Do they make thermometers for water kettles? I think I'm going induction.

[E_M]

So I was going to purchase a Bluestar to cook on and and electric water kettle to heat up water to the *exact* temperature for coffee or tea. But then I test drove an induction cooktop and holy cow. So, if I get induction I can ditch the electric water kettle, but is there a thermometer I can attach to it so I can monitor the water temp?

Thanks.

[sawdin]

For good thermometers, check out the Thermoworks site:
http://www.thermoworks.com/

Cook's Ilustrated did a review in January 2010 of stand-alone induction burners and their top choice was the least expensive:
Max Burton, Model Number AT6000, $125
http://www.cooksillustrated.com/equip...

Note that the stand-alone induction burners will not be as fast as those found on a full range:
"As it turns out, the power of these single burners can’t compare to a full-size induction range—the burners we tested had between 1300 to 1800 watts apiece, while a comparable induction range burner would be 3200 watts. Their power has to be limited because you plug them into an ordinary wall outlet, while a full induction range requires a special circuit."

[E_M]

Now THIS is what I mean!
http://www.cuisinart.com/products/tea...

[alanbarnes]

Oh, c'mon. Go full-on geek and plug a basic electric kettle into a PID controller...

[E_M]

No, I am willing to accept a certain margin of error. I am aiming for a 95% confidence level between 2 standard deviations.

[E_M]

The candy thermometer. I have one and was considering using that, but it has a metal clip. I need to test it with a magnet, but my concern was that the metal clip would draw the heat from the kettle and the reading would be skewed.

[E_M]

Whoa. In answer to your questions...

The minute the water hits the coffee grounds the extraction process begins. If the water is too cool the brew is weak and sourish, if it is too strong it is acidic. While the water temperate does cool the minute it leaves the heat source, well, there is a range of optimal temperatures. Also, one of the tricks to getting great coffee is to have the water go through the grinds as quickly as possible so that the water DOESN'T cool too much.

Ditto the vacuum pot. It is, for the reasons mentioned, the preferred brew method. However, at present, I am using the French press, which does make an excellent cup. Water quality, temperature, and coffee grinds go a long way to making a delectable brew.

[paulj]

I just measured the temperatures in my usual coffee rig, a small sauce pan with 12oz of water, and oven-probe type of thermometer.

- the thermometer takes up to 5sec to register. The water comes to a rolling boil when the probe still reads 208, though it ends up at 212.

- in the time that it takes to remove the pan from burner, and dump grounds in, the temperature drops to 205 (more or less). I didn't try adding grounds this time, I suspect doing so will drop the temperature further.

- with the pan just sitting on the stove (metal) without a lid, the temperature drops to 182 after 2 minutes. Using a hot pad and lid, it only drops to 192 in that time.

- with this amount of water and probe, I could not detect temperature variations within the pot.

- I did not use an induction burner this time. When I have used an induction burner, the parts of the pan not directly in contact with the water remain cool enough to touch. That might affect the temperature evolution, since heat will be lost to the cooler metal while brewing.

In summary, the temperature of your brewing water is highly variable thing, and is not easily measured at home. Even if you get it right when you take the water off the burner, it might not be perfect during the whole brewing time.

[jaykayen]

I imagine you can use the thermometers that clip to the side, like what you attach to steaming pitchers.

[paulj]

Considering how quickly boiling water cools to 200deg, I don't see much need for heating the water to exactly 200 or trying to hold it at that.

What brewing method(s) are you using. Even if you add the water at 200, how long will it stay at the temperature while steeping?

Do you have a probe thermometer with alarm, for example the kind that can be stuck in the roast in the oven and left there until the meat is done? That can be used to track the temperature of your coffee water.

[Caroline1]

All you need is a thermometer that will measure the water temp in a cup or pot. You can add cold water to cool to the temp you want or more hot to bring it up. The average candy thermometer would probably work just fine.

[c oliver]

I'm no coffee expert in the least. So you don't just bring the water to a boil? Could you just use a saucepan and measure the water temp with an infrared thermometer? BTW, I went induction a year ago and holy cow is right :) I could never go back to gas and that's saying alot as I waited along time to get gas range after leaving SF

[E_M]

No, for coffee the temp should be on average 200 degrees (or, between 198 and 205). Alton Brown's solution is to bring the water to boil and wait 30 seconds or so for it cool, which is plan B.

I'm still debating on whether to get a gas cooktop and supplementary induction, or the other way around. I really don't want to be without a flame in case I get a yen for s'mores or the power goes out. Or finally set out to master wok cooking.

[c oliver]

There's lots of good info on CH about induction. I'd check it out. Re wok, I recently read here that more than one CH uses a cast iron skillet in place of a wok not because of induction, just preference. And I have a wok that induction compatible. Anyway, check it out. Especially Politeness who's a font of info.

[Caroline1]

Induction works VERY WELL for wok cooking. Better than gas or electric and most "real" woks (as in old fashioned carbon steel that is NOT Teflon lined) are induction ready. For S'Mores, if you don't have a fireplace, you can pick up a gas hotplate at any restaurant supply or Asian market for around twenty to thirty bucks. I've had one for forty years. Whenever I need gas cooking, that's what I turn to. Go for the induction. You won't be sorry. If you ever watch Eric Ripert's "Avec Eric" on PBS, pay attention during the second half when he cooks someting... It's always on an induction cooktop. Induction has done wonders for cooling down commercial kitchens!

[E_M]

The cheapest gas hotplate I can find is this: http://www.ablekitchen.com/supplies/T... . Is this what you mean? And, this may seem like a dumb question, but...on these models, how do you hook up the gas? Wouldn't that have to be permanent, and done by installer?

[Caroline1]

I'm sorry! I should have written "butane," not "gas." Here's the kind I'm talking about:
http://tinyurl.com/4vtt4sb

[E_M]

Thanks! I will look into that, it's 100 times cheaper than the wolf double gas top.

[kaleokahu]

Car, Ipo... Should I take it from your post above that you finally got your induction cooktop? Congrats! Have you been ignoring me these past weeks because you're mastering wok cookery on induction?

Your explanations always have pith and sense... How is it that a round-bottom wok can work very well on induction?

[Caroline1]

A round bottomed wok may work better on some induction cook tops than others. The principle is the same as with any other heat source: the round bottom sits closest to the heat source and gets hottest. That's the beauty of wok cooking. You don't have to take things out of the pan when you want to slow or stop their cooking, you just push them up the side of the wok and cook the next thing in the center bottom. You can modify how close the round bottom gets to the induction unit by using a larger or smaller wok ring to establish how close the bottom of your wok sits above (or on) the unit, but those pan size sensing devices can mess things up, in which case a diffuser plate is the answer. And of course, a flat bottom wok works on ALL surfaces, induction included.

Oh, one manufacturer (Miele???) makes a built-in induction wok unit (for the mere price of an organ transplant) that has a round bottomed well for the included wok to sit in. When you're not using it to cook, your countertop has a built in salad bowl! I don't think I would pop for that very pricey unit because, unlike a regular wok on a gas burner, it brings the heat too far up the sides of the wok. That's what you get when Asian cooking appliances are designed by Euro engineers. <sigh>

No. I don't nave the induction cooktop yet. Just playing with friends and still wishing and planning. The budget for the induction keeps getting ruptured by disasters that take precedent. Today is only a mini-disaster on a personal level, but major disaster on a community level. After four days of well below freezing temperatures and heavy ice build up on all of the roads, streets and highways of the DFW Metroplex. Mother Nature has piled on a powder snow fall that was at five inches and rising at 5:00AM this morning and it's expected to keep snowing at least another five hours. There are 8 million people living in the metroplex, and an added 150,000 here for the Super Bowl and something like twelve snow plows borrowed from other cities... Do the math! <sigh> Without laughing please! This may end up being the one and ONLY Dallas Super Bowl!

[E_M]

I saw that, the built-in wok. :: laughing :: No thanks, I'm going to save in case I ever need that organ transplant.

[kaleokahu]

Car: After your playing with your friends' induction top with a rounded wok, how would you compare the diameter of the hot section at the bottom with what it is like when cooking on gas?

I cannot find anywhere solid information on how high off the Ceran deck the induction field effectively radiates for cooking. Politeness says s/he has a Japanese pan whose bottom doesn't contact the surface at all (but I gather is quite close). And it's been written many times here that the field drops off rapidly with height. I just visualize a rounded wok being an inch or more above the coil and cooktop everywhere but a very small bilge area. Maybe it's explainable in terms of the oil being heated by convection--maybe you don't really need the whole wok bottom being licked by flame. But if much of the wok is being heated by induction more than an inch above the Ceran, I have concerns about utensils and burns.

[paulj]

The coil on the induction burner that I took apart recently has an inner diameter of 1 1/2", and outer of 7", so it looks almost like a solid disk of copper wire. I believe the magnetic field lines from that would be drawn as elongate ovals wrapped around that ring. The field from a point source does drop off with the square of the distance (1/4 strength at 2x the distance), but a broader source like this focuses the energy at right angles to the ring. So the energy probably does not drop as fast as for the point source.

I don't recall if I every tested my wok on that burner. I was surprised, though, at how well a stainless steel mixing bowl worked for boiling water. I surprised that it worked at all since it was not magnetic and labeled 18/10. But its flat base was only 3 1/2" in diameter, and the sides slope up faster than a wok. I did not try to figure out where the heat was generated, but it probably was more than the flat bottom.

So, be wary of intuitions when imagining the magnetic field from an induction burner.

[Caroline1]

There is no "standard height" that a wok sits above anything. It is determined by the aparatus the wok is placed upon while cooking. Some special wok charcoal or gas burners set the wok low into the fire while home woks are usuallly set in a "wok ring". They are larger diameter on one side than the other and are reversible. For example, when I am cooking on a gas burner with mine, I put the widest diameter down, which directs the heat up to the narrower end of the wok ring that is holding the wok. This has a chimney effect. Conversely, when I'm cooking on an electric burner, I reverse the wok ring so the wok sits much lower in the ring and closer to the heat source. This is the way I would use it on an induction burner, but induction burners do apparently vary from manufacturer to manufacturer as to distance the magnetic waves will travel to reach a ferrous metal AND/OR vary on how large or small the diameter of a vessel must be to be recognized by the sensor. As I said, a diffuser may be the best bet with woks on some induction cook tops.

[Chemicalkinetics]

I do want to reiterate E_M's point that many people believe coffee (as well as tea) should be brewed/steeped at temperature below boiling water (below 100oC /212oF). In fact, the more delicate the tea the lower the temperature. (Delicate does not mean better).

Now, I am not really that into tea nor coffee, so I don't follow these rules, but they are certainly well-recognized.

http://coffeetea.about.com/od/teabrewing/a/teatemp.htm
http://www.2basnob.com/brewing-tea.html

[paulj]

But as discussed in sous vide threads, do you know if all of the water is at the target temperature? Water at a rolling boil will all be close to 212, but if your target is 200, there might be a strong temperature gradient from top to bottom. The bottom is hot enough to form bubbles, but water closer to the surface is too cool to support them. Notice how the bubble pattern changes when you stir an open pot of water before it boils.

In addition, the moment you pour the water into a tea pot or French press you change its temperature. There would be less of change if you brewed the coffee in the same pan that you boiled the water in, but regular brewing will stain that pan (that's how I do it).

[Chemicalkinetics]

No idea. I am not really into coffee or tea, let's alone an expert. You made excellent points about the temperature variation. Of course, do coffee and tea taste better at these temperature ranges is another question all together too.

[Politeness]

E_M: "for coffee the temp should be on average 200 degrees (or, between 198 and 205). Alton Brown's solution is to bring the water to boil and wait 30 seconds or so for it cool, which is plan B."

Alton Brown is on the low side. At sea level, as close to boiling as you can get -- but, yes, short of boiling itself -- is the ideal for coffee brewing. Plan A+ to achieve that temperature is to brew by the vacuum pot method, which "automatically" gets the water to the grounds at the ideal temperature for brewing without the need for either thermometers or timers.

[Caroline1]

Or if you want to be super lazy, a super-automatic espresso machine will do it ALL for you! I LOVE my Jura Capresso! But I do have my Cona for back up! '-)

[paulj]

More likely than not, the induction cooktop (or stand alone hotplate), has a temperature sensor under the cooktop surface. This senses, in a rough sense, the temperature of the pan, and hence the contents of the pan. This isn't quite as good as using a temperature probe in the water itself. Another limitation to the builtin temperature control is that it may have big steps, e.g. 140, 180, 212, .... I am more familiar with what induction hotplates offer than $1000+ stove tops.