# Roast dates from expiry dates



## tobyjrn6 (Dec 22, 2016)

I had a little search but couldnt find anything conclusive. It was my assumption that supermarket beans were given a 1 year best before period.

I've sadly been forced to pick up some waitrose beans until i have time to visit clifton coffee again. Judging by the combo of 1 way valve and expanded bag id say these beans degassed pretty recently. Combine that with the july 2019 BB, could these have been roasted in the last couple of weeks
















NB// im not expecting anything great but a reasonably fresh '3 strength' (which im guessing translates to a not-quite-as-charred roast) african coffee might just tide me over


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## DavecUK (Aug 6, 2013)

Not necessarily. They could have been roasted and bulk bagged, sent to a specific packer, decanted and repackaged for Waitrose. Equally the roaster could be roasting in massive quantities, leaving then in open bins for days while they get packed. Coffee doesn't degass, if formes CO2 due to an action with Oxygen, that formation of CO2 is limited by the amount of Oxygen available and the rate is temperature dependent (every 10C rise doubles the rate). They could have been roasted weeks or months ago.

Here is a little fun bag for you....these were roasted almost 4 weeks ago and the weather has been hot. They are Kraft paper, foil lined heat sealable bags. I don't use valves any more, because they are never truly 1 way and the thing they do is let flavour out and more oxygen in. This little funbag, is well puffed up after 4 weeks, but it hasn't popped yet. My experimentation has shown that these bags can just hold 300g, and with as much air as possible squeezed out, not pop before they need to be drunk. I have had some tested for almost 3 months and they were OK. if I use a valve bag I can keep on squeezing air out totalling with many times more volume than this little bag holds....My conclusion is the valves keep letting Oxygen back in to form more CO2 (accompanied by more staling). My other bags use the highest quality Wico valves you can get and they still let something back in. It's possible, but unlikely that those waitrose bags use Wico quality valves.

Now sure a bag might eventually pop (dunno), but my roast sharers should take that as a sign that they waited far too bloody long to drink it. I have one overriding interest and that is quality. I am lucky I can do this as commercial roasters don't really want to ship little potential exploders like this funbag. Imagine the fun DPD would have jumping on these. I should add it took about 10 days for them to get big, and they have not really expanded any more for the last couple of weeks. I had a shopping basket full at one point and was wondering if there would be a loud bang on one of those really hot nights


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## tobyjrn6 (Dec 22, 2016)

All of that makes perfect sad sense haha. Interesting experiments too.

To be fair it never fails to amaze me how little care they may or may not take when bulk processing things like this so it probably was a bit too good to be true. I'll report back on how flat and stale they end up tasting


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## DavecUK (Aug 6, 2013)

tobyjrn6 said:


> All of that makes perfect sad sense haha. Interesting experiments too.
> 
> To be fair it never fails to amaze me how little care they may or may not take when bulk processing things like this so it probably was a bit too good to be true. I'll report back on how flat and stale they end up tasting


you never know, you might have hit lucky and got a really fresh batch? However there is a certain reliability about using recommended roasters on here and in general you are helping small businesses who pay their taxes and support the economy. I would stress that I actually see Waitrose as one of the good guys, who do pay their taxes, but the small artisan guys really benefit from the support.

P.S. If one does actually pop...then I'm gonna quickly pinhole and sellotape the others


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## Dumnorix (Dec 29, 2017)

When I was last in Waitrose I found Union beans and Roastworks- I went for the latter as the roast date was only two weeks previous. They tasted pretty good.


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## tobyjrn6 (Dec 22, 2016)

DavecUK said:


> you never know, you might have hit lucky and got a really fresh batch? However there is a certain reliability about using recommended roasters on here and in general you are helping small businesses who pay their taxes and support the economy. I would stress that I actually see Waitrose as one of the good guys, who do pay their taxes, but the small artisan guys really benefit from the support.
> 
> P.S. If one does actually pop...then I'm gonna quickly pinhole and sellotape the others


Yeah I totally agree, as I said I just dont have time to go drive out to avonmouth for clifton while im revising and im running very low on my last bag from rave so it's very much a 'tide me over' kind of situation


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## slamm (Nov 26, 2016)

DavecUK said:


> Coffee doesn't degass, if formes CO2 due to an action with Oxygen, that formation of CO2 is limited by the amount of Oxygen available and the rate is temperature dependent (every 10C rise doubles the rate).


I normally give beans around 7 days rest so at this time of year if you get several days of high indoor temps do you find they are ready earlier?


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## DavecUK (Aug 6, 2013)

slamm said:


> I normally give beans around 7 days rest so at this time of year if you get several days of high indoor temps do you find they are ready earlier?


Yes, because (as a rule of thumb) biochemical reaction rates double for each 10C rise in temp....so at 30C, the coffee could well be drinkable after 3 or 4 days. If of course you believe as I do that the "degassing" process is not "degassing", but CO2 formation as a reaction with Oxygen and that other reactions go on as well which develop flavour and aroma in coffee (not necessarily totally oxygen related, although oxidation may form compounds that then later react with other compounds in roasted coffee).

Of course it might not mean that their flavour is as good as a slower development in a cooler environment, or that they remain at a peak for the same length of time....that I don't know and have usually yummed up a bag before I can find out.


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## Hasi (Dec 27, 2017)

I'm using a very similar technique as @DavecUK to store my roasts, putting them away in a wooden crate in our dark and cool basement.

Lately, I found the crate had been shatterd by the force of expanding bags. The latter were lying around bloated as if nothing ever happened...







Thus, my conclusion: both fresh beans and bags got to be pretty darn strong









As for OP question: depends on company, co-packing, and their likes. Some go as far as 2 years shelf life from roasted date, 1 or 1.5 years are quite common approximations. That being said, folk selling that type of roasts usually don't give a fork about one or two weeks, really. Some wouldn't even know coffee stales that quickly: common knowledge in the industry appears to be "it's just fine until it expires". Speaking from experience









I believe regulations have it that you'd get an identifier in form of a batch no. Some are coded well so you wouldn't be able to read out yourself. However, ringing their customer service line may shed some light onto your question - if it's worth the hassle


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## DavecUK (Aug 6, 2013)

Hasi said:


> I'm using a very similar technique as @DavecUK to store my roasts, putting them away in a wooden crate in our dark and cool basement.
> 
> Lately, I found the crate had been shatterd by the force of expanding bags. The latter were lying around bloated as if nothing ever happened...
> 
> ...


remember though, the forces on all the bags combined may not be as high as you think....just the low pressure of exhaust gases could do this!


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## tobyjrn6 (Dec 22, 2016)

Incidentally i pulled the first shot this morn and whilst the beans have clearly been burnt to a crisp, it was exponentially better than the comparison shot i paid £2 for from nero yesterday


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