Ask the Alchemist #118

This chocolate tempering has me stumped. I’m a pretty experienced candy maker. I make excellent, butter-smooth fondant, plus hard candy, spun sugar, fudge, and taffy, and am reasonably effective at re-tempering melted commercial chocolate. So I understand the crystallization characteristics of sugar, have an excellent “feel” for it. But I have had difficulty getting a feel for tempering the artisan chocolate I make from scratch.

I have been trying to temper my 8th batch, a Nacionale Maranon 75% cacao (65% bean, 10% cocoa butter), to no avail. I thought I had the process finally down. It went pretty smoothly with a Forastero batch tempered two days earlier, and had decent (though not perfect) tempers on an earlier white chocolate, a Criollo and a Trinatario. I was using more of a dark chocolate, wider temperature range on the Nacionale. It was some of my worst-blooming tempering results to date. The second time I heated it to around 129 degrees, to make sure the crystals were melted, and let it very slowly cool in a Corningware bowl, stirring frequently, to 81 degrees, then raised it to 90 degrees, and poured. (I’m just pouring it in a slab and cutting into chunks for now, not adding the complexity of molding while holding the temperature.) Both times, it set very slowly, with layers formed like sandy chocolate shale, dusted with cocoa. Without any reference data to work with, for kicks and grins, next time I will try to re-raise the temp to a lower 87-88 degrees, not 90, and see if that helps.

I have also found that certain chocolate varieties stiffen up (not just thicken) between 82 and 81 degrees, whereas another variety with the same recipe is fine taken to 81-82 degrees, can even drop to high 70s before thickening up. I’m beginning to think there is more than just the recipe, water content, and ambient temperature/seeding at play here. I can understand that the cacao fat percentage can make a difference, but when the fat range is merely 49% to 56%, that doesn’t seem like enough impact. But I suppose it might be a minor factor. And equatorial proximity is a factor.

I am sure that the initial temperature you raise it to matters a great deal. I advanced from making fairly smooth fondant to butter-smooth fondant, by simply ensuring that crystals in the cooking pan were all washed down and dissolved with water and a pastry brush, as cooking begins. This is equivalent to tempering’s initial heating to melt all the crystals, hence why I took the Nacionale up so high.

Is there any data you’ve found (or recorded yourself) correlating effective tempering temperature ranges for the different cacao varieties that you carry?

I wonder if all that complex cacao chemistry impacts the amount of each type of crystal formed, at different temperatures. If that were true, then we should be able to come up with narrower ranges by variety for pure cocoa liquor.

If that is the case, then is it reliable data across crops of the same variety? (I would guess not.) Does roasting temperature matter (once the water has been driven off) – i.e. perhaps the heat-induced chemical changes also affect temperatures at which it tempers? (Perhaps so if the varietal chemistry has an impact on tempering.)

If different brands of cocoa butter were used across batches, that would also make a difference because fat from Equatorial region cacao has a higher melting temp than that of cacaos in slightly more temperate regions. But I’ve been using the same cocoa butter lot, and predominantly cacao from fairly close to the Equator.

By the way, I have found that improperly tempered chocolate goes stale (flat tasting) much faster than properly tempered chocolate, for some peculiar reason. Hence I’m looking forward to getting this Nacionale tempered with a nice clean snap and consistent texture.

Let's see what i can do here to tease out some information. First a few corrections.

Initial temperature of melt as long as it is above about 100 F does not affect tempering at all. A clean slate is a clean slate. Likewise roasting does not affect tempering at all as long as it is a full roast and you are not leaving water in.

Chocolate and fondant are totally different types of chemistry. It's polymers vs polymorphs. The same with the sugar chemistry and polymorphs.

Ok. The rest. In some ways you are trying to see patterns where they don't exist. Or use observations for prediction. Grasping for explanations I know. What I mean is that classifying by Forastero, Trinatario and Criollo from a tempering standpoint is pretty meaningless. Those are just too broad. Frankly, even classifying by region or country does not show that great of correlation. There is some data to suggest that the closer a bean is grown to the equator the higher it's melting point. But that has not really been correlated to how that chocolate tempers. It just helps explain why different chocolates behave differently. Most likely there is a correlation, but I would not be surprised if it came down to combination of factors. Micro climate, latitude, rain fall, cultivar, etc. There is probably a great professional paper in there.

And then you get into the formulations themselves. Sugar percentage, cocoa butter added, total cocoa butter present and other ingredients. Plus a major potential contributor - water. Each of those can raise or lower the tempering ranges needed for a given batch of chocolate. The end result is too many variables and too many unknowns. At the end of the day you have to do just what you are doing. Working out individually what each batch needs and learning the feel for it. I suspect if you were able to plug in all the variables and their weighted effects, what you would end up with is a range of temperatures and a percent probability that a given temperature would work. Maybe you could tease out that this formulation needs to be brought to 80-81 F to seed and 88-89F to temper, and that other one should go lower to 79-80 F and should only be brought to 87-88 F, but at the end, all you end up with is the same pretty standard range is generally accepted.

That all said, I want to offer up some suggestions where I think you might have gone wrong with the Maranon....not because it is Maranon, but just from what you wrote and did. You heated to 129 F. That is total overkill. We are talking a couple degrees here or there in loosing temper. It's why going to 94F for any length of time in your final step destroys your temper. You are getting rid of all the Type IV and V. No matter the formulation, water content or latitude. 100 F is fine. That said, you didn't hurt anything. You just wasted a bit of time heating and cooling more than you needed.

You then brought it down to 81 F. This might or might not be your first issue. The big question is 'Did the chocolate start to thicken?'. All lovely, complicated equations aside, it all comes down to a state change. You cool until it thickens (just barely). The temperature range is only a guide so you know you are getting close and don't end up with a solidified mess. And it is only a 'mess' because it is difficult to work with, not because it does not work. If it did thicken, we can eliminate that as an issue. If it didn't, then it is very possible you didn't for enough Type IV crystals and needed to cool further.

Next you heated it to 90 F and let it cool very slowly. Personally I think this step, regardless of the previous one, probably doomed you. 90 F is high for almost any chocolate. You can go that hot, but you have to cool relatively quickly or be working with a solidly seeded chocolate. And you did just the opposite. The perfect one-two knock out punch. Tempering is a a process ( as you know). It is crystallization. It's almost a living thing. Temper waxes and wanes. It's constantly changing during your tempering batch. And maybe that is a good way to think about it. The Mojave. You could survive at 100 F for a couple days. At 110 F maybe only a day. And should it get to 125 F you only might make it a couple hours. There is an inverse relationship to your survival and how hot it is. But you can also recover. You can go to 125 F for one hour, back into the shade at 110 F for another few hours, and back into the 125 for another hour. And you can keep doing it over and over....until you finally wear out your reserves and perish, maybe only at 100 F because you have so taxed yourself at those higher temperatures. (quick side note clarification - you are only 'killing' your temper, NOT your chocolate). And to link up the analogy, your seed formed at 81 F is your water reserve in the desert. If you didn't make enough, you die sooner. If you made lots (you took it low enough or are using seed) you have more time to work and can survive higher temperatures. So what you did was take it high, and left it high, maybe with enough reserve or maybe not. Probably not since it bloomed.

In regards to trying 87-88 F for 'kicks and grins' the next time, that is exactly what you should do. As I hope you now see. But it should not be 'without any reference or data'. There is LOTS of data and references. 90 F is the upper end. You lost temper. The ONLY direction to take is down. And should you find that does not work, you look at your seeding temperature (making sure it started to thicken). Really, assuming you have low water chocolate with an average composition, there are only two places to troubleshoot a failed temper. Did you form seed (did it thicken) and did you not get too hot (ok, three - did you get hot enough to create form V, but that isn't an issue here) for too long.

So put aside type, origin, latitude and all that and focus on what the chocolate is telling you.

All those things are just there to explain why different chocolates require tempering temperatures, NOT to predict them.

Cool until it thickens, note the temperature, and then bring it up about 7-8 F.

As for the bloomed chocolate tasting flat and going stale, I would counter that is not true. It's temporary. We temper so the chocolate melts in your mouth well. Bloomed chocolate does not melt well in your mouth so the flavor is subdued.