Ask the Alchemist #338
I have been really struggling lately with white chocolate. It gets too thick to work with when I finished grinding it. My recipe has been 500g cocoa butter, 489g coconut sugar, 190g milk powder. I grind it in melangeur for 48 hours, temperature reached 108F. I tried seeded method of tempering and another time cool bath. By the time it gets close to 88-90 F it starts thickening. At 84-86F it gets impossible to work with it. Why is that happening?
And there you go....a completely true and NOT helpful answer.
So much of chocolate making is being a problem solver. This is true for any type of making whether you be butcher or baker or candlestick maker. In the past I have talked about #FAFO and to some degree that applies here but it is slightly different. In #FAFO you are usually seeing if you can do something. Can I add honey to chocolate? Can I add cilantro? What happens if I enrobe dried smoked duck head? Is cold smoked duck head better than hot smoked duck head with my 74.18% dark chocolate or should I use 62.68% dark chocolate?
In all those cases the answer is #FAFO (I prefer hot smoked duck head with 69% dark chocolate).
On the other hand, when something is going wrong, f’ing around often isn’t what you should do....at least at first. Instead you should put on your sleuthing hat and see if you can come up with some things that might be going on and then duck around and test them.
So the chocolate is too thick. What can cause chocolate to be thick? If you put that into Oracle G you’ll quickly find that water is the most common culprit. Did you introduce it when you were melting the chocolate? Was it over a double boiler? That could certainly add water.
I do see it seems you are cooling right from the melanger so it probably isn’t steam from melting the chocolate. But just in case you are melting, you have checked and are sure you didn’t add any water to your chocolate. Where else could water come from? Could one of the ingredients have too much moisture?
There are only 3 ingredients here. Get your magnifying glass out and think about each one.
Could it be the cocoa butter? Nope, that is a pure fat and water isn’t going to find its way there.
There is milk powder. Most likely this isn’t it. Although not impossible I’ve never seen milk powder pick up moisture.
How about the sugar? For regular refined sugars there is little chance of moisture getting in there. Hrm...but this one is coconut sugar. I’ve used some coconut sugars and they were just fine. They met the crawl test. When poured out they did not crawl like brown sugar does but poured smooth and easy like grains of sand. I have also seen coconut sugar come less refined and it stuck together and crawled and needed to be dried before using. That amount of moisture might not totally seize the chocolate but it could well cause that premature thickening.
What else might be causing your premature thickening if it isn’t the ingredients or water contamination?
Maybe it is the amount of ingredients you are using. Did you verify the recipe has enough fat in it? Do you know what the guidelines are for how much fat you need (minimum 35%)? How do you find that out? A good place would probably be my white chocolate recipe.
Chocolate Alchemy’s White Chocolate recipe
16 oz Cocoa butter (36.4%)
14 oz Whole milk powder (31.8%)
14 oz sugar (31.8%)
Premature thickening White Chocolate
500 g Cocoa butter (42.4%)
489 g Coconut sugar (41.5%)
190 g Milk powder (16.1%)
At a quick glance it is a pretty different recipe but also the fat content in the troublesome recipe is higher than one that supposedly works so there is probably no issue there.
All those previous items should be your go to checklist for diagnosing problems.
What else could be wrong?
These next couple I only learned over years of diagnosing issues and having to dive deeper when the solution was not staring me in the face.
I remind you the issue is that the chocolate is getting thicker at 88-90 F and very thick at 84-86 F. That just isn’t right, right? Here is an interesting proposition.
What if there is nothing wrong with the chocolate?
What if you only think there is something wrong because you have made a bad assumption? How do you know the temperature was 88-90 F? Sure, I believe you that the thermometer said that...but how do you know? With over 20 years in the lab and 40 years making things I can’t tell you how often I thought there the issue was one thing and it turned out the issue was bad data. I spent probably 25% of my time in the lab either calibrating or making sure my instruments were calibrated.
Just last month I roasted a new sample bean and the resulting chocolate tasted WAY over roasted. Instead of thinking it was a bad bean or that I had messed up the roast I immediately went to the thermometer I use in my sample roaster and tested it. Water does not boil at 197 F and does not freeze at 27 F. Shit, it was reading 15 F too low at the top end and 5 F low at the bottom end. That means I roasted at least 15 F too hot and missed all my critical benchmarks (212, 232 and EOR). A quick change of batteries later and suddenly water was boiling at 211 (nothing is perfect) and freezing at 31 F (close enough).
So I ask again, how do you know your thermometer was good? Mine was good for 18 months and then it wasn’t. It worked the day before and the next day it didn’t. Question your assumptions.
But again, let’s go ahead and think about what else could be wrong.
At this point the only other thing that comes to mind for me is this occasional behavior I’ve seen in milk chocolates.
Do you know how hair curlers work? Hair is made of protein and proteins are made of amino acids. Cysteine is an amino acid with sulfur groups that when heated up form loose bonds with each other. Hair contains Cysteine and when you wrap it up and apply heat, it makes some of those loose sulfur bonds and you end up with glorious curls
Eventually these weak bonds break on their own but if you brush them out, that can also break them.
Alchemist, did you have a stroke? We were talking about chocolate and now you are talking about hair. eewwwww.Guess what else has protein in it? You got it. Milk. And one guess which amino acid is in milk protein? Good job, you got it. Cysteine. At one point I had a perfectly good milk chocolate and I let it set up.
I go back and melt it and it is thick.
I stir it and it is thick.
I toss it back in the melanger for 5 minutes and like magic it is flowing just great. I brushed it out as it were.
So now what do we do??
Oh wait....I thought of one more thing. Although it is difficult to do, it is not impossible. If chocolate is refined too much it can cause an increase in viscosity. It could be that you refined too much. 48 hours is usually just fine for the kilogram of chocolate that is being made but it is worth mentioning. You can’t fix it but at the moment we are just identifying what the issue could be.
At this point we have identified some things that could be causes the issue.
Water in the chocolate from:
milk powder
sugar
double boiler
The recipe needs adjusting
The thermometer calibration is off
The chocolate was allowed to set up and form cysteine bonds
The chocolate was over refined.
With that in place, NOW is the time to #FAFO. This is testing your hypothesis.
Testing the water theory
On a new batch of chocolate:
Dry the milk powder and sugar in the oven at 150-170 F for 3-4 hours.
Temper without using water baths, either hot or cold.
Is the recipe the cause? Not enough fat is should be the only concern.
Add 5-10% more cocoa butter to the chocolate (in the melanger) and see if it thins out and behaves.
Since I’m sure you are on top of this now, you can go ahead and test that cysteine idea by running the chocolate in the melanger for 5-10 minutes before adding the butter and see if it suddenly thins out.
Over refining.
There is nothing you can really do on the chocolate you have in hand. You can’t unring that bell. Try refining 24-36 hours and see how it behaves.
You can also try adding about 0.4% lecithin to the premature thickened chocolate. If that suddenly helps you are pretty much guaranteed the issue was water. If it doesn’t help it at all, it is something else.
Thermometer calibration.
I would start here as it is the simplest to do.
Boil some water and verify it is reading 211-213 F.
Make a glass of ice water and verify it reads 31-33 F.
If either of those are off try another thermometer. Also, if the thermometer is off consistently one way or another, apply that offset. This is a common laboratory procedure. If we had a thermometer reading 213 F and 33 F we knew it was reading 1 F high so if we read 88 F we knew it was really 87 F. The offset was -1 (you record what you should do, i.e. subtract 1).
Also, you didn’t say what thermometer type you had. You should 100% be using an immersion thermometer and not an IR thermometer. The reflectivity on chocolate often does not play well with IR, especially white chocolate.
And after all that the chocolate is still setting up early I 100% sure it is because you and I have not thought of something. I remind you again
In a case like this you start checking EVERYTHING. Is anything else off with your other tempering? Is there something you thought was odd but ok at the time? It was not ok, it was a sign. Did you powder your sugar and not tell me? Powdered sugar can pick up water and hold it even when dried. Are you using an alternative milk powder and not cow milk? Have you tried using my exact ingredients and my recipe? If that works then start changing back to your recipe little by little until it fails and see what changed.
At the end of the day I can’t always help directly.
What I can do it teach you how to troubleshoot your own problems. It is my hope I’ve started you on that path today.
