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Tea pot spout dripping
Posted: Tue Dec 12, 2017 8:37 pm
by ChaLover
What is the forum's opinion about the importance of a tea pot that does not drip from its spout after pouring tea into cups or pitchers as a deciding facture in purchasing and/or over other engineering considerations?
I have pots that never drip and some that always do. I tend to prefer to buy pots that cut the water precisely and cleanly, but that requirement greatly limits my pot choices.
Re: Tea pot spout dripping.
Posted: Tue Dec 12, 2017 11:07 pm
by Chadrinkincat
For vintage pots things like drips and loose lids is common. It's nice if you find one w/o flaws but doesn't really effect my purchase much.
For modern pots it's the opposite. I wouldn't buy one that had any flaws. There's no reason any of those things should exist unless it's a cheap poorly made pot. Harder to avoid if buying online though.
Re: Tea pot spout dripping.
Posted: Wed Dec 13, 2017 2:17 am
by Atlas
For what it's worth (and I know someone's going to crucify me for suggesting this) a strategically-placed swipe of food-safe silicone grease (like Molykote 111) under the lip edge is often enough to ensure a perfect pour. Invisible, and you might have to reapply maybe every six months.
Re: Tea pot spout dripping.
Posted: Thu Dec 14, 2017 7:23 am
by Chingwa
Atlas wrote: ↑Wed Dec 13, 2017 2:17 am
grease
Re: Tea pot spout dripping.
Posted: Thu Dec 14, 2017 11:20 am
by Elise
I personally do not feel very comfortable with that kind of products. And if you have to reapply, it means to me that the grease goes somewhere (in the tea you drink)
Re: Tea pot spout dripping.
Posted: Thu Dec 14, 2017 11:51 am
by Victoria
Atlas wrote: ↑Wed Dec 13, 2017 2:17 am
For what it's worth (and I know someone's going to crucify me for suggesting this) a strategically-placed swipe of food-safe silicone grease (like Molykote 111) under the lip edge is often enough to ensure a perfect pour. Invisible, and you might have to reapply maybe every six months.
Mmm interesting solution makes me think then that a drop of Kintsugi might also be a
visible fix. I can deal with a loose lid by pouring more slowly, but a drippy spout is annoying especially with smaller pots and high quality teas where every drop counts.
Re: Tea pot spout dripping.
Posted: Thu Dec 14, 2017 4:11 pm
by steanze
ChaLover wrote: ↑Tue Dec 12, 2017 8:37 pm
What is the forum's opinion about the importance of a tea pot that does not drip from its spout after pouring tea into cups or pitchers as a deciding facture in purchasing and/or over other engineering considerations?
I have pots that never drip and some that always do. I tend to prefer to buy pots that cut the water precisely and cleanly, but that requirement greatly limits my pot choices.
If it's a new pot, it shouldn't drip, otherwise the craftsmanship is really bad. For an older pot, I don't mind much. I empty the pot in a pitcher anyway, I don't stop half-way. There are more important things to consider.
Re: Tea pot spout dripping.
Posted: Thu Dec 14, 2017 7:05 pm
by Bok
steanze wrote: ↑Thu Dec 14, 2017 4:11 pm
I don't stop half-way. There are more important things to consider.
Exactly! Some people might need that tiny stop if they use Chaozhou brewing though. But even then most people just put the cups very close together and don’t mind the spillover that happens.
Re: Tea pot spout dripping.
Posted: Fri Dec 15, 2017 2:50 am
by Atlas
Victoria wrote: ↑Thu Dec 14, 2017 11:51 am
Atlas wrote: ↑Wed Dec 13, 2017 2:17 am
For what it's worth (and I know someone's going to crucify me for suggesting this) a strategically-placed swipe of food-safe silicone grease (like Molykote 111) under the lip edge is often enough to ensure a perfect pour. Invisible, and you might have to reapply maybe every six months.
Mmm interesting solution makes me think then that a drop of Kintsugi might also be a
visible fix.
Perhaps, though I think there'd be a good chance of just giving the tea a rounder path to stick to - in terms of geometry you really want a sharp, undercut edge at the lower lip at the earliest possible point where you expect tea to come out (ie the angle where a full pot starts pouring).
The point of the grease is to provide a hydrophobic barrier where highly-wettable clay would otherwise provide an easy path down the side of the pot - if lacquer is anything like epoxy it's comparably-wettable to clay for our purposes.
Elise wrote: ↑Thu Dec 14, 2017 11:20 am
I personally do not feel very comfortable with that kind of products. And if you have to reapply, it means to me that the grease goes somewhere (in the tea you drink)
I suspect it's far more likely rubbed off on my tea-towel when I rinse and dry my pots (used to be after every use back when I had drippy pots. It cannot dissolve, nor just "fall off" during a pour. To each their own, though.
Re: Tea pot spout dripping.
Posted: Sun Dec 17, 2017 9:00 pm
by beachape
Poor lid-fit really drives me nuts. I bought a 90s shui-ping and it drips despite being a very attractive pot. What has changed since the 90s in pot manufacturing that allows cheaper pots to have a great lid fit?
Re: Tea pot spout dripping.
Posted: Wed Feb 10, 2021 5:22 pm
by LeoFox
Found an interesting article about the physics of spout dripping
Lay person summary:
https://www.technologyreview.com/2009/1 ... ot-effect/
Primary reference:
https://arxiv.org/abs/0910.3306
The problem with teapots is their annoying habit of dribbling, particularly at low rates of flow. The phenomenon has achieved such notoriety that it has been imaginatively dubbed the “teapot effect”.
Previous studies have shown that a number of factors effect this process such as the radius of curvature of the teapot lip, the speed of the flow and the “wettability” of the teapot material. But a full understanding of what’s going on has so far eluded scientists.
Now Cyril Duez at the University of Lyon in France and a few amis, have identified the single factor at the heart of the problem and shown how to tackle it. They say that the culprit is a “hydro-capillary” effect that keeps the liquid in contact with the material as it leaves the lip. The previously identified factors all determine the strength of this hydro-cappillary effect.
So how to overcome it? There are two ways say Duez and co. The first is to make the lip as thin as possible. That’s why teapots with spouts made from thin metal are less likely to dribble.
The second is to coat the lip with the latest generation of superhydrophobic materials which strongly repel water.
Re: Tea pot spout dripping.
Posted: Wed Feb 10, 2021 6:31 pm
by pedant
Atlas wrote: ↑Wed Dec 13, 2017 2:17 am
For what it's worth (and I know someone's going to crucify me for suggesting this) a strategically-placed swipe of food-safe silicone grease (like Molykote 111) under the lip edge is often enough to ensure a perfect pour. Invisible, and you might have to reapply maybe every six months.
hahaha
i either forgot about this or just missed it completely.
i love it.
optimizing spout geometry has to be the best solution though.
Re: Tea pot spout dripping.
Posted: Wed Feb 10, 2021 7:19 pm
by pedant
nice paper
We demonstrate that surface wettability is an unexpected key factor in controlling flow separation and trickling
haha, not sure why that's unexpected
i wanted to see their electrowetting setup. turn a knob and dynamically control dribble.
apparently they have video clips, but the supplementary materials are locked up. sci-hub's not there yet!
Re: Tea pot spout dripping
Posted: Thu Feb 11, 2021 9:49 pm
by OCTO
IMO, it will surely make life much easier and more pleasant if we accept that every Yixing teapot drips. It's a BONUS whenever we come across one that doesn't drip. Agree with
@steanze and
@Bok ... modern pots don't drip as much and there are more important aspects to drool over... hahaha... Almost every single one of my vintage pot drips...
Cheers!!
Re: Tea pot spout dripping
Posted: Thu Feb 11, 2021 10:30 pm
by faj
OCTO wrote: ↑Thu Feb 11, 2021 9:49 pm
It will surely make life much easier and more pleasant if we accept that every Yixing teapot drips
Mass vaccination against COVID would help a bit, too...
When using a pot that drips, I just keep the spout pointing down after pouring and briefly touch a cloth with the tip. For me, that is the next best thing next to a drip-free utopia
.