Don't handle when hot!

January 4, 2006 12:41 PM

Why aren't coffee pots made from Pyrex?

I don't drink coffee, so I have no experience with these things. I got my girlfriend quite a nice coffeemaker for Christmas, and printed on the pot itself (as well as all throughout the documentation) were several warnings about the fragile nature of the glass used for the pot - all of which led me to think that the pot is so fragile that it almost can't stand up to normal use.

Is there something about coffee that renders more durable glass products (like Pyrex or safety glass) unusable as coffee pots? Is it purely a price issue? It seems silly to make coffee pots out of glass that's so fragile that there need to be about 15 warnings about proper handling on the thing.

posted by pdb to food & drink (20 comments total)

I think more than a concern over the general fragileness and ease of breakage is the fact that it's intended purpose is to be full of hot liquid. Can you hear the collective lawsuit sigh? I mean, slam a pot of coffee down on the counter and then be surprised when it breaks and burns you! Get! Millions! of! Dollars!

These multitudes of warnings woudl seem to offer a level of protection to the manufacturers of coffee machines.
posted by bilabial at 12:50 PM on January 4, 2006

I think the warnings are a load of crap anyway. I mishandle my coffee pot (with warnings), throw it in the dishwasher, and accidentally leave the pot turned on with an empty carafe all the time. It hasn't exploded in my face yet.
posted by catfood at 12:59 PM on January 4, 2006

Apparently, they used to be. A google image search for ""Pyrex coffee pot" turns up tons of antiques and collector's items. My best guess would be that a 10-cup Pyrex coffee pot would be pretty heavy when full -- and therefore more prone to dropping -- than a lightweight glass pot.

Also, Pyrex isn't shatterproof, especially when it's hot. I learned that the hard way when a hot pie plate slipped out of my hands one day and shattered into fine shards that were actually harder to clean up than regular glass.

I do agree that the warnings are probably more for reasons of lawsuit prevention than actual necessity. In 15 or so years of coffee drinking, I can't recall a broken pot.
posted by boomchicka at 1:02 PM on January 4, 2006

Pyrex is not so much durable as resistant to breaking under high heat. Coffee, on the other hand, suffers in taste when it is boiled after brewing. Therefore I see little need for a Pyrex coffee pot, although isn't that what your standard Mr Coffee globes are made of?
posted by Rash at 1:03 PM on January 4, 2006

All the above is true, and I think coffee pots may effectively be made out of Pyrex (but perhaps a non-trademarked generic version).

The one thing that hasn't been mentioned yet is that coffee pots are exposed to extremes of heat which makes glass less stable, another reasonfor the warnings. Put your pot on the burner with no liquid in it for a half hour then drop several ice cubes into it and see if it doesn't explode.
posted by Doohickie at 1:04 PM on January 4, 2006

Pyrex is thicker. Perhaps the thin glass heats up faster, and cools the coffee down less, and so you can a nice hot cup as soon as it is brewed.
posted by carter at 1:05 PM on January 4, 2006

Another Pyrex anecdote: At one point an ex-girlfriend left a Pyrex lid on a stove burner (well, she turned on the wrong burner) it heated up to a rather extreme degree, and she didn't realize this. She touched it with a wet hand and the damned thing exploded! She was unhurt, but we found shards as far away as 12 feet, all of which were incredibly sharp.
posted by Kickstart70 at 1:12 PM on January 4, 2006

If you really want durable, Cuisinart makes a drip coffeepot with a stainless steel pot.
posted by smackfu at 1:17 PM on January 4, 2006

all of which led me to think that the pot is so fragile that it almost can't stand up to normal use

Yet empirically, coffeemakers do stand up to normal use, warnings notwithstanding. It is a serious pain in the ass to get a replacement carafe from the manufacturer, though, so a bunch of "be careful, klutz!" warnings fit in nicely. And any glass hot thing is going to weaken easily with scratches and chips, so keeping it pristine is pretty important.

That said, were I going to buy a coffeemaker today, it'd have an insulated carafe instead of a glass pot and a burner. Solves this problem and the burned-coffee problem all at once!
posted by mendel at 1:19 PM on January 4, 2006

For what it's worth, I've got a french press in front of me that's made out of Pyrex. It is, however, imported from Italy.
posted by SweetJesus at 1:33 PM on January 4, 2006

...I've got a french press in front of me that's made out of Pyrex. It is, however, imported from Italy.

I have a good but common American French presspot made from Pyrex.

Off-topic: I think things taste better in hard glass (or, for example, well-glazed ceramic) than the opposite. I'm very aware of the taste of liquids related to their drinking vessels. Plastic? Ugh.
posted by Shane at 1:36 PM on January 4, 2006

Pyrex is a trademark (Dow-Corning) for a particular recipe of borosilicate glass, glass doped with boron rather than sodium. Other companies make very similar products, Kimax by Kimble, for example. Pyrex has been out of patent for quite a while so borosilicates are fairly common now. They're a little more expensive to make than regular sodium glass (window glass), but are significantly tougher and resistant to thermal shock than regular sodium glasses. To directly answer the question, almost all glass cookware is made out of borosilicate, whether labelled Pyrex or not. If yours says Pyrex, it was made by Corning, if not, it came from someone else.

Pyrex is not magic though. You can still thermally shock it, like Kickstart's example above, it's just a little harder to do than with regular glass. Since Pyrex is just a recipe, glass made from it can be a wide variety of sizes and shapes. It's not necessarily thicker.
posted by bonehead at 1:48 PM on January 4, 2006

Shane:

Do you mean the taste of the drinking vessal in your mouth alongside the liquid, or that if a liquid was poured into a certain type of vessal before being poured into your cup, the vessal would have altered the flavour enough to show up in a double-blind trial?

I'm assuming you meant the former, because I get that too, (though it doesn't bother me or give rise to much in the way of preferences) but I'm curious if you instead meant that the vessal permanently alters the flavour.
posted by -harlequin- at 3:04 PM on January 4, 2006

Like the above posters, I'm sure it's just a mix of CYA, not having to pay Corning the licensing fee for "Pyrex", and that the printed Pyrex brand doesn't move product the way it used to.
posted by junesix at 3:16 PM on January 4, 2006

That said, were I going to buy a coffeemaker today, it'd have an insulated carafe instead of a glass pot and a burner. Solves this problem and the burned-coffee problem all at once!

Best answer.

Your traditional office/truckstop/7-11 style, glass-jug-sitting-for-countless-hours-on-a-hot-burner style coffee carafe is a poor, poor design for a few very important reasons:

1. Most importantly, the coffee tastes like crap compared to insulated carafes since it's being constantly heated after it's been "made".


2. Exposed glass can break (as the initial question points out). Insulated carafes have glass, too, it's just on the inside--so I don't know why anyone would suggest "plastic-tasting" coffee since the only plastic is on the outside of the jug.


3. Glass pots pour for shit. This is only my personal experience, but every single time I fill up a coffee maker with a glass pot, the lip never fully constrains the pouring action, and I inevitably wind up with some water spilling over the sides.

The single largest drawback of insulated carafes is that they hold less coffee. By design, they need to hold the insulating glass container, a layer of trapped air, and the plastic surrounding the entire vessel. So all that volume going to insulation instead of coffee.
posted by Civil_Disobedient at 6:43 PM on January 4, 2006

I agree with you C_D, carafes are nice. With a few exceptions though, they look like crap, either being junky plastic or this odious "industrial" stainless look that is all the rage with "professional" amateurs right now. Our kids are going to make as much fun of this "style" as we do of the seventies avacado and gold. Does anyone make a french press carafe that one wouldn't feel embarassed bringing to table? Anything this attractive (made from borosilicate glass, btw)?
posted by bonehead at 7:28 PM on January 4, 2006

You can find French presses like that at just about any coffee place that doesn't end in "Donuts". If you want high-end, Williams-Sonoma sells the larger kind for about $40.
posted by Civil_Disobedient at 7:39 PM on January 4, 2006

Nononono (though I appreciate your effort). I meant carafe french presses. All too often they look like this. Uuuuugly!
posted by bonehead at 7:51 PM on January 4, 2006

Most importantly, the coffee tastes like crap compared to insulated carafes since it's being constantly heated after it's been "made".

I'm quite used to that, and at this point, I don't really like fresh-brewed coffee anymore. I prefer the "been warming for a while" flavor.

Glass pots pour for shit. This is only my personal experience, but every single time I fill up a coffee maker with a glass pot, the lip never fully constrains the pouring action, and I inevitably wind up with some water spilling over the sides.

Patience, grasshopper! I never have that problem.
posted by Doohickie at 7:50 PM on January 5, 2006

Nononono (though I appreciate your effort). I meant carafe french presses. All too often they look like this. Uuuuugly!

For attractive and well-made French presses, carafe or otherwise, I turn to Bodum first. The Columbia is still stainless steel, but it's curvy and mirror-finish instead of brushed. Personally, I'd probably get a Chambord or Eileen for the brewing, and transfer it to a thermal carafe for serving, which would leave me with a French press ready to prepare the next pot of coffee before this one runs out.
posted by mendel at 9:47 PM on January 6, 2006