When I first saw the Medelco glass whistling kettle, I was shocked. I mean - boil water in a glass container? Isn't that nuts? Then I remembered the many chemistry and science experiments I did in school where I boiled water in glass beakers using bunsen burners and melted various chemical crystals inside glass test tubes. Using a glass kettle slowly started to make sense.
The Medelco whistling kettle is listed at $15 although you can often buy it for under $10, especially from online retailers. I am not surprised at the rather low price. After all, glass is made from sand, one of the cheapest and most common substances on Earth. This is the reason why even the cheapest metal stainless steel kettles cost more. There is currently a shortage of iron, steel and the various special substances that turn iron into steel and steel into stainless steel.
While a glass whistling kettle is undoubtedly not as rugged as a metal kettle, do not let the fact that the Medelco kettle is made from glass fool you. The glass is German-made laboratory-quality borosilicate glass, and is a very tough glass. You can safely wash this glass kettle in a dishwasher.
Someone more used to metal cookware may be a bit squeamish about putting the Medelco glass whistling kettle on top of a stove. However, anyone who has used Corning cookware made from glass or anyone who has seen their friends who majored in Chemistry make coffee in glass beakers heated by a bunsen burner know that it is perfectly alright to place the Medelco kettle on top of an open flame. It is also fine to heat the Medelco whistling kettle on an electric stove, albeit you need to place the included trivet heat diffuser between the glass kettle and the burner on the stove.
You can boil 48-ounces of water in this whistling kettle, enough to make 12 cups of coffee or tea if measured using the standard 4-ounce sized European tea cups or 6 cups of coffee/tea if measured using American-sized 8-ounce cups. This is typically enough for even the largest french press.
When you first take the Medelco whistling kettle out of its box, you should see a piece of metal shaped like a three leaf clover inside the kettle. Take it out - this is the trivet (heat diffuser) which you need to use with an electric stove. This trivet is meant to go between the kettle and the burner on your stove (even the newer glass-topped electric stoves). However, it is not used for gas stoves. Also, do not leave it inside the kettle, as some customers have done. The trivet will rust.
The plastic lid needs to be firmly (but not tightly) seated with a good seal so that the steam produced when the water boils will be forced through the whistle in the lid to make the whistling sound. You will only hear a whistling sound from the Medelco glass kettle once the water boils strongly. There will not be any whistling when the water is just coming to a boil.
Always use a small burner for this glass whistling kettle (regardless of whether you are using a gas or electric stove). Make sure the outside of the kettle is clean and dry. In general, start with a low flame for a few minutes to warm up the glass before slowly turning up the heat through medium up to medium-high. This lets the glass expand slowly and evenly and helps to prevent cracking.
If you have to use a large burner (on an electric stove), offset the kettle to one side so that the handle is out of the line of heat. Otherwise the handle will heat up and become too hot to touch.
In addition, if using a gas stove, do not use such a high flame that it licks the plastic parts of the kettle (like the handle). While this is common sense, there have been customers who complained that the handles of their Medelco kettle melted.
Like any whistling kettle, turn off the flame/heat once you hear the whistle. Do not leave the kettle on the stove or the water may boil dry and crack the kettle. The plastic parts may also melt, exactly the same as the plastic parts on any metal kettle.
When the water boils, place the kettle on a pot holder or dry towel. Do not place it on a cold burner or your kitchen counter or the glass may contract too quickly and crack.
For dedicated tea and coffee drinkers, the taste of the water they use is very important. Thus glass kettles like the Medelco whistling kettle have a very important quality - they do not contaminate the boiled water with any metallic or plastic/Teflon smell. Granted that most of us will not notice anything, but these connoisseurs are very fussy people.
This is a glass kettle, so it does not rust. Even the finest quality stainless steel kettle will eventually rust, and most kettles are not made from the best stainless steel. Which means you never need to worry about drinking rust. You can also clean it with strong vinegar, unlike metal kettles. If you have small hands, you can reach inside the body of the Medelco whistling kettle with a scrub pad to clean it, if not you can use a bottle brush.
The transparent glass body makes it possible to see how much water is inside it, which is convenient. Unlike normal metal whistling kettles, you do not need to lift the lid to peer into the kettle to see if you need to refill it. You can also see the water boiling, which can be quite interesting especially for children. Apart from this, you can also see when the kettle is dirty (for example from the residue of hard water) so you know when to do a more intensive cleaning with vinegar.
Most metal kettles are made of many different parts soldered together, so there is always the risk of leaks or some part falling apart (especially the spout or even the bottom of the kettle). The Medelco glass whistling kettle is made of one whole piece of glass so it does not have this problem.
Although it is made from glass, the glass is thick enough to NOT feel fragile yet it is still thin enough to let the water inside heat up quickly. Overall, the entire kettle is quite solidly built.
At $10 to $15, this whistling kettle is cheap. Many people buy two or three at a time and do not think twice about replacing it when it breaks. This is unlike many metal kettles which cost $30 to $100 or even more.
While the Medelco glass whistling kettle is thermal-shock resistant, it is not pyrex. If you pour cold water in it while it is still hot, or if you place it on top of a cold stove while it is still hot (for example after you boil your water), it may crack or break. Similarly, if you pour hot water into it when it is cold, it may also crack. However, these are just basic common sense when using any kind of glass cookware.
The handle of this whistling kettle is placed a bit close to the glass body, so some people feel an uncomfortable heat when holding the kettle. If this is the case for you, just wear a glove or mitt.
You have to remove the lid of the whistling kettle before you pour water from it. This is a bit different from old metal whistling kettles where you flip open the cover at the end of the spout. However, there is a handle on the lid so lifting it off is easy.
It seems that the plastic and metal parts (the lid and handle) of the Medelco whistling kettle are made in the US, but the quality control is not as consistent as the glass body of the kettle. Many customers have said that the whistling sound is not loud, and some have complained that it is very soft. Also, the plastic lid can be a bit fragile - some plastic lids have broken in transit while the glass kettle itself was unharmed. There have also been complaints that the handle sometimes becomes wobbly. Fortunately replacement parts for the kettle are easy to buy direct from Medelco. Just check their website for details.
Like any other stove-top kettle, the Medelco whistling kettle will not boil water as quickly as a powerful 1500-watt or 1800-watt electric tea kettle, but it is still faster than the cheap flimsy China-made stove-top kettles which rust easily.
The Medelco glass whistling kettle is a fine product at a very affordable (low) price. As it is made of glass, it needs to be treated and used like other types of glass cookware. It cannot be treated like the more common metal cookware you find in most homes. Due to its different design, it also does not pour water like traditional kettles, which may be discomfiting to some people.