I have a problem with over-crystallization

[akonsu]

Hello,

I temper chocolate manually, by using a method similar to tabling. I melt chocolate in a microwave, then put the bowl with melted chocolate into another bowl with ice and cold water in it to start crystallization, and then I raise the temperature in a microwave again.

 

For the first several minutes after that the chocolate consistency is fine, but then it starts getting thick too fast.

 

I put the chocolate into a microwave for a few seconds every 2 minutes or so, to keep the temperature at the working level, but even though the temperature seems correct, I still get a lot of crystallization, it seems (is this even possible?).

 

I use white baking chocolate from Kroger (it is a grocery store in the US), this is not a couverture chocolate. I even tried adding cocoa butter to it to make it more fluid (before tempering), but the result is the same: this chocolate becomes very thick very fast. White chocolate is supposed to start hardening after a few minutes when it is spread on a surface, right? For me, it is dry to the touch after about a minute. This is too fast, so I cannot get good quality of the surface when I dip, etc. Same result for other brands of baking white chocolate. For dark chocolate this is less of a problem because temperatures are higher, but still...

 

How to manage this? If I melt extra chocolate to the degree when it has no crystals, I can add it to the tempered chocolate (this is what I heard others are doing), how much can I add to keep the mix in temper? I am afraid to add too much...

 

I would appreciate any practical advice, please.

 

konstantin

[Kerry Beal]

18 minutes ago, akonsu said:

Hello,

I temper chocolate manually, by using a method similar to tabling. I melt chocolate in a microwave, then put the bowl with melted chocolate into another bowl with ice and cold water in it to start crystallization, and then I raise the temperature in a microwave again.

 

For the first several minutes after that the chocolate consistency is fine, but then it starts getting thick too fast.

 

I put the chocolate into a microwave for a few seconds every 2 minutes or so, to keep the temperature at the working level, but even though the temperature seems correct, I still get a lot of crystallization, it seems (is this even possible?).

 

I use white baking chocolate from Kroger (it is a grocery store in the US), this is not a couverture chocolate. I even tried adding cocoa butter to it to make it more fluid (before tempering), but the result is the same: this chocolate becomes very thick very fast. White chocolate is supposed to start hardening after a few minutes when it is spread on a surface, right? For me, it is dry to the touch after about a minute. This is too fast, so I cannot get good quality of the surface when I dip, etc. Same result for other brands of baking white chocolate. For dark chocolate this is less of a problem because temperatures are higher, but still...

 

How to manage this? If I melt extra chocolate to the degree when it has no crystals, I can add it to the tempered chocolate (this is what I heard others are doing), how much can I add to keep the mix in temper? I am afraid to add too much...

 

I would appreciate any practical advice, please.

 

konstantin

Can you tell us the temperatures you are working at for the various stages?

 

And yes you can add warm untempered chocolate to the tempered chocolate to dilute out the crystals - as long as you don't exceed the working temperature. 

Edited April 11, 2019 by Kerry Beal (log)

[akonsu]

1 minute ago, Kerry Beal said:

Can you tell us the temperatures you are working at for the various stages?

For white chocolate: 45C - 26C - 29C. These are approximate, of course... For dark chocolate I use 50C - 27C (or below) - 32C. I got these from the video on tempering by Andrey Dubovik here youtube.com/watch?v=qoSCNCb62N0

 

 

[keychris]

what temperature is the chocolate when you believe it's overcrystallised? It's probably crystallising at an accelerated rate (relative to chocolate in a melting tank) simply because it's cooling. You won't stay at working temperature the whole time you're working with the chocolate, because the crystal propagation is not static, it's always happening, even at working temp, it's just that you're propagating the right crystals at that temperature. You *have* to warm it slightly to melt out a portion of those crystals and eventually you're going to have warmed it too far to stay in temper and you have to re-temper. Always take a test on a spatula or scraper and if the test sets up fine without streaks or bloom, you're still good to use the chocolate regardless of the temperature.

If you have a melting tank, you can easily demonstrate the crystal propagation: just temper your chocolate, set the temperature to 32C and walk away. In an hour it'll be a thick mass. Working temperature isn't "work forever at this temperature".

[akonsu]

2 hours ago, keychris said:

what temperature is the chocolate when you believe it's overcrystallised? It's probably crystallising at an accelerated rate (relative to chocolate in a melting tank) simply because it's cooling. You won't stay at working temperature the whole time you're working with the chocolate, because the crystal propagation is not static, it's always happening, even at working temp, it's just that you're propagating the right crystals at that temperature. You *have* to warm it slightly to melt out a portion of those crystals and eventually you're going to have warmed it too far to stay in temper and you have to re-temper. Always take a test on a spatula or scraper and if the test sets up fine without streaks or bloom, you're still good to use the chocolate regardless of the temperature.

If you have a melting tank, you can easily demonstrate the crystal propagation: just temper your chocolate, set the temperature to 32C and walk away. In an hour it'll be a thick mass. Working temperature isn't "work forever at this temperature".

 

@keychris, thank you. When I work with white chocolate, it gets over-crystallized at the working temperature (between 28C and 29C, I try to maintain this temperature always). As I understand from what you are saying, the number of crystals increase at working temperature as well, the fact that I maintain this temperature does not mean that crystallization has stopped. (I did not realize that) It is just that these crystals (that keep growing) are of a specific form, those that have higher melting point than the working temperature, that is, the "good", beta V (or what it is called) ones, right? So once in a while I have to warm the chocolate mass higher than the melting point of beta crystals (above 34C) or add warm untempered chocolate, and hope that I did not melt all of beta crystals, and check, and if the test shows that it has lost its temper, I need to re-temper. Is all this correct?

[teonzo]

Personally I would suggest you to avoid baking chocolate and use couverture. It has not much sense to go through the hassle of hand tempering and so on, then cutting costs on the chocolate. At the end of the day (considering all the time you loose for the troubles you are having) you are not saving money.

 

 

 

Teo

 

[akonsu]

@teonzo, thank you. Yes that makes sense, given that I do add cocoa butter to baking chocolate and butter is even more expensive than couverture : ) But won't I have the same problems with couverture? If I do not change the way to I things, I mean. I do not see any difference whether I use baking chocolate or something else...

[Kerry Beal]

I suspect you will have less issues with couverature / the higher cocoa butter content stays fluid longer at the same temperature.

 

[akonsu]

24 minutes ago, Kerry Beal said:

the higher cocoa butter content stays fluid longer at the same temperature

Do you know why this happens? What is the physics of this? I know this is a question for a chemist, but maybe someone knows...

[Jim D.]

Frankly I can't imagine a good-tasting white chocolate from Kroger (assuming you meant it's the store brand). You  might find Lindt at Kroger, but it's going to be expensive. As others have said, you should probably invest in some decent white couverture. You will still most likely have overtempering problems but almost certainly have a better, less-sweet taste. The thickening of white chocolate is just the way it is, and the methods you mention are the ways of dealing with it. I have found that raising the temperature gradually even as high as 90F/32C works to thin it out some, and adding untempered chocolate helps as well. If you do the latter, you can let the chocolate to be added cool to around 90F/32C and add it slowly up to one-half or even more of the volume already in the bowl. Be sure and recheck the temper.

 

Many have found Cacao Barry's Zéphyr one of the easiest whites to work with (and it's also less expensive than the Valrhona offerings). If you haven't done so, you might want to read through the threads on white chocolate (there are some on the best-tasting ones and on tempering problems).

[teonzo]

4 hours ago, akonsu said:

Do you know why this happens? What is the physics of this? I know this is a question for a chemist, but maybe someone knows...

 

Viscosity does not depend only on the cocoa butter content, but on all the ingredients. If a producer uses much less cocoa butter (compared to good quality couverture) then he needs to change the ratio of the other ingredients. All ingredients affect in different way how cocoa butter behave.

If you are using this white chocolate then it has only 6% fat, while good white couvertures are around 30%. The difference is pretty big.

The solution to your problem is pretty simple: just buy couverture, then adjust on that. You will face over-crystallization problems no matter what, but things will be really different than what you are facing now.

There are technical / scientific books aimed for the industries that explain these things, but they are really expensive ($100 or above) and are really technical (you need good notions about physics and chemistry, if you didn't attend university then those books are really hard to digest). Studying the hows and whys is always a good thing to do, so if you choose that road then you make a very fine choice. But for now it's just overkill since the only thing you need to do is buying the correct produce.

 

 

 

Teo

 

[teonzo]

I was forgetting the short explanation, I must accept I'm getting less young.

 

The big culprit to your viscosity problem is the lack of lecithin. Lecithin works properly when the ratio lecithin / cocoa butter is within a precise window. If you start from a chocolate that has 6% cocoa butter then add enough cocoa butter to reach 30%, then you are adding only cocoa butter but not lecithin. The native lecithin ratio is for a 6% cocoa butter chocolate, you are transitioning to a cocoa butter content that's 5x, so you end with a lecithin content that's 1/5 of the optimal.

This explanation is not precise, things are more complicated, it's just to give a clue.

 

 

 

Teo

 

[akonsu]

@teonzo, thank you, that was useful.

konstantin