My choc thermometer

[Lior]

Talk about getting confused and under confident! I decided to experiment different tempering methods with my Mol d"Art melters.

Here:

1. Put tempered milk chocolate into melter, set the thermostat at 30 C and wait over night.

2. Put tempered milk chocolate into melter, set at 45 C to melt, then set to 30+ and leave a few hours to form a "crust"

3. Put tempered milk chocolate into melter, set at 45 C to melt, then set to 30 C, add seed, mix etc until tempered

Results and problems:

1. The room temperature here is 23 C daytime and 17 C nighttime. The chocolate did not melt much. I left it for three nights till it was soft enough to mix. Even after raising the temp in 0.5 increments and waiting patiently it was extremely viscous and could not be used. I also could not really figure out what is 0.5 degrees because the thermostat is analogue not digital. So here I tried using my choc thermometer and it showed up to 3 degrees different temp reading...I then tried my caramel thermometer and it showed a third different reading! I began getting confused about the red light on the melter-anyone who can expalin why it goes on and off- Iwill be grateful. It goes on when it is set at 45 before it is near 45 and then clicks off. What am I not getting??

2. Took much longer than two hours and in the end same as 1 above-viscous and impossible to use - even when I tried the hair dryer method. Again I had to rely on my thermometer which may not be reliable. Too bad the melter does not have a digital control!

3. I got tempered chocolate of course. But all three readings-the two thermometrsand the melter's thermostat all had different readings, none were what I expected! The thermometrs read 33.6, 32.8 and the melte was set at 30.

Any comments or advice? Ergh!!! Thanks for reading this long and boring account!!

[John DePaula]

I recently did an experiment with 4 different thermometers in my kitchen. I stuck all 4 in a pot of boiling water. Now we all know that they should have read exactly 100C, right?

Here are the results:

Analog Lab Thermometer: 102C

Taylor Analog Candy Thermometer: 97C

CDN Digital Instant Read Thermo: 91C

Polder Digital Instant Read Thermo: 100C

As you can see, they were all markedly different. And the results will probably vary for a different temperature range.

As for why the melter goes on and off like it does, it has to do with hysteresis. In order to maintain a particular temperature accurately, you have to have hysteresis. That means, for example, that if the control circuitry turns on the heating element at 30C, then it won't turn it off until the temperature reaches 32C. And then it won't come back on until the temp drops below 30C again. you need hysteresis to keep the unit from cycling on/off rapidly when you reach your setpoint temp of, say, 31C. The system, the mass of chocolate, needs time to respond to the nudge of heat.

The temperature dial on the Mol d'arts are just a rough estimate of the true temperature of the chocolate. And really that's enough. You don't have to use a thermometer to temper chocolate. Just adjust the dial to keep it at a workable temperature.

[alanamoana]

To add to what John mentioned: the light is on when it is heating and goes off when it is not heating.

Lior, are you covering the chocolate during the melting process? It should be covered so that you don't lose too much heat to the atmosphere. Also so that you don't get a ton of humidity in your chocolate (thus affecting your viscosity).

[David J.]

1. Put tempered milk chocolate into melter, set the thermostat at 30 C and wait over night.

Once you figure out what the dial setting is when you are really at 30 C this might work, though this is a really slow method and would require stirring several times as the chocolate wouldn't be evenly heated. An additonal problem is that you would have far more crystals than you want and it would be very viscous. That would necessitate bumping up the heat either through the melter or via an external source such as a heat gun for a time to melt out some of the exess crystals. Remember, it's time, temperature, and movement. You would hold the temperature up above the melting point for the crystals long enought to melt out the excess without melting all of them. That's a matter of feel.

2. Put tempered milk chocolate into melter, set at 45 C to melt, then set to 30+ and leave a few hours to form a "crust"

Not sure exactly what happened here, but you may have formed too many crystals again, possibly undesirable types as well depending on the true temperature. I've never tried this deliberately but had it happen when I left a melter on overnight and the crystalization ran away. I just melted out the excess and it worked fine.

3. Put tempered milk chocolate into melter, set at 45 C to melt, then set to 30 C, add seed, mix etc until tempered

That's the typical way I run my melters. Set it to melt everything completely overnight and stir it the next day to be sure everything is melted out before adding seed. I set it to what I guess is the correct temp and let it cool a bit before seeding so I don't have to add as much. Don't worry too much about the reading on your thermometer as long as it's close (calibrating your thermometer is a good idea too) and the viscosity feels/looks right. As always check the temper with on a piece of baking paper before using. I adjust the dial to maintain the correct temperature, but even then if it sits too long the crystalization will start to run away and I will have to melt some of them out with the heat gun to keep it flowing well. If I think I may have taken it too far I'll recheck the temper before using.

[mrose]

You could check the Polder at the low end by putting it in water with ice cubes & see if it accurately reads 0c. This would assure you that it is a reading correctly.

Put water in the Mol d"Art & set it for 30c & 45c, the check the temp with the Polder. You would then know what temp the dial setting actually gives you.

Edited November 15, 2007 by mrose (log)

[Lior]

Thank you everyone. I temper by hand no problem and I have lost some of my confidence with these melters! I just need to get to know them better I suppose. I laughed at the boiling water temp check! So brilliantly simple - I am going to do it now! I do cover the chocolate with the lids as it is humid here. I appreciate the explanation about the light going on and off.

A while back I mentioned that I am buying an upright beverage refrigerator, with a glass double door-low expense so low risk- cost about 600$. I had a technician put a new temperature control in-he just connected the appropriate wires to the new control unit and set it at 14-17 C. So the temp is right. That was no problem at all.

Now I need a dehumidifying accessory, although I was hoping the humidity would be alright, it isn't. Does anyone know about such a unit? I figure that for the price it is still a lot less than the fancy display fridges for chocolate and bigger. If the chocolates are in a well closed container it is okay, but I want to have it right if they are out in the open.

Thanks so much to all.

[Lior]

hello. I wanted to calibrate my thermometers by the boiling water method, but then remembered from way back when, that the boiling point changes according to altitude, so I need to find out what the B.P. is here, about 150m-200 above sea level... Anyone know?

[Anna N]

hello. I wanted to calibrate my thermometers by the boiling water method, but then remembered from way back when, that the boiling point changes according to altitude, so I need to find out what the B.P. is here, about 150m-200 above sea level... Anyone know?

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I doubt that your altitude would affect it any measurable way (except by very precise scientific instruments). Here's the Crisco site that suggests a much higher altitude before one really needs to make any adjustments in baking.

[Lior]

Hi thanks, but I want to calibrate my thermometer and if my water boils at 99.4 for example, then I can figure out my thermometer, I know it is not a big difference, but I want to try anyway.

Thanks anyhow!

[Kerry Beal]

Here is a calculator.

[Lior]

I LOVE you!!! Thanks!!!

[mrose]

I LOVE you!!! Thanks!!!

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Lior

Since you don't have the exact altitude the boiling point will only be an approximation anyway. Also according to the formula, it would change everytime you work since it asks for the barometric pressure. You also have to account for the accuracy (+/- %) of thermometer & gauges on all the equipment used. It seems like a lot of work for maybe 1/2 a degree varience. I'm impressed by your tenacity.

Mark

[Lior]

Well just in case someone out there is curious... I was correct in guessing 99.4 C for water's B.P. According to the calculator that Kerry so kindly gave, my B.P. for water should be 99.4. So I went ahead and boiled some water.

One thermometer read 99.3 and the other, the one I usually use and thought to be more accurate, read 101.8!!

Today I used my melters without the thermometer and with milk chocolate. I kept checking a sample for temper until I thought I got it right. The chocolate seems okay, although the ambient temp is 24 C, so that may be why it took so long to harden.

On the fridge note, the thermostat is also not accurate... and tonight the technician is coming to see what can be done about the humidity.

thanks!

[John DePaula]

One thing that you should be aware of is that thermocouples are accurate only over a fairly narrow range.

What that means is that your thermometer may be accurate to +/- 0.5ºC over the range of, say, 90ºC - 110ºC.

But if your working range for chocolate is 25ºC - 55ºC, the variance may well be different. Could me more, could be less.

So, calibrating your thermometer for boiling water may not actually be helpful since you're working in a different range with chocolate.

Sorry.

[Lior]

Oh! you are introducing me to many curious things!! Now I will have to work this one out!! Any leads?

Edited November 18, 2007 by Lior (log)

[Anna N]

Oh! you are introducing me to many curious things!! Now I will have to work this one out!! Any leads?

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I think it gets even worse! How did you determine your elevation? There appears to be no standard way of determining elevation for a city/town/village - was it based on an average for the city, a particular land mark, or some other data? And where are you in relation to whatever point determined your area's elevation?

I think it's fun to perform such experiments and try to reach a certain level of accuracy but in the final analysis I don't believe we have the tools at our disposal to do anything but make a guesstimate.

Still I love the process and would not by any means discourage you from continuing to strive for accuracy!

For myself, I think I would work backwards! Hand temper your chocolate and then take its temperature - whatever it's temperature on that particular thermometer will work and should be your target temperature. That will work - for a time - but all thermometers eventually "slip".

Edited to add:

You might also want to check both thermometers in ice water to see if they differ by the same amount.

Edited November 18, 2007 by Anna N (log)

[John DePaula]

Personally, I wouldn't worry quite so much about the thermometer issue. I think it's more important for sugar work, by far.

For chocolate work, you have so much variability because of humidity and the amount of beta-crystals, etc. You'll develop an eye and a feel for chocolate so eventually you won't need to rely on the thermometer so much.

Happy Tempering!

And remember: Making Chocolate is Making Fun!

[Lior]

Lior

Since you don't have the exact altitude the boiling point will only be an approximation anyway. Also according to the formula, it would change everytime you work since it asks for the barometric pressure. You also have to account for the accuracy (+/- %) of thermometer & gauges on all the equipment used. It seems like a lot of work for maybe 1/2 a degree varience. I'm impressed by your tenacity.

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Hi! Well I am stubborn about getting things just right, I know... I do know my altitude and I realize the changing factors issue of course, but I had no idea where my thermometer stands and wanted to know more or less how far off it was. I have tempered chocolate by hand for two years, with no problems. As of late I am having trouble with the Callebaut milk choc. I usually use Fruibel. And my melters are new and I wanted to use various methods for experimentation, because I want to be able to have that know - how at the snap of a finger-to really get to know the chocolate. Well I guess I can deal with it from here on, thanks to all for the ideas, input and direction.