smell too bad when first opened but then stale extremely fast once oxygen is introduced. I won't call it "fresh" after 6 days and goes into reduced price.

I can't really disagree much about the overall result Ed, nor about your own practices (kudos!), as I've certainly found a noticeable difference between 10 day old coffee and 2 day old, whether in valved or unvalved bags, and have been surprised by the willingness of some other premier roasters to leave beans I'd think of as past their prime on the shelf. I wonder, though, in any event, whether there might be material differences in how much extra life you get between the various methods even if we're only talking about a scale of a day or three - I'm particularly curious whether pressurized N2 canisters might get you some more time than bags (either valved or unvalved, or vacuum packed), and whether going from immediately packed valved bags to delayed-pack unvalved bags yields a noticeable acceleration of staling.

And returning to the original topic, I noticed that this bag of The Boss had some strong sweet berry notes that were totally gone by day 7 past the stamped roast date - I'm consuming coffee a bit more slowly now as my wife has had to stop consuming most caffeine and her taste for coffee is going off as well (hopefully temporarily), and it looks like I'm going to need to start freezing half bags now.

I like Vivace's half pound immediately-bagged-with-valves bags, more realistic for the average consumer, the bigger bags were never that much of a problem before but now with the wife going off the juice...