<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> I just had my third attempt at using the Cona end in a disaster. The water wasn't boiling and seemed to take an inordinate time to get close. Suddenly the water bubbled out the top of the bowl quite violently and seemed settle down and without thinking, I inserted the funnel with the aforementioned disasterous results. Coffee and grounds and water went immediately over everything. Other than stupidity, any chemical or physics reason anyone can think of? |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> Bill, I'm certainly no expert, having had my Cona for just a week, but I did the same thing. I let the water heat over the spirit lamp for 45 minutes without a boil. Actually the water never boils - look for the first bubble to rise (about 25 minutes on a cold start) and then insert the top. The siphon will react so slowly that you think it isn't working - then you'll notice moisture on the edges. It takes about a minute for the water to begin to rise rapidly. When the water clears the bottom of the tube the top will bubble wildly for a second as the air is pulled through. If you got coffee/grounds/water splashed out the top then it is probably too full - it should not splash out. I found that starting with boiling water made a superior process. I bought an electric kettle to do the boiling of the water - and it makes the whole process a piece of cake - or a cup of coffee? - but much easier. Hope this helps. John |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> Your water has superheated, Bill. It's gone past the 212F mark without actually boiling. I've had it happen to me, and after some discussion in alt.coffee, I learned to leave a glass marble in the bottom unit to help break the surface tension and get the water into a boil. Actually, you don't want a full boil. That's too hot for the coffee. You're looking for something around 203F when the water hits the grounds. I measure the water temp and insert the top unit when it hits about 205F. Give it a try. The marble will solve your problem, as will measuring the temperature of the water and letting the siphoning begin before it reaches the boiling point. Larry Palletti East Point/Atlanta, GA |
On 9/2/01 11:30 AM, Bill Cassady wrote: <Snip> Excessive vapor pressure? Seriously though, I have heard a theory of 'superheated water' put forward to explain this and apparently some explosions of Hario syphons but I'm not up on the science of it. Supposedly, insertion of the funnel upsets the equilibrium and causes an explosive reaction as the water suddenly begins normal boiling behavior all at once. You don't, however, need to let the water get to a boil before inserting the funnel. I usually wait until I just start to see condensed water vapor rising off the surface and coming out the mouth of the bowl. (But not just condensation forming on the bowl lip.) This seems to work fine for the Cona and Bodum Santos but is not such a reliable indicator with the Hario Nouveau, which seems to stat 'steaming' earlier. John Blumel homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast |
" ...I measure the water temp and insert the top unit when it hits about 205F..." wrote Larry. We don't have a Cona but have a manual and electrical Bodum Santos designs of the vacuum brewer. In the manual machine, we fill the bottom part with boiling water. In the electric machine, we fill the bottom part with a cold water. Than we insert the top unit with ground coffee and apply the heat. It works fine. Why do you first start the heat the water in the bottom unit and insert the top when the water heats up to about 205 degrees F? What is wrong with assembling the whole unit first? Also, although we had the "superheated water" problem in some other cases, we never happened with our vacuum coffee brewers. Perhaps the tube extending all the way into the bottom unit prevents it? Cheers, Lubos ... "So much to learn, so little time." homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast |
On 9/2/01 12:10 PM, Irene and Lubos Palounek wrote: <Snip> This might prevent the superheated water problem but it doesn't result in optimal brewing of ones coffee for the following reasons: 1. The vapor pressure will begin to push the water up into the funnel while it is relatively cool. 2. The water will take a very long time to finish rising into the funnel so at least some of the grounds will end up steeping for a very long time resulting in some degree of overextraction. In my experience, I get the best cup from vac pots when the funnel is inserted at a point where the water rapidly rises into the funnel but is not boiling in the bowl. John Blumel homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast |
" ...it doesn't result in optimal brewing of ones coffee for the following reasons: 1. The vapor pressure will begin to push the water up into the funnel while it is relatively cool. 2. The water will take a very long time to finish rising into the funnel so at least some of the grounds will end up steeping for a very long time resulting in some degree of overextraction ..." wrote John. (1) I thought that pre-wetting the ground beans is beneficial, not detrimental to the flavor and taste. (2) "Very long time" is a subjective term. It seems to me that the total "raising + bubbling" times are close to the optimal time in both cases -- when using the butane warmer under the manual brewer or the electric heat in the automated brewer. What do you consider the optimal brewing time -- both for the "hot water raising" and for the "bubbling" periods? Cheers, Lubos homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast |
On 9/2/01 1:35 PM, Irene and Lubos Palounek wrote: <Snip> If the funnel is inserted while the water is still cold, from the time the water first hits the grounds until the 'bubbling period' starts can be several minutes and the water that first hits the grounds will likely be significantly cooler. As far as, pre-wetting the grounds, I know that some -- e.g., some Solis models -- espresso machines have a pre-infusion cycle but my understanding is that this lasts for only a couple of seconds. I haven't really heard much about this in relation to other brewing methods but my personal experience with vacuum brewing suggests that it is not beneficial. In my opinion, the optimal length of time for the water to rise into the funnel, once it starts, is as fast as possible. I haven't actually timed this but I'd estimate 1 - 1.5 minutes. As far as the optimal 'bubbling period', I steep for ~50-60 seconds in the Cona or Santos -- depending on the grind -- and ~40 seconds in the Hario Nouveau. (The preceding based on 16 oz water + 5 Tbsp grounds or 32 oz water + 8 Tbsp grounds with a grind setting of 6-7 on a Solis 166.) John Blumel homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast |
<Snip> Well, I just brewed half a pot in the Santos and the time for the water to rise was 28 seconds so the time for a full pot should be pretty close to the lower estimate of 1 minute. John Blumel homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast |
With the denatured alcohol lamp it can be a very long time - over 5 min - between the first, cool wetting of the bottom of the grounds and the time most of the water moves up top. This is true even if you start with hot water. I have to boil my water, rinse everything with the boiling water to get it up to temp, then put in the amount of water I need to make it work. But when it works, it's wonderful. You do want to put the funnel in place before the water boils to give the steam time to build up pressure. You want the water to move up top before it boils but at a rapid pace. There was a long discussion on the *$ Utopia before we knew Bodum made their model available in the US and most of us gave very positive feedback about it. Anyone interested can check the archives. I got mine for $99, which made up for spending too much on the Hario. Bob C. rcantor |
<Snip> Has this been shown by actually measuring the water? I've noticed that many of the "discussions" in this list, and Alt.Coffee, can be solved by a simple empirical test of some sort. <Snip> <Snip> Just a thought... Ciao, Angelo homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast |
<Snip> Can you tell us where you got it for $99? Thanks, Angelo <Snip> homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast |
What's the point of "pre-wetting" the grounds? Isn't that why we are using the Cona, because it combines the water and grounds at the correct time? You might as well use a French Press. The Cona is not intended to be used for "instant coffee". steve homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast |
On Tue, 04 Sep 2001 12:25:48 -0400, Angelo wrote: <Snip> The water temp has not been measured by me but since all of the water in the bowl is cooler than if you wait, it is likely that the water which goes up almost immediately upon inserting the funnel will be somewhat cooler even if you assume some sort of chimney effect from the funnel tube and the point of contact of the alcohol burner. However the important point is that the water is in contact with at least some of the grounds for several minutes (I believe someone said ~5 minutes) longer than the 'bubbling period' time alone which, to my taste at least, results in a cup that is both more sour and bitter than when I insert the funnel at the point that water vapor rising off the water in the bowl becomes visible -- i.e., I don't find any benefit to preinfusion when vacuum brewing but rather that it is detrimental. John Blumel homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast |
Let me jump in as an expert here since I've had my Cona for 2 weeks now :O) There are several things that I've already found impact the brew. If I over-fill the pot (wanting four full mugs - and it can't be done) there isn't enough air to work the siphon. After stalling my pot a couple of times I finally realized that when it say not to fill beyond 1/2" it means it. Second thing that I discovered is that if you begin with boiling water, and then allow it to continue heating over the spirit lamp until you get rapid bubble formation and rise, then you've superheated the water and it will instantly go to the top and BOIL up there as well. It is a little forgiving - but those two things aren't covered. The steep time, the grind and all the rest seems to be forgiven. I no longer screen for dust since I a) started using the conical burr grinder, and fill to the right level - no stalls!! John - who really doesn't consider himself and expert at anything coffee related - except possibly swallowing it. |
<Snip>
I have measured the temperatures, but I use a Bodum Santos pot on a gas
stovetop. So I'm not sure whether this will apply to a Cona and spirit
lamp. The first thing I did when I got serious about making the pot work
(as opposed to just having a pretty piece of glass equipment on my shelf)
was to check out the temps at various stages.
I filled the bottom with water, put the top bowl on it with no coffee, and
waited for the water to rise into the top. The temperature I measured was
significantly lower than it should have been for proper brewing. I believe
it was 185-190F or so. I was surprised, because I didn't think the water
would rise until it boiled. Not so.
I measured the temp after all the water had risen into the top, so the
measured temp is the integration of all the water temps that hit the top
bowl. Presumably, the first water to hit the top was cooler because of
contact with the, initially, relatively cool glass tube and top bowl. It
was also cooler simply because this "early water" wouldn't have been heated
as long as the water that rose later during the brewing. But regardless of
the theories, the water in the top bowl was too cool for good brewing, and
would have resulted in a bitter/sour brew.
I took this to explain why my earlier halfassed attempts at vacuum brewing
had yielded really awful results.
Now I brew by heating up the water in the lower bowl alone, without having
the top bowl on it. When the water gets to about 205F, I put on the top
bowl containg the coffee. The water cools on the way up and when it hits
the cooler grounds, and results in a brewing temp of about 200F. The
coffee is generally superb from my Bodum Santos using this method.
-- garyZ
Whirley-drip(paper)-black
&vacuum(Santos)
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no. :) It was a combination of a *$ sale plus a friend who owed me a favor. Go to your nearest *$ and do some outrageous things for everyone there - save their lives, babysit their kids, and maybe you can get lucky, too. Of course one could say that it would be more cost effective to just buy the thing at full price... Bob C. rcantor |
Just received the shiny new Cona vac pot from SM. Great coffee - we're on the 2nd pot already. A note - The phrase "A watched pot never boils" seems to have a place here. I discovered that with 2 of us watching, the time to boil is extended by a factor of 2. McSparky - who will be starting the Cona W/hot water. |
yeah, unless you are having one of those i have nothing to do but time the boil from cold water, hot to start is always the best, they make great coffee don they!! On 4/6/06, M. McCandless wrote: <Snip> a <Snip> -- "Good night, and Good Coffee" |