Cory vacuum pot troubles

[Christopher S. Swingley]

Greetings!

I'm having some trouble with my Cory vacuum pot and I'm hoping for some
advice about where to turn next. My problem is that (as I'm sure you
can guess) it get's stuck more often than not. When I fill it with hot
water, no grounds, and let it fill the upper pot, after removing it from
the heat, in less than a minute the hot water rushes to the lower pot.

When I add coffee, sometimes (maybe 30%) coffee is made after a few
minutes of vacuum. But most of the time, after four or five minutes
I've got four cups of coffee and the liquid is barely trickling down the
tube. Not very satisfying, and even if I were to let it go another five
minutes, the coffee has been brewing for more than 10 minutes at this
point. I believe the coffee should be rushing down after I remove it
from the burner.

I initially used a whirly grinder, but now I've got a Zassenhaus hand
grinder and have been grinding coarser and coarser and it still sticks.
At the moment I'm a full turn past where the gears in the mill touch,
which is supposedly what's appropriate for a French press.

Is this the only variable, and do I just need to keep grinding coarser
and coarser until I hit the sweet spot? Or is there some other process
going on here that accounts for my extraordinary failure rate? Is the
Cory brand of vacuum brewer particularly sensitive or are other brands
better at actually **MAKING COFFEE**?

Sorry, getting frustrated. . .

One final question -- do I need to do something with the rubber gasket
between the glass parts? Based on the instruction booklet, it looks
like my pot dates back to the 50's. Should I be applying something
(Vaseline, Keg Lube, vegetable oil, etc.) to the rubber to keep it
flexible?

Thanks,

Chris

[Gak]

Post by Christopher S. Swingley
When I add coffee, sometimes (maybe 30%) coffee is made after a few
minutes of vacuum. But most of the time, after four or five minutes
I've got four cups of coffee and the liquid is barely trickling down the
tube. Not very satisfying, and even if I were to let it go another five
minutes, the coffee has been brewing for more than 10 minutes at this
point. I believe the coffee should be rushing down after I remove it
from the burner.

I've used a Cory glass rod for years and hardly ever had a 'stuck pot.' A
few things you can do to troubleshoot. When you get a stuck pot, is there
still a vacuum in the lower pot, or not? This is pretty eay to tell, by
trying to take them apart. If you can do it, there's probably no vacuum
left. Most of my suck pots are deu to a poor seal and loss of vacuum. When
you have coffee in there, you have to have a longer sustained vacuum and any
problems with the seal will cause a brew failure.

Also, I hav't done extensive testing with this, but I assume you're using
the glass Cory rod. Note that there are 2 types of rod, the original, and
the 'new' Cory rod. You can tell the difference here because the new ones
say 'New' on the side. There's a patent number difference as well, but the
'New' indicator should be enough. In any case, I use a 'New' Rod all the
time and it works great. Some poeple have said the original rods aren't as
nice.

Regarding grind- I don't know how the Zass mills work, but consistancy is
more important than grind size, in my experience. I use a Solis Maestro,
grinding just slightly coarser than what I used to use for espresso with
that grinder (before I picked up a Mazzer SJ). The grinder marking is right
above where the little portafilter is displayed on the grinder.

Post by Christopher S. Swingley
One final question -- do I need to do something with the rubber gasket
between the glass parts? Based on the instruction booklet, it looks
like my pot dates back to the 50's. Should I be applying something
(Vaseline, Keg Lube, vegetable oil, etc.) to the rubber to keep it
flexible?

I picked up a new one from food service direct a while back:
http://www.foodservicedirect.com/index.cfm/S/176/CLID/598/N/1368/Vacuum_Coffee_Makers.htm

They seem to be out of stock, and I hope they get more. These are a great
fit for Cory widemouth pots. My original gasket was a trashed.

One last note - some other people have had luck doing omse things with the
heat applied. Since I got a new gasket, I've rarely had a stuck pot, so I
haven't resorted to any tricks with the heat.

Good Luck!

-Garrik

[Christopher S. Swingley]

Garrik,

A few things you can do to troubleshoot. When you get a stuck pot, is
there still a vacuum in the lower pot, or not? This is pretty eay to
tell, by trying to take them apart.

Yep, there's a vacuum. The two pots are always hard to take apart and
there's a sucking noise when the do come apart. But I can't verify that
there's *enough* of a vacuum to pull the coffee through the grounds, and
given what you've said about your vacuum pot (fine grind, never sticks,
etc.), maybe this is my problem.

Also, I hav't done extensive testing with this, but I assume you're
using the glass Cory rod. Note that there are 2 types of rod, the
original, and the 'new' Cory rod. You can tell the difference here
because the new ones say 'New' on the side. There's a patent number
difference as well, but the 'New' indicator should be enough. In any
case, I use a 'New' Rod all the time and it works great. Some poeple
have said the original rods aren't as nice.

Hmm. I have two Cory rods (both glass). One has a round top and the
other one is square. Does this help identify them as "new" or "old"?
I've been using the round-topped one since it's the one that came with
the pot. They both have similar textures, but the square-topped one is
shaped slightly differently in the mid-section where it seals with the
filter tube. Maybe I'll give the square-topped rod a try next.

If you get a chance at some point, would you mind writing down the
patent numbers? If I were to pursue getting another rod, it seems that
the patent number is something eBay sellers will include in an auction
description. None of the auctions currently up say anything about the
word "new" appearing on the rod.

Regarding grind- I don't know how the Zass mills work, but consistancy
is more important than grind size, in my experience. I use a Solis
Maestro, grinding just slightly coarser than what I used to use for
espresso with that grinder (before I picked up a Mazzer SJ).

That sounds pretty fine! There's an instruction sheet at SweetMaria's
for the Cona vacuum pots and it mentions a grind just a bit coarser than
what would work for a filter machine. I'm grinding a lot coarser than
that and it still sticks!

Good Luck!

Thanks!

Chris

[BubbaBob]

Post by Christopher S. Swingley
Hmm. I have two Cory rods (both glass). One has a round top
and the other one is square. Does this help identify them as
"new" or "old"? I've been using the round-topped one since it's
the one that came with the pot. They both have similar
textures, but the square-topped one is shaped slightly
differently in the mid-section where it seals with the filter
tube. Maybe I'll give the square-topped rod a try next.
If you get a chance at some point, would you mind writing down
the patent numbers? If I were to pursue getting another rod, it
seems that the patent number is something eBay sellers will
include in an auction description. None of the auctions
currently up say anything about the word "new" appearing on the
rod.

Try to find a Silex rod. They have a spring and hook on them. They
work better in Cory pots than anything Cory ever made. BTW, the
'New" Cory rod is longer than the 'Old' and has a thinner cross-
section below the filtering area. I don't think that the square top
vs round top thing means anything other than age.

[Gak]

Post by Christopher S. Swingley
Yep, there's a vacuum. The two pots are always hard to take apart and
there's a sucking noise when the do come apart. But I can't verify that
there's *enough* of a vacuum to pull the coffee through the grounds, and
given what you've said about your vacuum pot (fine grind, never sticks,
etc.), maybe this is my problem.

If you;re having trouble getting them apart, then there's rpobably enough
vacuum. Sounds like you're having trouble with grind consistancy. You can
rpobably do some google searches for stuck vac pots and see, but as I
mentioned before, there are some tricks you can play with the heat
(somehting about turning up the heat near the end of the brew to get a
violent clearing out of the rod area before trying to draw the coffee down).
Either that, or matybe you could try grinding finer. Like I said before, I
think consistant grind size is key, and maybe the zass will provide more
consistant grind at a finer size.

Post by Christopher S. Swingley
If you get a chance at some point, would you mind writing down the
patent numbers? If I were to pursue getting another rod, it seems that
the patent number is something eBay sellers will include in an auction
description. None of the auctions currently up say anything about the
word "new" appearing on the rod.

Old Rod - Round top, shorter length, Patent #114097, says 'Cory Filter Rod'
on the side

New Rod - Square top, longer length, Patent #1927287, 1931076, 1935587 (all
3 on there), says 'New Cory Rod' on the side, and also has a bunch of
textured stuff on the top part (ridges and bumps between the roughened
surface where the filtering happens and the square top)

Anothe poster mentiones the Silex Lox-in. I've got one around here
somwhere, and I've never used it. I bought it figuring I"d give it a try,
and never really got around to it. It's got a spring/chain assembly on the
bottom that holds it in place so that nothing can get under it. It may help
in your situation, if you can find one.

Post by Christopher S. Swingley
That sounds pretty fine! There's an instruction sheet at SweetMaria's
for the Cona vacuum pots and it mentions a grind just a bit coarser than
what would work for a filter machine. I'm grinding a lot coarser than
that and it still sticks!

Part of how I arrived at my grind size (other than testing) was that I
remember hearing that part of the goal of the vac pot was to be able to
grind finer than drip methods. It makes sense to me that if you're relying
sololy on gravity, you have to grind coarser than if you're also using a
vacuum.

A few other thoughts I've had while writing this- You don't tell us anything
about your brewing procedure. I've had some oddball things happen until I
settled on this method for brewing. I fill the lower pot with cold water,
put it on medium heat, wait for it to get pretty steamy. Once it steams
regularly (but before boiling), I throw the top pot on, makgin sure to get
some of the water vapor on the gasket so it seals well. Then I wait for the
water to begin heading up. Once I see water actively heading to the top
pot, I grind the coffee, and throw it in the top. It's usually about
halfaway full by the time I'm done grinding. Then I stir it up, wait for
the 'first gurgle' that signifies the start of the brew time, let it sit for
90 seconds, then turn the heat off and move the pot to a cold burner. This
works for me, but YMMV.

One other oddity that I've noticed is that my pot behaves differently based
on when I wash it. When I'm vaccing regularly, I wash it right before I use
it. Sometimes I switch methods for a few days, and wash it and put it away.
When the pot it cold, the water flows differently, taking longer to start
the trip north, but making a violent trip when it does. This hasn't lead to
a stuck pot, but has made a mess more than once.

Again, good luck, and let us know how it goes!

-Garrik