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Topic: Re-use Roasted Coffee Bags? (20 msgs / 462 lines)
1) From: David Morgenlender
I've been going through the 1/4 lb. clear roasted coffee bags (with 1-way=
 valve)
from SM extremely quickly.  But I haven't thrown the used ones away.  Has
anybody tried re-using the bags, perhaps after washing them out?  Are any
unwanted flavors or aromas introduced?
Dave
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Dave Morgenlender
e-mail: dmorgen
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2) From: Les
Dave,
I get 4-8 rounds out of each bag.  Wash with soapy water, rinse, and dry.
Les
On 10/3/06, David Morgenlender  wrote:
<Snip>

3) From: Aaron
as long as you wash them out thoroughly and dont leave any water in 
there to get stale (though some might get stuck up in the valve flapper 
thingie) they should be fine....
aaron

4) From: Dave Ehrenkranz
I have reused the bags without washing and haven't noticed anything 
dire.
dave
On Oct 3, 2006, at 3:08 PM, Aaron wrote:
<Snip>

5) From: Aaron
Dave, I have used them at times too without washing or rinsing, but if 
you happen to get a real oily roast, there is a chance some of the oils 
could be left behind and go rancid or alter the taste or impart a stale 
taste to the next batch put in there.  I have seen this with the screw 
cap plastic containers I use if I don't wash them.
aaron

6) From: David Matz
I reuse the bags multiple times.  I wash them depending on the coffee and
roast that was in it.  If I change the coffee that was in the bag or the
roast was oily it gets washed.  If the roast gets really oily (my Freshroast
occasionally gets a bit of chaff in the controls and the heater stays on)
that really dark roast goes in a glass canning jar rather than a bag.

7) From: raymanowen
The 1Qt Mason Wide Mouth fruit jars go through the dish washer easily
because of their weight. The quart size holds less than a pound roasted of
most beans, and in a week they pick up definite odors from the previous
occupants.
If you wanted to design a one-way valve for these jars, you could hardly do
better than the lids themselves. Internal pressure (CO2) can unseat the disc
and allow the gas to escape. External pressure (barometric pressure rise)
will tend to seat the disc and seal it, = diode.
Cheers -RayO, aka Opa!
-- 
"When the theme hits the bass, I dance the Jig!" - -Virgil Fox at the Mighty
Wichita (ex- NYC Paramount) WurliTzer- 1976

8) From: Sharon Allsup
Dave -
I use the 1/4 and 1/2-lb clear one-way-valve bags dozens of times
without any odors or mess or even bothering with washing them in
between.  But I cheat:  I put the beans in a small regular plastic
sandwich bag that's left open, and put that into the one-way-valve
bag.  Then when I need coffee I pull out the inner bag.  All the oils
-- and dust from the grounds -- end up in the inner bag.  The beans
never contact the outer bag.
It's crude, but it works beautifully for letting me have both the
one-way-valve benefits and not having to bother with messy cleanups
and bag drying and stuff.  Usually the only time I have to clean the
one-way-valve bag itself is when there's been an accident like the
cats knocking a full one off the shelf so the beans pour out of the
inner "liner" bag ... or the morning I wasn't awake and poured ground
coffee into the valve bag instead of back into the "liner" bag it came
from.
I'm also labeling the sandwich bags with the bean information, then
make sure the label shows through the clear plastic front of the
one-way-valve bag.
The typical el cheapo generic-store-brand sandwich-sized baggie or
ziplock holds about 1/3 pound of coffee comfortably.  1/2 pound is
pushing it.  Since I roast 1/4 pound at a time, it works perfectly.
The generic baggies are a penny or two each, and the quality doesn't
really matter since they're not being used for air-tightness or
keeping the beans fresh:  they're merely "inner liners" and convenient
ways of pulling great coffee out of the one-way-valve bag.
-Sharon

9) From: Eddie Dove
Great idea.
So the cats are into fresh roast too?
Eddie
On 10/3/06, Sharon Allsup  wrote:
<Snip>

10) From: Don Cummings
Thanks for writing this Ray.  I was beginning to think I was the only one
who understood that mason jar lids (the two piece ones) are basically large
versions of the little valves on valved bags.
They are designed to let gas escape and to keep potentially bacteria
contaminated air out.  And they do the job admirably.
I used to point this out whenever a thread about installing valves on mason
jars came up but now I just move on.
On 10/3/06, raymanowen  wrote:
<Snip>
-- 
Don

11) From: Justin Marquez
On 10/3/06, raymanowen  wrote:
<Snip>
- 1976
Ray -
But... when you screw down the ring the lid can't move up (or down for
that matter) .
If you don't snug down the ring then there is no seal at all, is
there? Otherwise, there would be no need for a ring.  (I know that
when you can stuff that the vacuum holds the lid on and no ring is
needed once the jar is cooled, but as CO2 is expected to evolve from
the roasted beans, I think the ring must stay snugged on to keep air
out.)
Safe Journeys and Sweet Music
Justin Marquez (CYPRESS, TX)

12) From: Eddie Dove
I don't understand ... if I screw the ring down, how does the gas escape?
Seriously, I am asking.
Eddie
On 10/3/06, Don Cummings  wrote:
<Snip>

13) From: Leo Zick
This is a multi-part message in MIME format.
i think if the rings are not sealed shut, they let air both in and out. they
cant act as one way valves.  
From: Eddie Dove [mailto:southcoastcoffeeroaster] 
Sent: Tuesday, October 03, 2006 10:34 PM
To: homeroast
Subject: Re: +Re-use Roasted Coffee Bags?
I don't understand ... if I screw the ring down, how does the gas escape?
Seriously, I am asking.
Eddie
On 10/3/06, Don Cummings <  
donrcummings> wrote: 
Thanks for writing this Ray.  I was beginning to think I was the only one
who understood that mason jar lids (the two piece ones) are basically large
versions of the little valves on valved bags.  
 
They are designed to let gas escape and to keep potentially bacteria
contaminated air out.  And they do the job admirably.
 
I used to point this out whenever a thread about installing valves on mason
jars came up but now I just move on. 
On 10/3/06, raymanowen < raymanowen
 > wrote: 
The 1Qt Mason Wide Mouth fruit jars go through the dish washer easily
because of their weight. The quart size holds less than a pound roasted of
most beans, and in a week they pick up definite odors from the previous
occupants. 
If you wanted to design a one-way valve for these jars, you could hardly do
better than the lids themselves. Internal pressure (CO2) can unseat the disc
and allow the gas to escape. External pressure (barometric pressure rise)
will tend to seat the disc and seal it, = diode. 
Cheers -RayO, aka Opa!
-- 
"When the theme hits the bass, I dance the Jig!" - -Virgil Fox at the Mighty
Wichita (ex- NYC Paramount) WurliTzer- 1976 
-- 
Don 

14) From: Don Cummings
When you can (things like fruit jelly for example) you leave the outer ring
loose while you heat the innards in a hot water bath.  The expansion of the
contents and subsequent release of gas can push past the loose inner ring.
After you remove them from the heat the expansion stops and the inner ring
forms its natural seal because of the design.
As a corollary when you put freshly roasted beans in the jar the CO2 escapes
by pushing the inner ring up (remember I said you leave the outer ring
slightly loose.)  The weight of the ring and outer atmospheric pressure will
not allow any substantive quantity of external air into the jar. As Justin
said, when canning the vacuum created keeps a good seal, but if you think
about it the vacuum would not be created in the first place if there was not
a good seal already between the jar and the inner ring. After a day or so of
degassing tighten the outer ring.
Trust me this system works better than the flimsy plastic 'one-way' valves
on the bags. They do not create a perfect seal.   If you doubt this take a
couple marshmallows and throw them in a valve bag and a canning jar.  Vacuum
both and see which allows more air in over a couple day period.
On 10/3/06, Justin Marquez  wrote:
<Snip>
-- 
Don

15) From: cja
So the easiest solution still seems to be to stick a one way valve on 
the lid (very easy), screw it down on day one and walk away. Besides, 
what fun is a jar if you can't tinker with it.
Chad
On Tue, 3 Oct 2006 10:23pm, Don Cummings wrote:
<Snip>

16) From: raymanowen
"...if I screw the ring down, how does the gas escape?"
Unscrew it, the same as you'd do to let some beans escape...
I think- unless the jars are tumbling around, the gasses would tend to
stratify in the jars. Especially if you just loosely cap them initially, the
CO2 will fill the jar and displace the O2 molecules out the top.
I just fill the jar, and then put some muscle on the ring after an hour or
so. That way, I know the beans are swamped in CO2. About an hour or so after
that, the top can't even pop in when you push on it.
At about 7 sq inches area, the lid multiplies the internal CO2 pressure to a
fair force that tends to push the lid offseat and allows the jar to outgas.
With the jar sitting upright,  the lighter O2 molecules rise to the top and
are expelled first.
It's not often that a full jar lasts me longer than a week [except Horse
and...], but I worried about the exchange of CO2 with fresh O2 when I open
the jar to dump beans into the scale pan.
I was going to either dip the beans out of the jar with a measuring spoon,
or subdivide the beans into some el-cheapo zip-lok sandwich baggies. Using
them individually would minimize the oxygen transfer. Not having the beans
around for very long also works good.
Sharon is already doing something similar to reuse the valved bags and still
keep the interiors  pristine.
Cheers -RayO, aka Opa!
The Zar looks scary- approach with caution. Get ready to Duck and Cover if
it starts ticking!

17) From: Justin Marquez
On 10/4/06, raymanowen  wrote:
<Snip>
I dunno... CO2 is 1.5x heavier than air, but in a confined space over
time at relatively warm temps (compared to absoulte zero, room temp is
DEFINITELY WARM) that Brownian molecular motion diffusion thingie
probably mixes whatever is in the jar. Heavy gases will hug the ground
- i.e. propane leaks will run along the ground for a ways before
mixing with air, for example - but eventually they dissipate, faster
on a windy day for sure.
Safe Journeys and Sweet Music
Justin Marquez (CYPRESS, TX)

18) From: Leo Zick
This is a multi-part message in MIME format.
using this methodology means that there must be a certain volume of beans to
canister space for your theory to work. how much empty space is required for
the co2 to extract all the oxygen?  or, worse yet, does each bean coupled
with each different type of roast create varying amounts of co2?
 
i think ill stick to 1/4lb valve bags, and just finish the stuff in 3-4
days. :o  
From: raymanowen [mailto:raymanowen] 
Sent: Wednesday, October 04, 2006 4:42 PM
To: homeroast
Subject: Re: +Re-use Roasted Coffee Bags?
"...if I screw the ring down, how does the gas escape?" 
Unscrew it, the same as you'd do to let some beans escape...
I think- unless the jars are tumbling around, the gasses would tend to
stratify in the jars. Especially if you just loosely cap them initially, the
CO2 will fill the jar and displace the O2 molecules out the top. 
I just fill the jar, and then put some muscle on the ring after an hour or
so. That way, I know the beans are swamped in CO2. About an hour or so after
that, the top can't even pop in when you push on it.
At about 7 sq inches area, the lid multiplies the internal CO2 pressure to a
fair force that tends to push the lid offseat and allows the jar to outgas.
With the jar sitting upright,  the lighter O2 molecules rise to the top and
are expelled first. 
It's not often that a full jar lasts me longer than a week [except Horse
and...], but I worried about the exchange of CO2 with fresh O2 when I open
the jar to dump beans into the scale pan.
I was going to either dip the beans out of the jar with a measuring spoon,
or subdivide the beans into some el-cheapo zip-lok sandwich baggies. Using
them individually would minimize the oxygen transfer. Not having the beans
around for very long also works good. 
Sharon is already doing something similar to reuse the valved bags and still
keep the interiors  pristine.
Cheers -RayO, aka Opa!
The Zar looks scary- approach with caution. Get ready to Duck and Cover if
it starts ticking! 

19) From: Leo Zick
But the coffee environment has all the ideals..standard atm pressure, temp,
ignore the principles of gravity and friction..  :p

20) From: raymanowen
"when you screw down the ring the lid can't move up (or down for that
matter) ."
There are physical realities that fly in the face of assumed properties in
the macroscopic world. To get the terms right, the rubber ring was the
gasket seal between the fruit jar and the lid. Both the ring and the lid
were secured to the jar by the band.
Look closely at the top of the fruit jar itself. It wasn't ground flat and
polished, so it's not very flat now. As such, it could not form a seal with
a hard flat closure.
Look at the jar's top sealing surface with a microscope- the gas molecules
do. It's so irregular that even the rubber seals would become too hard to
form a seal after a single long use or a couple of shorter uses with the
temperature cycles.
The metal band itself is made as a form of Belville spring. If you look at a
section view through the band (ring), it has an "L" shape. It's supported on
the vertical by being threaded to the jar, while the lid itself is pressed
by the short foot.
Those bands and lids didn't just happen. The metal thickness, hardness,
metallurgy and shape all contribute to a definite spring rate that forces
the lid to be a one-way valve as supplied.
The top rim of the blown jars is fire polished, but they have a precise
irregularity, as does the compliant seal material. The "orange peel" surface
appearance of the seal material itself is not the result of haphazard
application, like the paint job done by most body repair shops.
The irregularity and precise hardness of the seal ensure that there will be
areas of much lower than average unit pressure to allow the internal steam
pressure to unseat the seal and escape.
Unscientifically, I assume the seal goop stays more rigid at coffee storage
temperatures, vis a vis fruit canning temperatures, so I just snug the band
at the start and twist it down later. They work almost like they were
designed for coffee- wurks gud fer me.
For sending coffee to friends, I'll stick to the smaller coffee bags that
look verry much like el-cheapo Zip-lok sandwich bags. Maybe several of those
with 50g each of roast might be a neat calling card in a bubble wrap
envelope-
Cheers -RayO, aka Opa!
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