Hello,
Today I had a problem that I couldn't understand, the recipe was the same as usual and the viscosity should be OK.
After finish grinding, I added the cacao butter the reduce the temperature, and I saw that the chocolate (white one) becoming very very thick and it was impossible to mould, so I add untempred cocao butter and it dosn't help at all, although I add around 5% and its a lot. The transition temperature to solid was high because it was thick.
One option is that the chocolate absorb water from the air, despite that it was in liquid state less time than usual (sometimes I leave him outside for 12 hours to cool down), second option in overcrystalization.
The phenomena of overcrystalization makes the chocolate very thick? why the problem dosen't solved when I add untempred cocao butter?
It's important to mention that the weather is very hot and humid.

The final result chocolate that is almost solid when moulding, bad apperance, no contraction but solid like temper chocolate.

Can someone help me what is the problem?

Thank you!

What was the temp of the chocolate?

I had two failures yesterday:

1. white chocolate that I finished grinding and add tempered solid cocoa butter and the chocolate cool to around 34C, then it keeps cooling but it became very very thick and in ~30C it was almost solid so I add untempered liquid cacao butter that should help to equalized the amount of V crystals, I add around 5-6% and it dosen't helped, the chocolate was thick and the temperature was just below 31C.

2. Two dark chocolate mixing in order to achieve different cacao percent, I used the seeding method, when the chocolate cools to 32C there were still lumps of solid inside, so I used stick blender - it eliminate the lumps, the temperature was more or less the same but it was very thick, after moulding grey sticks were forms (typical phenomena to overcrystallized chocolate).

It's important to mention that I used those formulas before and the viscosity was perfect.

I suspect that in both cases large amount of seeding and strong agitation (by hand or by the grinder) cause to over-crystallized chocolate that was impossible to work with and the liquid-solid transition was around the working temperature.

If the thickening is indeed due to overseeding (over crystallization, or over temper), simply take a hot air gun (hair dryer), and blow hot air into the mass while it's agitating to 'de-seed' it a bit until the rhehology is sufficient.    Note if you 'de-seed' it too much, you'll need to begin tempering again, and if the thickening isn't due to over temper, this method won't fix anything.

Hi Sebastian,
You have very useful answers, so thank you.
There is another aspect that I don't fully understand, it is well known that in order to properly temper you need around 1% of V crystals in working temperature in order to cause an cascade reaction during crystallization. What inhibit for the rest of the cacoa butter to form V crystals (I assume that I'm close to equilibrium)?
If there are to many lumps in low temperture (~34C in dark chocolate) so overcrystallization is unavoidable?
recently I saw this method of tempring with cacao butter:
http://www.callebaut.com/usen/techniques/tempering/tempering-with-mycryo
or other source:
https://www.google.co.il/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwjFjKiX0L3OAhXHvBoKHcMQC3oQFggkMAE&url=http%3A%2F%2Fwww.chefeddy.com%2F2010%2F03%2Ftemper-or-pre-crystallize-chocolate-using-cocoa-butter%2F&usg=AFQjCNHaQzADb6p0Vcs8Fx1rgynkP2G7IA&sig2=at-gtBT1-QlqhmS8MhB9eQ&bvm=bv.129422649,d.d2s
What do you think about this method?

Thank's!

Hi Lly - i'll admit up front i didn't read the links in detail, but rather scanned them.  To be honest, i'm not a huge fan of mycryo - sure it works, but it's an absurdly expensive way of tempering.  Shaving in tempered cocoa butter can work just fine (actually, it can be tempered chocolate, it'll do the same thing) - as long as your untempered base is of suitable temperature.  If it's too hot, you'll just melt the seed butter/chocolate and it wont' do anything but lower the temperature just a tad, perhaps.  If your base chocolate is too cool, you've already got some crystallization going on, and it'll be a hot mess.

When i'm tempering small quantities at home, i'll use the 'bring the untempered chocolate temperature to 32C and seed it with tempered chocolate' approach - but as with anything, there is more than one way to do things.  If you're working with milk chocolate, you may need a little more seed; dark chocolate (w/o AMF in it) will require a little less seed.

Edit:  The other thing to consider would be an EZ Temper unit, which is a small scale cocoa butter precrystallizer.  Works great, and uses standard cocoa butter. I'm a big fan of owning the capability.  Down side is that it's a little expensive for some.

updated by @sebastian: 08/13/16 06:53:38

AMF = Anhydrous Milk Fat (aka butter oil)

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clay - http://www.thechocolatelife.com/clay/

interesting... of course that I can shave cocoa butter and not to buy, I can try soon.

But is there still one point I don't understand: how come that you have 1% V crystals in properly tempered chocolate on working temperature, what about the remaining 99% cacao butter crystals?

I wouldn't get too hung up on the % of a certain crystal form - you have no way of measuring or controlling it that precisely, and in a batch system such as i assume you are working with, that % will continue to change over time anyway.  Focus on controlling the things you can - your temperatures, your quantities, your environment, your cooling, and your agitation - and i think you'll be far happier than trying to guess what the quantity of a crystalline structure is w/o having a x ray spectrometer on hand 8-)  If you would like to get more technical about measuring your degree of temper, i'd recommend investing in a tricor temper-meter, which works on the principle of measuring the heat of crystallization generated/released when matter converts from a liquid to a solid (or reverse).  Far less expensive than a spectrometer, much easier to use, and tells you what you need to know without requiring a PhD to interpret the results.