Glass rod filter in vac pot -- fail!
- Peppersass
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I just acquired a Silex glass rod filter with spring for use with my Yama 3-cup vac pot. The rod fits fine, and water rises into the upper chamber with no problem, but I'm getting virtually no draw down. I've tried it with and without the spring, and there's no significant difference in the draw down. The spring does keep the rod from bobbling a lot when the water rises, but that's it.
First time I tried it, I used the grind setting that works for paper filters in the vac pot and my Technivorm drip machine. The second time I tried grinding as coarse as my Baratza Vario with metal Ditting burrs can go (though I could re-calibrate it to grind a bit coarser.) Is it normal to grind very coarse -- i.e., french press -- when using a glass rod?
Note that plain water draws down at about normal speed. It's just when I try to brew coffee that the draw down slows to a crawl.
Seems like the filter is sealing too well. Is there some trick I don't know about?
Could it be something to do with the shape of the rod? I happen to have a Cory rod (no spring) on the way, which should be here tomorrow. Thought I should get some opinions before potentially wasting more coffee.
First time I tried it, I used the grind setting that works for paper filters in the vac pot and my Technivorm drip machine. The second time I tried grinding as coarse as my Baratza Vario with metal Ditting burrs can go (though I could re-calibrate it to grind a bit coarser.) Is it normal to grind very coarse -- i.e., french press -- when using a glass rod?
Note that plain water draws down at about normal speed. It's just when I try to brew coffee that the draw down slows to a crawl.
Seems like the filter is sealing too well. Is there some trick I don't know about?
Could it be something to do with the shape of the rod? I happen to have a Cory rod (no spring) on the way, which should be here tomorrow. Thought I should get some opinions before potentially wasting more coffee.
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- Posts: 340
- Joined: 17 years ago
I haven't ever used that particular combination of brewers/filters.
But...although it sounds counter-intuitive - try grinding finer rather than coarser.
But...although it sounds counter-intuitive - try grinding finer rather than coarser.
- Boldjava
- Posts: 2765
- Joined: 16 years ago
Don't grind for press pot. Regardless of the quality of those Ditting burrs, it will throw fines. Fines are not a friend of vacpots with glass rods.
Go 25% finer grind than you do with a Technivorm grind. If it draws down, keep coming back to middle grind until it no longer works for you. I timed the draw-down on the Yama 5-cup (22 oz) this a.m., knowing this question was in the hopper. 1:10 to draw down after being lifted off the burner with a Corning rod.
For what it is worth, I have just the opposite problem with Silexes on my Yama stovetops. They permit a bit of "back and forth" between top and bottom while brewing. For me, they just don't seal as well as a Corning or a "New" Cory.
Just curious. Are you working with boiled water off a kettle before you play with that table top burner?
Go 25% finer grind than you do with a Technivorm grind. If it draws down, keep coming back to middle grind until it no longer works for you. I timed the draw-down on the Yama 5-cup (22 oz) this a.m., knowing this question was in the hopper. 1:10 to draw down after being lifted off the burner with a Corning rod.
For what it is worth, I have just the opposite problem with Silexes on my Yama stovetops. They permit a bit of "back and forth" between top and bottom while brewing. For me, they just don't seal as well as a Corning or a "New" Cory.
Just curious. Are you working with boiled water off a kettle before you play with that table top burner?
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LMWDP #339
LMWDP #339
- yakster
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Don't stir, just dunk the grounds at the start with a spoon or paddle.
-Chris
LMWDP # 272
LMWDP # 272
- Boldjava
- Posts: 2765
- Joined: 16 years ago
Ab. So. Lute. Ly.
There is sufficient agitation to properly extract without stirring. One push down all the way around with a rice paddle is fine (wooden spoon works).
There is sufficient agitation to properly extract without stirring. One push down all the way around with a rice paddle is fine (wooden spoon works).
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LMWDP #339
LMWDP #339
- kaldi61
- Posts: 266
- Joined: 9 years ago
I would consider trying a Cory rod. I use a Yama 5-cup and it fits perfectly.
Ditto on Boldjava's recommendations re: grind. It seems counter-intuitive, but you should go finer than you describe.
Ditto on Boldjava's recommendations re: grind. It seems counter-intuitive, but you should go finer than you describe.
-Nelson
LMWDP #506 "It's not just for breakfast anymore."
LMWDP #506 "It's not just for breakfast anymore."
- Peppersass (original poster)
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No. I fill the lower globe from the tea water tap of my espresso machine. I'm using a halogen heater to take it from there. After the water rises, it's in the 199F-200F range.Boldjava wrote:Just curious. Are you working with boiled water off a kettle before you play with that table top burner?
- Boldjava
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- Joined: 16 years ago
...and then the coffee goes in. Might want to run it a bit higher. Coffee will pull that temp down a bit.
You will get it.
You will get it.
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LMWDP #339
LMWDP #339
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Recently purchased a Cory rod for my 8-cup Yama after realizing how gross the cloth filter had become. Took just a few days of the "keeping it clean" ritual to hit the auction site for a Cory.
First thing I noticed about the rod was a "seam line" on the ball of the filter. Thought that might let fines slip by but wasn't quite ready to pull out the Dremel. After using the rod for a few days, I decided the seam is there to prevent a too perfect seal. Or...maybe it's just how the rod is manufactured.
Current routine is to let most if not all of the water move into the upper chamber before dumping in the coffee. I give a quick, shallow stir with a chop stick, set a timer for 2 minutes, then move the pot to a cutting board and walk away rather than watching the slow draw into the lower pot. Coffee is decanted into a thermos. There are a few fines in the pot but *very* few so maybe a teaspoon of coffee is wasted.
Electric kettle first - definitely.
Still playing with brew times.
First thing I noticed about the rod was a "seam line" on the ball of the filter. Thought that might let fines slip by but wasn't quite ready to pull out the Dremel. After using the rod for a few days, I decided the seam is there to prevent a too perfect seal. Or...maybe it's just how the rod is manufactured.
Current routine is to let most if not all of the water move into the upper chamber before dumping in the coffee. I give a quick, shallow stir with a chop stick, set a timer for 2 minutes, then move the pot to a cutting board and walk away rather than watching the slow draw into the lower pot. Coffee is decanted into a thermos. There are a few fines in the pot but *very* few so maybe a teaspoon of coffee is wasted.
Electric kettle first - definitely.
Still playing with brew times.
- Peppersass (original poster)
- Supporter ❤
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- Joined: 15 years ago
The Cory rod arrived.
The Technivorm grind setting is 6 out of 10, so I set it to 4 for the first test. Let the water rise, dumped in the grounds and tamped the down under the water. Let steep for 35 seconds and removed from the heat. No luck -- draw down stalled. Couldn't get it to go even by cooling the lower globe with a cold wet cloth.
Then I moved the grind setting to the finest the Vario with Ditting burrs will go -- not quite espresso grind. This time the draw-down was still slow, but it did progress. Total draw-down time was about 6 minutes 30 seconds and, as you might expect, the coffee was badly over-extracted: about 24.5% extraction yield as measured on a VST refractometer with CoffeeTools.
Then I read the box the Cory came in. It said to put the rod in the upper globe, add the coffee, and set the heat low so the water rises slowly. I've always let the water rise quickly, added the grounds after the rise and tamped them under the water. I decided that the super fine grind didn't make a big enough difference in the draw-down time, so I'd try the Cory instructions. I went back to grind setting 4, which I guessed was around the 25% finer recommended by Boldjava
Placed the rod, dumped in the coffee and assembled the vac pot. As the water rose, I wasn't quite sure where to set the heat, so I played with it a bit. The grounds formed a cake that floated up on top of a column of light colored water that only had a few bits of coffee in it. Towards the end of the rise, the gurgling around the rod caused agitation that made the coffee mix with the column of water quite a bit. I only had to push the top of the cake down a little to saturate the grounds.
The Cory instructions say to let the water gurgle for at least one minute for finely ground coffee, two minutes for coarsely ground coffee. My habit is to let the coffee steep for about 35 seconds, so that's what I did. Removed from the heat, did not stir, and after a short pause a more normal draw-down began. I used a cold wet cloth to speed it along. Total draw-down time was about 2 minutes, somewhat longer than what I get with a paper filter, which usually runs 1:00-1:30, but close enough to normal to be encouraging.
I thought with the longer draw-down time the brew would still be under-extracted, but it came out at 19.38%, only slightly off my target of 20%. Could be that I didn't stir after removing from the heat. There are some variables to play with to get the extraction yield up, like grinding one stop finer or coarser, steeping longer, stirring after taking off the heat, not cooling the lower globe, etc.
So it seems that the difference was placing the grounds in the globe before the rise instead of after. I've seen videos of the former, but have always done the latter. Could that really be the difference between clogging the filter and a normal draw-down?
BTW, I was impressed by the lack of coffee particles in the cup and the fuller body compared with the paper filter.
The Technivorm grind setting is 6 out of 10, so I set it to 4 for the first test. Let the water rise, dumped in the grounds and tamped the down under the water. Let steep for 35 seconds and removed from the heat. No luck -- draw down stalled. Couldn't get it to go even by cooling the lower globe with a cold wet cloth.
Then I moved the grind setting to the finest the Vario with Ditting burrs will go -- not quite espresso grind. This time the draw-down was still slow, but it did progress. Total draw-down time was about 6 minutes 30 seconds and, as you might expect, the coffee was badly over-extracted: about 24.5% extraction yield as measured on a VST refractometer with CoffeeTools.
Then I read the box the Cory came in. It said to put the rod in the upper globe, add the coffee, and set the heat low so the water rises slowly. I've always let the water rise quickly, added the grounds after the rise and tamped them under the water. I decided that the super fine grind didn't make a big enough difference in the draw-down time, so I'd try the Cory instructions. I went back to grind setting 4, which I guessed was around the 25% finer recommended by Boldjava
Placed the rod, dumped in the coffee and assembled the vac pot. As the water rose, I wasn't quite sure where to set the heat, so I played with it a bit. The grounds formed a cake that floated up on top of a column of light colored water that only had a few bits of coffee in it. Towards the end of the rise, the gurgling around the rod caused agitation that made the coffee mix with the column of water quite a bit. I only had to push the top of the cake down a little to saturate the grounds.
The Cory instructions say to let the water gurgle for at least one minute for finely ground coffee, two minutes for coarsely ground coffee. My habit is to let the coffee steep for about 35 seconds, so that's what I did. Removed from the heat, did not stir, and after a short pause a more normal draw-down began. I used a cold wet cloth to speed it along. Total draw-down time was about 2 minutes, somewhat longer than what I get with a paper filter, which usually runs 1:00-1:30, but close enough to normal to be encouraging.
I thought with the longer draw-down time the brew would still be under-extracted, but it came out at 19.38%, only slightly off my target of 20%. Could be that I didn't stir after removing from the heat. There are some variables to play with to get the extraction yield up, like grinding one stop finer or coarser, steeping longer, stirring after taking off the heat, not cooling the lower globe, etc.
So it seems that the difference was placing the grounds in the globe before the rise instead of after. I've seen videos of the former, but have always done the latter. Could that really be the difference between clogging the filter and a normal draw-down?
BTW, I was impressed by the lack of coffee particles in the cup and the fuller body compared with the paper filter.