Keeping Beans Fresh

[Vinitasse]

Silly question, but how much air do you leave in them to start with? If there's any/much air in them, then



I also contend that, although CO2 is a by-product of the roasting process, there is no 10L CO2/kg roasted coffee released. Rather, I suggest that sealing the bags without using a vacuum results in trapped oxygen that reacts with carbon compounds within the beans producing CO2 gas. Ie 1kg of roasted coffee may produce 10L of CO2 gas if exposed to oxygen, but this amount of CO2 is not within the beans.
There is a theory that vacuum packing is not really necessary as if 10L of CO2 is produced, a kilogram of coffee packed right after roasting will push out most, if not all, oxygen through the de-gassing valve. This presumes that there is indeed 10L of CO2 hiding within the cells of the coffee. If it is in fact the oxidisation of carbon compounds that produces the majority of the CO2, then one is better of using a vacuum packer to remove as much of the air as possible without damaging the beans. The bags I’ve packed with a vacuum packer only puff up if the valve is faulty. Bags without valves puff up a little.

Is still a feasible theory

An interesting comment following the cited article above reads as follows:

"It seems there is a disconnect here in what people mean by “releasing x litres of CO2″. I’m assuming that’s litres of CO2 at standard temperature and pressure. If the reaction causing the release of CO2 is a normal reversible reaction, then as the bag pressurizes it will slow down and eventually stop producing CO2. So, assuming the bag is strong enough, the amount of CO2 produced will be precisely enough to generate equilibrium pressure in the volume provided.
Put the coffee in a small, strong container and a large, strong container twice the size and you’ll find that one produces twice the amount of CO2 according to the ideal gas law.
Stating that coffee produces some specific amount of CO2 in a pressurized environment is impossible without stating the equilibrium pressure of the reaction and the volume of the container."


In any event, do as you wish. Store your coffee in the freezer, in vacuum bags, in glass jars or whatever. However, as a commercial roaster who manages to roast coffees that de-gas a huge amount of CO2, I will happily stick to bags with one-way valves and, hopefully, none of my coffees will ever see the inside of a freezer.

[Barry O'Speedwagon]

Silly question, but how much air do you leave in them to start with? If there's any/much air in them, then

Not a silly question. I leave as little air in the bags as is possible without using mechanical means (i.e. the bag is quite full, and I 'squeeze' it to limit the amount of air inside the bag upon initial sealing).

[chokkidog]

I've had that article for a while, from when this thread was quite active.......... it (the article) sort of died in the A, so to speak,

it's unfortunate that there hasn't been more followup. Hypothesis based on observation needs a lot of time and work to be correlated.....

otherwise it's purely conjecture. It would be good to know how his experiment with 60,000 bags is going!

If you read the whole lot he also says this;......

"The style of coffee that I’m familiar with is low to medium roast, high quality greens and vacuum packed in good quality trilaminate bags. What I say relates to this style of coffee only."

"Also we roast our coffee to much lower levels than most – I haven’t tested the effect of roast level on outgassing, but darker roasts are supposed to give out more CO2."

"For quality’s sake I reckon you’re best to roast a little often. However, xxxx is on the right track, freezing is your best option if you want to extend shelf life. ...... I recommend storing the beans in air-tight, single portion packs and defrosting fully in the pack before grinding. I wouldn’t do this commercially, rather it’s my recommendation for customers who want to extend the shelf life at home."

"Many of the bags do expand to resemble balloons. None have exploded. I’ve had a couple that have stretched to the point that they’ve breached the seam and deflated.
I’m still monitoring the experiment and don’t want to preempt the conclusions. However, as you asked, it seems to depend on roast level: the darker the roast the greater the expansion. Briefly, the taste of the coffee is consistently good. The coffee seems to last longer, but this needs further testing."

All these statements could do with some discussion.

Illy's book was written quite a while ago.... I would love a good, reputable lab to do some honest work on the topic.

What does 10L of CO2 actually look like? ( yeah , I know...... nuthin'; cos it's invisible.. :-D) And given that CO2 varies at different roast levels,

Illy's statement requires some scrutiny.

Having said all that, people ( not referring to the writer of the article) who just say "I believe xxxxxx" and can't back it up with any evidence, are
only followers of an idea.

[DesigningByCoffee]

I use both valved and non-valved bags. Don't find much difference either way in flavour - but I also home roast so struggle to store anything longer than a week!
But I do find that the bags don't inflate much after being first roasted/sealed - but once 'cracked' whether day 1 or day 7 - the next few days they blow up a fair bit? So could it be part of the oxidation process rather than a de-gas?
Just a thought

[Dragunov21]

Silly question, but how much air do you leave in them to start with? If there's any/much air in them, then

I also contend that, although CO2 is a by-product of the roasting process, there is no 10L CO2/kg roasted coffee released. Rather, I suggest that sealing the bags without using a vacuum results in trapped oxygen that reacts with carbon compounds within the beans producing CO2 gas. Ie 1kg of roasted coffee may produce 10L of CO2 gas if exposed to oxygen, but this amount of CO2 is not within the beans.
There is a theory that vacuum packing is not really necessary as if 10L of CO2 is produced, a kilogram of coffee packed right after roasting will push out most, if not all, oxygen through the de-gassing valve. This presumes that there is indeed 10L of CO2 hiding within the cells of the coffee. If it is in fact the oxidisation of carbon compounds that produces the majority of the CO2, then one is better of using a vacuum packer to remove as much of the air as possible without damaging the beans. The bags I’ve packed with a vacuum packer only puff up if the valve is faulty. Bags without valves puff up a little.

Is still a feasible theory

[Barry O'Speedwagon]

Well, I store my roasted beans in the 250g one-way valve bags, and without a shadow of a doubt the bags increase in volume between days 1 and 4. Obviously the materials out of which your bags are made will affect the extent to which any expansion due to de-gassing remains noticeable.

[Dragunov21]

I about the embark on the home roasting journey, and was wondering how pro roasters here store their roasted beans prior to & during use?

I've read about all sorts of bags with one-way valves & vacuum containers, but some insist that just putting it into an airtight container is good enough or even better.

Why I stopped packaging our coffee in one-way valves | agoodkeensavage

I've actually wondered about this, as I've stored home-roasted beans in ziplock bags with the air sucked out of them (so, sealed) and... they don't visibly reinflate. At all.

Excellent article, cheers.

[Yelta]

I about the embark on the home roasting journey, and was wondering how pro roasters here store their roasted beans prior to & during use?

I've read about all sorts of bags with one-way valves & vacuum containers, but some insist that just putting it into an airtight container is good enough or even better.

Why I stopped packaging our coffee in one-way valves | agoodkeensavage

So, heres a statement to get the drums beating again.

Good pick up jh001


"Why I stopped packaging our coffee in one-way valves

Yesterday I decided to do away with one-way valves on our roasted coffee bags when packing with a vacuum. It’s been something that I’ve been testing for many years now and time again I’ve come to the conclusion that they really don’t make that much difference to the coffee. Indeed, too often they provide an access point for oxygen to enter the bag and degrade the coffee."

[jh001]

How do you store your roasted beans?

I about the embark on the home roasting journey, and was wondering how pro roasters here store their roasted beans prior to & during use?

I've read about all sorts of bags with one-way valves & vacuum containers, but some insist that just putting it into an airtight container is good enough or even better.

Why I stopped packaging our coffee in one-way valves | agoodkeensavage

[Bosco_Lever]

The point everyone seems to miss is that Temperatures do vary around Australia. If you live in Tasmania, storing your beans in a cool dry place is easy.The same does not apply if you live in the Tropics. A temperature controlled environment may be difficult to find, hence why beans are sometimes kept in a fridge. Heat will adversely affect roasted coffee, and a few hours in a 40C+ environment will deteriorate the flavour.
If in doubt, talk to your roaster, they should be able to advise you.

I would not send beans via post during very hot weather, better to wait for it to cool down.

[Yelta]

I suspect some of the newer members would do well to have a read through this thread before posting, as Mal said early on the subject has been done to death.

Only reason for my update re fridge was my earlier statement "no beans of mine will ever see the inside of a fridge" surprised no one picked me up on it.

Keep em in a smelly sock if it works for ya.

[Juvv]

I use a "jam jar" with a plastic lid. works perfectly. i dont store for more than probably a week though cause i drink it all

[cdhjrf]

I've tried vacuum containers, fridge and freezer and nothing seems to work better than storing the beans in the original bag that they came in a cool dry place.

Craig

[Quarimor]

Storing coffee beans in a fridge/freezer never seemed to work out for me. If anything it seemed to make it worse. Getting a bean vacuum helps to extend the shelf-life a little bit, but even then there's only so long they will stay fresh.

[Yelta]

Typo guy's, should have read (As a matter of interest none of my roasted beans will ever see the inside of a fridge or freezer.) by the time I picked it up too late to edit.

As an update.

Some of you are aware that I've been away for a little over a month, a few days before leaving I roasted a batch of 750 grams, broke into it the day prior to departure, it was providing nice shots, plenty of flavour and lots of crema, so what to do with the remaining 600 grams while I was away?

Divided the batch in two, half into a one way valve bag and the rest into a sealed jar and put them both into the fridge (not the freezer) on my return took them both out and allowed the to come up to room temp before opening, after about 6 or 8 hrs pulled my first shots, the result, while better than no coffee at all both batches had deteriorated significantly, seems being in the fridge had not stopped the aging process, and I suspect may well have contributed to it, still plenty of crema but the shots are flat tasting, verging on sour.

An interesting point, when opened both batches of fridge stored beans were showing no signs of oiliness, however within a few hours they both had an oily sheen.

Seems to me it matters little whether you store them in the fridge or on a shelf, over the course of a month they will degrade.