Posted Wed Jan 26, 2011, 7:59am Subject: Re: Post Roast Coffee Bean Care
Agreed, Starbucks can be months old. I was going by an acquaintance who said they used to work at one of the SBUX roaster plants. The "use by" date is typically 5-10 months ahead of the roast/blend/packaging date. He said they bag the beans in a low O2/mostly nitrogen environment, seal them in 1-way valve and apply a mild vacuum. Natural off-gassing happens, so that's the function of the 1-way valve. I've never seen the operation, so I'm just passing on what I was told.
I had about 5 samples of vacuum packed (foodsaver) samples I roasted on 1/8/11, packed about 3 days post roast (so must have been 1/13/11 when I vacu-saved them), in the freezer. Opened one up y'day - very excellent aroma and not at all what I would consider stale when brewed. That leaves 4 samples. Off-gassing must have completed because the full vacuum was still preserved.
I don't have any one-way valve sealable coffee bags around any more, have to go shopping, I guess. I see that Ziploc has a vacuum freezer bag, but their freezer bags tend to still have a coffee aroma even when sealed, which tells me they may not be as nice a seal as a Foodsaver. Downside of the Foodsaver, of course, is the 1-time use (lack of resealability - easily resealed, anyways).
@ yakster, it's mostly curiosity that got me thinking. I've definitely had good bags of pre-roasted beans, and stale bags of pre-roasted beans.
I was also interested because I have another friend that worked at NASA on their long-term food storage research, not surprisingly, GOOD coffee was one of the foods they definitely want on a long-term space voyage (say to Mars, or bulk long-term storage for a Moonbase). The question is how best to get coffee that may be several years old in a package that makes sense and decently consumable for the spacevoyager.
We know long term storage of green beans is possible, but maybe not practical for taking with you and roasting in space, Keurig and Flavia both seem to have passable coffee that is pre-roasted AND pre-ground AND prepackaged, and some of the research is actually rumored to have been part of the Starbucks Via program (microground coffee that prepares like instant, both appealing for low mass and low packaging volume if vacu-packed). RUMOR, meaning probably not true, but interesting anyway that Starbucks isn't the ONLY one that thought of microground semi-instant packet contact brewed coffee.
Their enemies are: 1) microorganisms (fungi, bacteria), 2) oxygen, and 3) anerobic reactions. Complex foods that have proteins, combinations of starch and sugars, a cellular structure and too acidic or basic, and high amounts of water are especially difficult. Meat with green veggies, and anything with citrus is especially difficult - you can get all the oxygen out, all of the microorgs killed, and it STILL undergoes chemical reactions that change the basic chemistry of the food you're trying to preserve.
However, there are indications that roasted coffee and even ground coffee has very high potential for multi-year storage and passable consumability. Fungi is still a potential, but the roasting process kills most microorgs (called thermostabilization) and has a side benefit of removing much of the water (which may play a part in anerobic reactions). If you keep the coffee reasonably sterile and dry post-roast, then you have to deal with the period of chemical stabilization post-roast (off gassing CO2) which messes with volumetric storage efficiency, and if you do manage to pack it without oxygen you still have room temperature (very slow) reactions going on. This isn't just coffee - it's all foods. Since these reactions depend on energy to happen, the solution to this is freezing it - lowering the reaction temperature and slowing down chem reactions - hopefully without much water present to break down structure for things that have cells (like coffee beans or worse, meats and fruits). Breaking down the cell walls of a piece of food with ice crystals allows leakage and interaction of previously-separated enzymes and proteins.
So, short story long, that's why I started to get interested in long-term coffee storage. I thought it'd be nice to have fresh reference samples for taste as I build a library of roasts and beans (what DID that Ethiopia City+ I roasted 8 months ago taste like again? Is it different this season or just my imagination), ability to send coffee to less-savvy coffee consumers and still get them to have a "good cup o' joe" experience that is superior to open-air pots in the office, that sort of thing.
That, and I like to challenge conventional wisdom statements, and test them. I've tried 20g/4 oz water brews (yuck!), low temp brewing (much below 170ºF - try it or trust me, don't bother - the contact time would have to be in the tens of minutes), 5g/8oz brew (yikes) - so I'm fairly safe in saying that, for me, 10g/6oz +/- a gram or two and brewing temp above 180º to just off boil is a very good ratio of coffee to water and temperature (provided you get the grind right for your brew method contact time). There's probably a reason they use that ratio for professional cupping... LOL
I know coffee CAN be made to be basically indistinguishable past 2 weeks (oxygen free low temperature) from 4-day post roast coffee. I don't think I could have picked the difference between frozen V-packed and a similar 4-day old roast stored in a ziplock inside a sealed cannister (roasted 1/22/11). (Caviat - I'm not a professional cupper, I'm just an engineer with a low cost hi value hobby!). The 1/8/11 roast was actually better because I didn't do as good a job on the 1/22/11 roast, but that's part of the difficulty - getting identical fresh samples and trying to do blind taste tests is not easy! LOL
Keurig and Flavia, Starbucks (whole roasted beans, ground, and via), etc., they all get away with long term roasted coffee with passable drinkability - I was wondering if it is possible to have TRUE stabilized taste and what the limits really are for roasted coffee - for me, I think I have indications they are possibly well past 2 weeks - but this also means that different methods must have different taste decay rates - so which method has the lowest taste decay, if storage in a non-sealed 1-way bag accessed once a day decays noticeably within 7 days post-roast? Like anything in the universe, one question leads to others which sometimes leads to a nugget of discovery.
Cheers!
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Posted Tue Feb 1, 2011, 10:00am Subject: Re: Post Roast Coffee Bean Care
Roasted a batch of Guatamala Huehuetenango. Predicted 1st Crack for 227g was 10.7 minutes into the roast, actual turned out to be approximately 10.1 minutes (10:08). This was based on a bean factor of -157, from user CeeZee's 150g sample. Ran on P1, and used door opening to control the temp at about 415º at the start of 1st Crack. 1st Crack lasted an abnormally long time, approximately 4 minutes, and end of 1st crack immediately rolled into 2nd crack. The roast turned out splendid anyway. I think I needed to hold the temp a bit longer PRE 1st crack and then roast it into 1st crack. I was a bit concerned I was baking the roast, but definitely not the case after tasting it the following day.
I obtained these new Ziploc Vacuum bags Click Here (www.ziploc.com) and took a 10g sample of the roast and ziploc vacuum packed the rest within 5 minutes of roasting, and put this in the cold section of my refrigerator. I intend to check/taste this after 1 month. Several days later and the beans have definitely off-gassed but nothing unmanageable (pack is loose but not distended or distressed in any way). This compared to some older beans which I was going to compost - but vacuum packed them for posterity in the Ziploc Vacbags - and they still maintained the vacuum (look like a foodsaver pack). Once sealed, there is absolutely no detectable coffee aroma (unlike "normal" ziploc freezer bags).
The valves are not 1-way valves, they require an external vacuum applied to open the valve - I tried to fill one with air and squeeze it to see if it would function like a 1-way and managed to burst it instead.
I intend to taste one of my longer term Foodsaver Vacpacked samples in the freezer about mid-February. I haven't done my full out storage study, as I am trying to think about what my controls should be. I have confirmed that if you leave a sample of coffee beans in a shallow bowl on the counter for 2 weeks, you have some pretty "flat" tasting coffee when you brew it. I think that's a good control for "stale" but that was never the issue - if stale is 0% and 36hours post roast is 100% flavor, I'm trying to find how long coffee can be stored and still be about 80-90% fresh - the level at which I should be able to repeatably detect the onset of deterioration.
In doing this study, I'm fairly sure I've determined to my satisfaction that it does take more than vacuum to preserve roasted coffee beans. Lack of Oxygen exposure is only part of the issue - you also need to store it in lower than ambient temps to go longer than a month or two to stall or slow down any anerobic reactions. The other problem with longer-term storage testing is the controls - same bean, same roast, only difference being age and storage method is not really even physically possible. Is what you taste due to staleness or just a bad roast? Is it REALLY degraded from freshly roasted, or just your imagination because it SHOULD be stale after 9 weeks in a freezer? Is your mind magnifying the differences? Might you have an overly optimistic taste memory (if you can't have a replicate roast to immediately compare)? How much degradation before you say "ugh, this is undrinkable"? If you roast 8 month old green beans - is that really "freshly" roasted? What does "stale" coffee taste like?
So, ideally it would be good to have properly "stale" samples - easy enough - and ALSO fresh samples. Maybe use a consistent bean that is easily roasted and replicated and shows good crop repeatability (Colombia?).
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
harmolodic Senior Member Joined: 8 Aug 2006 Posts: 122 Location: DC Expertise: I love coffee
Posted Tue Feb 1, 2011, 12:45pm Subject: Re: Post Roast Coffee Bean Care
I view coffee as a food--let's say a steak. Once it's cooked, a rapid and inevitable process of degradation begins. This process can be retarded but at a certain point--around two weeks, give or take a little--it reaches a point where a relatively trained palate can tell that it's life is over. You can freeze a cooked steak but it will never be fresh again.
The sad thing is that the coffee-drinking public at large has no clue that what they've been told for decades is fresh coffee, really isn't. They don't know they're drinking swill. Starbucks coffee sitting in a bag for ten months...sad. it's crap. But at least it's better than those large cans of pathetic robusta that were ground and packed 3 years before...so we're going in the right direction!
I've tried lots of different ways to prolong the life of my roasts but nothing does the trick. So I roast enough for a week or two, for family and co-workers, and use simple one-way valve bags. I never end up with coffee that's older than 12-14 days.
LOL. "Verbosius Maximus". Sounds like a fitting userid.
Len
"Coffee leads men to trifle away their time, scald their chops, and spend their money, all for a little base, black, thick, nasty, bitter, stinking nauseous puddle water." ~The Women's Petition Against Coffee, 1674
Posted Tue Feb 22, 2011, 2:25pm Subject: Re: Post Roast Coffee Bean Care
Finally got around to trying sample #2 of 5 roasted on 1/8/11, vacuum packed and freezer stored.
Previously, I had brewed (2 minute contact time, inverted Aeropress method) week old air exposed of the same bean (roasted later but to same parameters, 2C+15 seconds) - the bloom is basically nonexistent, the flavor looses much of the floral characteristics, and any "spice" hints (nutmeg, cinnamon, and cocoa/dark chocolate) are extremely distant or muted at best. The beans have some flecks of oil on them with air-exposed batch. I would consider these fairly "stale" - still better than pre-ground Folgers, but definitely nothing like an artisan coffee. If I rated Folgers as 0% and freshly roasted/rested at 100%, I'd have to say sitting in a bowl at room temp is a solid 20% flavor left. Repeating my assessment - fairly stale.
I'm contrasting this with my consistent memory of how this coffee is supposed to taste (roasted and brewed several pounds of it now).
So, with that in mind, I thawed the VPF sample for ~16 hours in cupboard prior to opening.
Aroma of the beans upon opening the pack is (to me) indistinguishable from freshly roasted +3 day rest in ziploc at room temperature. No oil flecks on the bean. The bean is an Indian Giri-Estates, a portion of a 5 lb green bean batch I have been using to train on consistency for roasting, and batch after batch comes out within seconds of predicted 1st crack.
I then brewed the vac-packed sample.
Bloom is basically indistinguishable from freshly roasted/rested. Lots of it. Aroma seems nice and full. In the cup, I'd be very hard pressed to choose it different from freshly roasted. My 'fridge ain't anything special, Kitchen Aid with a bottom freezer that is frost free (and so cycles low temp). Flavor profile is basically the same as I remember, same characteristics, same body - if you TOLD me it was stored for extended period and frozen, I'd maybe be arm-twisted to call it 95% of full flavor - but I would have to sample it back to back (which I wasn't able to do) to say conclusively if there was any noticeable degradation. Even then, I'd be questioning whether the difference was subtle roasting differences, or some other variable.
That's roasted, 3 days rest in sealed bag, vacuum packed and freezer stored, then thawed/ground/brewed over six weeks post roasting.
I keep eyeing the bag of Guatemala HueHuetenango in the refrigerator. It's been a month (roasted on 1/17/11 and immediately sealed in the ziploc vacuum freezer bag) but I want to roast the other half of the Guatemala, rest it for 3 days in sealed container (probably a ziploc vacuum freezer bag), then break open both and brew two cups back to back. It may be over 6 weeks until I get to it (having fun with Tanzania Mbinga and surprisingly good El Salvador Siberia right now).
I'm fairly convinced that 6weeks + (for me) of post-roast storage is easily achievable with excellent (but limited) results and minimal flavor degradation. I actually don't believe that 1-way valve bags at room temperature do the trick - but have not absolutely ruled them out. To me, they just don't seem to have the sealing capability needed.
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Posted Fri Feb 25, 2011, 4:16pm Subject: Re: Post Roast Coffee Bean Care
Netphilosopher Said:
I'm fairly convinced that 6weeks + (for me) of post-roast storage is easily achievable with excellent (but limited) results and minimal flavor degradation. I actually don't believe that 1-way valve bags at room temperature do the trick - but have not absolutely ruled them out. To me, they just don't seem to have the sealing capability needed.
Rest assured - You CAN absolutely rule out "1-way valve bags at room temperature". After seven days of sitting in a 1-way valve bag at room temperature, the beans start losing flavor.
Life is too short to drink bad wine (or bad coffee)
Posted Mon Mar 7, 2011, 12:37pm Subject: Re: Post Roast Coffee Bean Care
rgrosz Said:
Rest assured - You CAN absolutely rule out "1-way valve bags at room temperature". After seven days of sitting in a 1-way valve bag at room temperature, the beans start losing flavor.
You're right, I have now ruled out an opened unsealed 1-way valve bag at room temperature - it will begin losing noticeable flavor in about 10 days.
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Posted Thu Mar 10, 2011, 7:58am Subject: Re: Post Roast Coffee Bean Care
And I finally got to roast the 2nd half of the Guatemala. It came out perfect, as close as I could have hoped to my 1/29 roast of the first half - so, this weekend, I'll have a cup of the 1/29 roast (ziploc vacuum freezer stored in fridge) and this 3/9 roast back to back. That's 39 days different (5 1/2 weeks).
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
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