A recent press release that came my way along with an offer for a review sample of a new coffee storage container has me wondering. The product's website states that there are four things that degrade the taste of coffee: Air, light, moisture, and CO2

They make some fairly amazing claims (quoted text directly from their website):
- the filter assembly in the lid "vents away flavor destroying CO2 gas."
- "This one-way valve removes the trapped gas that breaks down and destroys coffee flavor over time."
- "Without a freshness valve coffee can not be kept fresh."
There are more gems, but these are notable highlights.

I have read that we react with a negative sensation to CO2, presumably as a defense/survival mechanism. But the only thing I have read concerning CO2 is that its release displaces oxygen, but never anything about its presence destroying flavor. I was an art major, but isn't CO2 fairly inert? Would it not be mostly released by simply opening the container or grinding the beans? Don't the vast majority of coffee drinkers get their coffee at a post-roast age that CO2 volumes are negligible, if it exists at all?

I have written the advertising agency which sent out the offer with my questions on the above, and they replied, "Wow, you certainly know a lot about coffee." I have written the product website's customer service requesting some data on CO2's effect on coffee that backs up their claims, but still await an answer.

Beyond the other obvious flaws in the description of the value of their product, and not wanting to even name the product here (if you need to know, PM me and I will tell you, but please do not even mention it here as that is not my intent. I am asking if you have any information on the presence of CO2 in a storage container being detrimental to flavor.

I ask because I got most of the way through a chapter for my website concerning this product and before I post it and make an ass out of myself (again) I thought I would ask first..

Sorry, don't know a lot about CO2 and staling of coffee, but

Randy G. wrote: I have read that we react with a negative sensation to CO2, presumably as a defense/survival mechanism.

This is true - that is, when you hold your breath, the sensation of needing to take another breath is not caused by the lack of oxygen. It is caused by the build up of CO2. This is why it is easy to asphyxiate in a non-oxygen environment - your lungs can't tell. You can breathe pure nitrogen and only get light headed before you pass out because you don't have the sensation to take a breath, but otherwise feel okay. But take a snoot full of CO2 (even mixed with oxygen) and your lungs will feel like they're gonna explode.

Randy,

I have to agree with you, I call bunk on CO2 being a flavor destroying gas. Espresso Coffee: The Science Of Quality By Andrea Illy, Rinantonio Viani calls carbon dioxide "the most important non-aromatic volatile found in fresh roasted coffee" but explains that the build-up of this gas can lead to storage problems, especially if the packaging bursts leading to the development of one-way valves. I wish I had this book instead of relying on the limited preview of Google Books because the section I was reading is continued on a page not present in the preview.

Many other sources talk about CO2 helping to prevent oxidation of the coffee and this Terroir Coffee article advises that "CO2 buildup SHOULD NOT be expelled, as CO2 is somewhat inert, and will keep the beans fresher longer, when compared to Air containing more oxygen." As for CO2 completely preventing oxidation, I've seen references to a Michael Sivitz study that states that at least 10% of oxygen remains even with CO2 expelling oxygen through a one-way valve which is probably why some people use nitrogen flushes, which is an inert gas, to displace oxygen surrounding the coffee.

I feel that if you expel all the CO2, you also expel a lot of the volatile aromas and that CO2 plays an important part in the crema of espresso.

I've not read any source that even remotely suggests that CO2 in the atmosphere surrounding the beans destroys flavor (and I do have the Illy book ).

Just to be clear, Terroir's recommendation about not expelling CO2 applies to after you open the bag.

It's really a different subject, but CO2 can play a role in flavor. If the beans aren't allowed time after roast to outgas, CO2 that forms during roasting will be released during brewing and will interfere with extraction. That's why coffee brewed too soon after roast may taste underextracted (i.e., sour.) But we're talking about CO2 in the beans, not in the bag.

Thank you, folks,

The claims they made were such that I began to question my coffee sanity. I suppose their claims are not that surprising. They even garnered the "Most Innovative New Product Award" at Coffee Fest Seattle. Does that speak of the fest or just the lack of attendance by other companies - I think the color changing straws were more impressive than a jar with a valve. And if this qualifies as "innovative" then Joe's "Brazen" should win a Pulitzer.

While awaiting some responses here I also did some additional research so that sources can be quoted. I should have the article up on my site in two or three days, and when available I will post the link here.

And just to be clear, I did not want to mention the products name because I do not feel they deserve any more ranking assistance on Google than is absolutely necessary.

If a valve in a jar is now innovative, we need Dr. Who because the human race is on the brink!

MAY 26 - UPDATE - After nearly three weeks of research and writing, and numerous attempts to get the facts from the company, I have written a "review of the Friis Coffee Vault" and added it to my website. I never tested the product because I found their claims unfounded and unsupported by any facts, and they failed to respond to numerous requests for evidence or test results to support their claims. While they report that they earned the "Most Innovative New Product Award" at the Seattle Coffee Fest, I can't fathom how a sealed-lid canister with a one way valve could do so. Was there so little at Coffee Fest that this is the best they could do?

I contemplated posting this in the "The craziest %#*$ing thing I've seen all day..." thread, but will let it rest here instead. Their claims are just too %#*$ing crazy for that thread..

I came on this thread late. Your excellent quotes show the claims are bunk in the light of current coffee science. One note: it is true that nitrogen is a little better than CO2 as a coffee storage gas. The large Italian companies let the beans outgas for three days after roasting, then pack in nitrogen. This may be extend the shelf life from one month (for fresh roast valve bagged in CO2) to about two months. Pods are ground, degassed and nitrogen packed. But unless Friis is offering a nitrogen flushing system along witht he containers, that hardly means anything for them.

As usual Sivetz had it right -- all these technologies stops the beans from oxidizing, but the still lose their aromatics, and that's what makes the really great coffees really great

Thank you, Jim. That means a lot to me. I worked hard on this one to avoid the sort of historical situation I once created where a dead horse was beaten unmercifully and unnecessarily.

If anyone here has one of these items on hand and has the patent numbers handy, please forward them to me by PM or E-mail as I would like to read the patent.

I have also contacted David Heilbrunn, President of Coffee Fest, requesting information as to how the Friis won "Best New Innovative Product" at one of their shows.

I've got a container that I got at WalMart that is made of hard plastic, but it has the silicon gasket on the lid and it closes just like the one you've shown it just doesn't have the one way valve. I holds a pound of coffee and I haven't had any problems with the coffee going stale but then I don't let it set very long. I usually go through a pound in a little over a week, two at the most. But it being a clear plastic I keep it in the cabinet out of direct light.

I participated (in a minor way) in a recent thread on best practices for storing roasted coffee in an industry group on Linked-in. Several coffee scientists and professional roasters weighed in. There was disagreement about several methods (especially freezing), but a consensus that the blanket of CO2 that envelops the beans in a bag of degassing coffee is a good thing. It makes no sense for consumers to intentionally remove it at home.