How does the filter process work and what does the glass rod do?
Help with Cory Vacuum Coffee Pot
- Thread starter ea56
- Start date
Help Support :
The glass rod has a rough surface where it fits into the top bowl. The force of the heated water rising into the upper bowl prevents the coffee in the upper bowl from falling into the lower bowl as long as the pot remains over heat. Once the brewing time is up and the pot is removed from the source of heat the lower bowl will begin to cool. This change in temp. creates the vacuum that draws the coffee down into the pot. As the brewed coffee is "pulled" down to the pot below the wet coffee grounds collect against the glass rod's rough surface and only the liquid coffee passes thru into the lower pot. If another type of filter is used, such as a frame with a cloth filter attached the process is essentially the same with the exception that the wet coffee grounds are instead filtered out of the finished brew by the cloth or wire mesh if used. This is a rather simplfied explanation of the process. That being said, the Cory Glass Rod is an ingenious invention. Some people don't care for them,but if you use a grind coffee that is med. rather than very fine these filters work very well.
Eddie[this post was last edited: 12/8/2015-22:58]
Eddie[this post was last edited: 12/8/2015-22:58]
Thanks Eddie for the explanation!
Now that's a darn shame.
<span style="font-family: verdana,geneva;">All these Estate Sales I've seen these and passed them up. I figured without some kind of cloth or mesh filter in place you would get a read "muddy" cup of coffee which I don't like. About a month ago I let a NIB one pass on an Estate Sale. It was marked $35 and it was 1/2 off day.</span>
<span style="font-family: verdana,geneva;">I liked the Yama and the Sunbeam Coffeemasters because of the cloth filter and even thought the coffee is a little cloudy it doesn't have a lot of sediment that I thought you would get with that glass rod type filer.</span>
<span style="font-family: verdana,geneva;">Question: I don't' heat the water separately and then transfer it. Is it really that much faster? I figured I was going to have to heat the water either way so I didn't think I was saving much time by heating it separately and then transferring it.</span>
<span style="font-family: verdana,geneva;">All these Estate Sales I've seen these and passed them up. I figured without some kind of cloth or mesh filter in place you would get a read "muddy" cup of coffee which I don't like. About a month ago I let a NIB one pass on an Estate Sale. It was marked $35 and it was 1/2 off day.</span>
<span style="font-family: verdana,geneva;">I liked the Yama and the Sunbeam Coffeemasters because of the cloth filter and even thought the coffee is a little cloudy it doesn't have a lot of sediment that I thought you would get with that glass rod type filer.</span>
<span style="font-family: verdana,geneva;">Question: I don't' heat the water separately and then transfer it. Is it really that much faster? I figured I was going to have to heat the water either way so I didn't think I was saving much time by heating it separately and then transferring it.</span>
Ralph, to answer your question about heating the water first for vac pot coffee, yes, I really do find that it is faster. And I think the finished brew is better too, because the water is at the correct temp for brewing when it hits the ground coffee. I found that when I started the pot full, from cold, the water would start to rise before it came to a boil. And on med heat would take almost 20 mins from start to finish to brew a pot of coffee. When I start the pot with 3/4" of water on med heat while I boil the rest of the water in my electric kettle I can brew 6 to 8 cups in 10 to 12 mins.
Also, I have used my Cory Glass Rod in my 8 cup Yama and both of my Coffeemasters, with excellent results. A Cory rod gives a clearer finished brew than a wire mesh filter, but the cloth filter does, in my opinion give the clearest brew, but not that much more clear than the Cory rod. And the cloth filters are a PITA to keep clean. The glass rod just requires a rinse. I've noticed that Cona now makes a glass filter rod that many people like to use instead of the cloth filter. Coffee made with the glass rod has a more pure flavor because there is nothing foreign coming in contact with the coffee, no paper, no cloth, no metal, just glass.
Eddie
Also, I have used my Cory Glass Rod in my 8 cup Yama and both of my Coffeemasters, with excellent results. A Cory rod gives a clearer finished brew than a wire mesh filter, but the cloth filter does, in my opinion give the clearest brew, but not that much more clear than the Cory rod. And the cloth filters are a PITA to keep clean. The glass rod just requires a rinse. I've noticed that Cona now makes a glass filter rod that many people like to use instead of the cloth filter. Coffee made with the glass rod has a more pure flavor because there is nothing foreign coming in contact with the coffee, no paper, no cloth, no metal, just glass.
Eddie
Muddy Coffee
It all depends upon the grind....
Back in the day vacuum coffee makers came with instructions telling Madame or whomever what sort of grind they should use that suited whatever filter system was in place.
Find both with Cory and Silex glass rods cannot use most store bought pre-ground coffees. They are just too fine/powdery and you end up with muddy coffee (lots of sediment). OTOH using a cloth filter system such as those by Silex gives clear and wonderful coffee regardless of grind, even the most fine.
Glass rods and other such systems came about to get away from what many considered the bothersome and unhygienic cloth filters. These had to be cleaned and kept soaking but no matter how you did things it amounted to reusing a dirty filter. Obviously you cannot wash the things with soap or detergent because of residue. Boiling even with bleaches will restore whiteness but may not get at the oils left from coffee brewing.
I grind my beans just before brewing. Have my grinder set to give just the proper coffee for glass rod brewing.
As for NIB and other vac pots showing up at estate sales...
Many housewives got several of these systems as wedding gifts. More may have come during their marriage as gifts as well. Either way by the 1950's and certainly 1960's automatic drip coffee was making huge inroads into the market. That and of course automatic perk pots.
Though vacuum coffee systems can give great results the lure of fully automatic coffee making won out. Some like Sunbeam did try with their model C-50, but the ship had set sail.... In any event these "extras" sat around unused just waiting to be discovered by persons like us.
It is amazing to see where vac pot prices are today. Back when eBay was young (and so was I for that matter) you could nab NIB sets for very little money. Now even good used go for dear prices.
It all depends upon the grind....
Back in the day vacuum coffee makers came with instructions telling Madame or whomever what sort of grind they should use that suited whatever filter system was in place.
Find both with Cory and Silex glass rods cannot use most store bought pre-ground coffees. They are just too fine/powdery and you end up with muddy coffee (lots of sediment). OTOH using a cloth filter system such as those by Silex gives clear and wonderful coffee regardless of grind, even the most fine.
Glass rods and other such systems came about to get away from what many considered the bothersome and unhygienic cloth filters. These had to be cleaned and kept soaking but no matter how you did things it amounted to reusing a dirty filter. Obviously you cannot wash the things with soap or detergent because of residue. Boiling even with bleaches will restore whiteness but may not get at the oils left from coffee brewing.
I grind my beans just before brewing. Have my grinder set to give just the proper coffee for glass rod brewing.
As for NIB and other vac pots showing up at estate sales...
Many housewives got several of these systems as wedding gifts. More may have come during their marriage as gifts as well. Either way by the 1950's and certainly 1960's automatic drip coffee was making huge inroads into the market. That and of course automatic perk pots.
Though vacuum coffee systems can give great results the lure of fully automatic coffee making won out. Some like Sunbeam did try with their model C-50, but the ship had set sail.... In any event these "extras" sat around unused just waiting to be discovered by persons like us.
It is amazing to see where vac pot prices are today. Back when eBay was young (and so was I for that matter) you could nab NIB sets for very little money. Now even good used go for dear prices.
Laundress, I use store bought ground coffee and I don't end up with muddy coffee. I do find a very small amount of very fine sediment in the last cup, but I don't find this bothersome. In fact the sediment is less than I have experienced using either a Coffeemaster with the Stainless steel mesh filter or a French Press. I guess it's all a matter of personal taste. I will gladly trade the pure taste of coffee with very small amounts of sediment to avoid the off taste that a dirty cloth filter or paper filter can impart.
Eddie
Eddie
Pre-Ground coffee varies
So yes, you can find some will work with vac pots, others won't depending upon filter system used. Generally the finer grind say as for espresso causes more problems for glass rod filters.
I've used several brands of K-cups in my Silex without problems.
If using any flavored coffee I always use glass rod filters. You cannot get that Hazelnut flavoring out of cloth filters. *LOL*
So yes, you can find some will work with vac pots, others won't depending upon filter system used. Generally the finer grind say as for espresso causes more problems for glass rod filters.
I've used several brands of K-cups in my Silex without problems.
If using any flavored coffee I always use glass rod filters. You cannot get that Hazelnut flavoring out of cloth filters. *LOL*
Old Dog - New Tricks
<span style="font-family: verdana, geneva;">Eddie, </span>
<span style="font-family: verdana, geneva;">I am a little horrified by a couple of things this morning. </span>
<span style="font-family: verdana, geneva;">First, I had no idea that the water would rise into the coffee at such low temps. My target is around 197 or so and I always thought that the temp of the water (near boilng) was what caused the water to start to rise to the top. I was shocked to test the water temperature using my method and to find it was only around 100.</span>
<span style="font-family: verdana, geneva;">So I did an experiment based on my method and then yours:</span>
<ul>
<li><span style="font-size: 12pt; font-family: verdana, geneva;">Photo 3: Mine - The water starts to rise at a little over 80.</span></li>
<li><span style="font-family: verdana, geneva;">Photo 4: Mine - It maxes out at around 188 (a little less than I would like). And the second reason I was horrified. I thought that was a clean filter and look at that water. Thank you Laundress. I never would have thought I was drinking that!!!!!</span></li>
<li><span style="font-family: verdana, geneva;">Photo 7: Yours - As soon as I put the top on the water shot up into the bowl and the temp also shot up quickly to over 200. I mean it didn't rise slowly as in my method it SHOT into the bowl and it was HOT!!</span></li>
<li><span style="font-family: verdana, geneva;">Photo 8: Yours - Looks like it maxed out at around 211</span></li>
</ul>
<span style="font-family: verdana, geneva;">I will definitely use yours moving forward. </span>
<span style="font-family: verdana, geneva;">Laundress, not sure what to do about this filter situation but I think I will look for a Cory Glass Rod. I see them often on Fleabay!! Can you only imagine what the filter in Daisys' pot looks like?
</span>
<span style="font-family: verdana, geneva;">Thank you both!</span>
<span style="font-family: verdana, geneva;">Eddie, </span>
<span style="font-family: verdana, geneva;">I am a little horrified by a couple of things this morning. </span>
<span style="font-family: verdana, geneva;">First, I had no idea that the water would rise into the coffee at such low temps. My target is around 197 or so and I always thought that the temp of the water (near boilng) was what caused the water to start to rise to the top. I was shocked to test the water temperature using my method and to find it was only around 100.</span>
<span style="font-family: verdana, geneva;">So I did an experiment based on my method and then yours:</span>
<ul>
<li><span style="font-size: 12pt; font-family: verdana, geneva;">Photo 3: Mine - The water starts to rise at a little over 80.</span></li>
<li><span style="font-family: verdana, geneva;">Photo 4: Mine - It maxes out at around 188 (a little less than I would like). And the second reason I was horrified. I thought that was a clean filter and look at that water. Thank you Laundress. I never would have thought I was drinking that!!!!!</span></li>
<li><span style="font-family: verdana, geneva;">Photo 7: Yours - As soon as I put the top on the water shot up into the bowl and the temp also shot up quickly to over 200. I mean it didn't rise slowly as in my method it SHOT into the bowl and it was HOT!!</span></li>
<li><span style="font-family: verdana, geneva;">Photo 8: Yours - Looks like it maxed out at around 211</span></li>
</ul>
<span style="font-family: verdana, geneva;">I will definitely use yours moving forward. </span>
<span style="font-family: verdana, geneva;">Laundress, not sure what to do about this filter situation but I think I will look for a Cory Glass Rod. I see them often on Fleabay!! Can you only imagine what the filter in Daisys' pot looks like?
</span><span style="font-family: verdana, geneva;">Thank you both!</span>
brucelucenta
Well-known member
- Joined
- Jul 21, 2013
- Messages
- 1,924
Pretty and interesting to look at. Not very practical though. Which is why there have been improvements since those were made….Try a new Kerig coffee machine and step into the 21st century.
Have always allowed the water to rise near simmering
Temperature *then* place the upper globe on my Silex or Cory vacuum pots (latter is long since gone...). Learned this from early days on Coffeekid.com and also when a bunch of us were on Usenet (remember that?) newsgroups such as alt.coffee.
Rule #1. Never boil coffee! Water temp should be around 195 or so IIRC, but not at 212F. Easy method to judge is when seeing just wafts of steam coming from the lower globe or the "simmering" sound with small bubbles forming you get as water reaching the boiling stage. Some actually do use a thermometer to detect proper temperature but I don't have that kind of time first thing in AM. It is all one can do to get the coffee going without breaking anything or whatever.....
Temperature *then* place the upper globe on my Silex or Cory vacuum pots (latter is long since gone...). Learned this from early days on Coffeekid.com and also when a bunch of us were on Usenet (remember that?) newsgroups such as alt.coffee.
Rule #1. Never boil coffee! Water temp should be around 195 or so IIRC, but not at 212F. Easy method to judge is when seeing just wafts of steam coming from the lower globe or the "simmering" sound with small bubbles forming you get as water reaching the boiling stage. Some actually do use a thermometer to detect proper temperature but I don't have that kind of time first thing in AM. It is all one can do to get the coffee going without breaking anything or whatever.....
Home - CoffeeKid!
coming soon An intense coffee obsession is about to materialize Days Hours Minutes Seconds
coffeekid.com
I am going to try that.
<span style="font-family: verdana,geneva;">Now that I think about it I shouldn't have had the water boiling I should have let it simmer as you state. I remember from my Chemex days when to tell how the water is right about 197 or so which I know is where it should be. </span>
<span style="font-family: verdana,geneva;">I guess in my brain I am still in this place of it has to boil to rise to the top of the vacuum pot and I see now that's not the case. I will experiment more to see if I can get it around that 197 mark when it rises to the top.</span>
<span style="font-family: verdana,geneva;">If it's not the temperature that makes it rise then what is it that creates the vacuum? If is the temperature it must be much lower than I thought it was.</span>
<span style="font-family: verdana,geneva;">Now that I think about it I shouldn't have had the water boiling I should have let it simmer as you state. I remember from my Chemex days when to tell how the water is right about 197 or so which I know is where it should be. </span>
<span style="font-family: verdana,geneva;">I guess in my brain I am still in this place of it has to boil to rise to the top of the vacuum pot and I see now that's not the case. I will experiment more to see if I can get it around that 197 mark when it rises to the top.</span>
<span style="font-family: verdana,geneva;">If it's not the temperature that makes it rise then what is it that creates the vacuum? If is the temperature it must be much lower than I thought it was.</span>
ovrphil
Well-known member
Launderess - I do remmember use.net and boards I'd subscribe to. With a 25mz clock doubling Tandy(marked D.E.C)machine, I was on the web in 1990-91(reportedly, only a million users at that time). I still have an early version of Mozilla /Netscape that has the animated .gif Dragon. So cool, the fire coming out of the dragon's mouth. It was an introductory version, just wet behind the ears.
SCAA recommendts 92-96C max, preferably as you know, 197-200F seems ideal. I notice our best percolator coffee maker will reach a high temp(never measured it yet)early and maintains it during the entire brew process. I have to manually turn it off, as it won't turn off by itself anymore. Good coffee is a necessity - Thomas Jefferson said wine was a necessity, but he forgot the other liquid. :- )LOL.
SCAA recommendts 92-96C max, preferably as you know, 197-200F seems ideal. I notice our best percolator coffee maker will reach a high temp(never measured it yet)early and maintains it during the entire brew process. I have to manually turn it off, as it won't turn off by itself anymore. Good coffee is a necessity - Thomas Jefferson said wine was a necessity, but he forgot the other liquid. :- )LOL.
whirlcool
Well-known member
I have three or four extra Cory glass rods. If you can get your address to me, I'll mail one off to you.
Thank you Allen
<span style="font-family: verdana,geneva;">Should I use the Email address in your profile?</span>
<span style="font-family: verdana,geneva;">Should I use the Email address in your profile?</span>
whirlcool
Well-known member
Yes, send your address to that e-mail and I'll receive it. I'm the only one that ever looks in that mailbox.
I finally received my Cory pot yesterday. I had to try it right away. I used the pot directly on the glass top stove without the trivet. It was fun to watch the water get drawn up into the top and then get drawn back down after removing the pot from the heat. I found it took awhile for the water to boil so I'm going to try the method of boiling an inch of water in the pot and using a kettle to boil the rest. The only thing I didn't like is cleaning the coffee grounds from the top part as I don't want to wash them down the drain. I did like the taste of the coffee. I ground some fresh beans using my burr mill. I'll only be using the cory on weekends when I have more time...during the week I will stick with the Keurig.
Gary
Gary
Gary
I hear you about letting the grounds go down the drain!
(0ld house, old pipes, and no disposer here)
Ive never used a Cory, but with the Coffeemaster.. I leve the grounds in the upper bowl til they dry out. When their dry.. they fall out easier into the garden or trash pail.
HTH
I hear you about letting the grounds go down the drain!
(0ld house, old pipes, and no disposer here)
Ive never used a Cory, but with the Coffeemaster.. I leve the grounds in the upper bowl til they dry out. When their dry.. they fall out easier into the garden or trash pail.
HTH
My house is on a septic system which is why I don't want the grounds to go down the drain.
I tried the method today of bringing to a boil only an inch or so of water in the lower pot and using a kettle to boil the water then pouring that into the lower pot. Almost immediately the water rose to the upper pot. When I removed the pot from the heat, the coffee in the top did NOT get drawn back down to the bottom pot. Not sure why but I think I will stick with bringing all the water to a boil in the lower pot rather than using a kettle.
I tried the method today of bringing to a boil only an inch or so of water in the lower pot and using a kettle to boil the water then pouring that into the lower pot. Almost immediately the water rose to the upper pot. When I removed the pot from the heat, the coffee in the top did NOT get drawn back down to the bottom pot. Not sure why but I think I will stick with bringing all the water to a boil in the lower pot rather than using a kettle.
Gary,
when you get a "stall" and the coffee won't siphon back to the lower pot I've found the it is usually due to the coffee being too finely ground. Sometimes you can get a "stall" to begin draining by slightly cooling the lower pot, either by blowing on it or placing a slightly damp cloth over the pot, therby causing it to cool and start the siphon process.
Eddie
when you get a "stall" and the coffee won't siphon back to the lower pot I've found the it is usually due to the coffee being too finely ground. Sometimes you can get a "stall" to begin draining by slightly cooling the lower pot, either by blowing on it or placing a slightly damp cloth over the pot, therby causing it to cool and start the siphon process.
Eddie
