Level: Apprentice
Read Time: 12 minutes
Now I'm studying the book called "INDUSTRIAL CHOCOLATE MANUFACTURE AND USE" 4 th edition by S T BECKETT. and I'm having some doubts in this page which I given below, can you explain what is DHHM and what exactly the figure is saying.
In short that is the abbreviation for a Maillard reaction product that forms upon heating milk chocolate crumb. The figures show how the concentrations change with heat, time and moisture.
More specifically DHHM is dihydro-hydroxymaltol and it is one of the flavor pre-cursors that you get from heating milk proteins in the presence of reducing sugars (like lactose and maltose) which are naturally present in milk powder in the form of lactose.
I’m not going to repeat everything in the chapter. I recommend you go read it here.
I’ve made a Maillard Milk chocolate in the past and wrote a good bit about it.
Somehow I both own Beckett’s book, have read it cover to cover and didn’t bother to look at it when I did my Maillard milk chocolate. With that, upon re-reading it I pulled out way more details than I previously did (I did read it some 15 years ago in my minor defense) and what came to mind was ‘how can we use some of that information to tweak the flavors we want in our milk chocolate?’. The problem though is that 99% of the people reading this are at home, using a Melanger and not a roller mill and that does not accommodate the heating of milk crumb from defatted liquor. We are starting with whole cocoa beans after all. With that in mind I designed a test scheme for evaluating different ways we could benefit from the information in the book while sticking with the basic methods.
From the charts, it was obvious that I needed to pick one temperature scheme, one time and that moisture was an important parameter. But because defatted liquor was used, oil content could also be a factor, but might only be a drop in moisture or an increase in protein and sugar concentration. There was no way to know.
What I ended up with was 8 different milk chocolates to evaluate the effect of heating during different parts of the process as I was not sure at all if heating only the milk would produce different flavors than heating the finished milk chocolate or whether the cocoa solids had an effect. And for that matter, if there was a difference, was one better or worse than another at the same time keeping in mind that crumb is heated in the industry for a reason. Maybe it was just ease of process but maybe it was because it produced a better flavor.
I decided upon 3 hours of heating at 110 C (230 F). Pretty much exactly the data that was presented in the charts but instead of monitoring for moisture, which is not very useful for those of you at home, I varied ingredients (thereby varying moisture) and when I heated the pseudo crumb or chocolate. It is worth noting I officially heated the samples different times as some took longer to get up to 110 C. Once I hit 110 C then I started the 3 hour timers. Finally, in an attempt to reduce user influence and error, I did not stir any of the samples. So I did not get uneven heating I set my oven to only 125 C (~260 F) until the samples were to temperature and then reduced it to 115 C (~240 F) (setting to 110 C had the samples drop to 100-105 C). Over all, most samples were up to temperature in 1 hour and I’m pretty sure you could safely just heat at 130 C for one hour and then reduce to 115 C if you are doing 1 kg of chocolate.
The recipe I used was 25% nibs (same roasted batch), 25% natural cocoa butter, 25% sugar (sucrose) and 25% whole milk powder.
Because I wanted to test and see if oil content had any effect, for half the samples I pressed my nibs to extract the oil and then ground up the resulting ‘powder’ with the milk. So when I refer to powder, I’m referring to the powder I made from the same nibs as the other tests, not commercial cocoa powder. Also for the sake of keeping it easy to read, when I say heated, I mean bringing it up to temperature as I describe above and holding at 110 C for 3 hours.
So here is the scheme I set up
1) Nib Control. Just regular chocolate, not heated.
2) Powder Control. Pressed out the butter, added it back and made regular non-heated chocolate.
3) Nib Control heated. Split sample 1) in half and heated.
4) Powder Control heated. Split sample 2) in half and heated.
5) Nib and milk ground together and heated then made in to chocolate
6) Powder and milk ground together and heated and made into chocolate
7) Milk only heated and made into chocolate with nibs
8) Milk only heated and made into chocolate with powder
In all the cases I used exactly the same amount of Natural cocoa butter and for the powder, added back the butter I had pressed out.
In all cases there was a distinct color change after 3 hours as fully expected although not nearly as much as when I heated at higher temperatures in my previous experiment.
Also, I encountered another issue when post heating the previously made chocolates. They both (sample 3 and 4) got SUPER thick. Just to geek out on you a little, from what I can tell or hypothesize, is that the heat is causing the sulfur in the cysteine amino acids of the milk protein to loosely bond together thereby increasing viscosity. https://pubmed.ncbi.nlm.nih.gov/15675819/ The mechanism is similar as to why when you heat curl hair it retains shape but slowly loosens over time or with more heat. The solution was simply to put the chocolate back in the melanger for about an hour. The sheer broke those loose bonds and viscosity dropped back to where it originally was.
Alright, that is what I did and what I found. In short, none of the chocolates were bad and the heated samples all had significantly more complexity and less perceived sweetness. These are my tasting notes, done blind initially and then not blind so I could compare them against particular samples.
1) Nib Control. Sweet milky aroma. Quite sweet. Mellow. Light in color but without significant complexity.
2) Powder Control. Sweet milky aroma. Sweet. Mellow. Can’t tell it apart from the Nib Control.
3) Nib control heated. Nutty aroma. Less perceived sweetness. There is an overall fuller flavor and more satisfying. Dark in color. This was my 2nd favorite of the test.
4) Powder control heated. Same nutty aroma as the heated nib. Fuller flavor but a little sharper. Touch metallic – This was my least favorite due to an imbalance in the flavor profile. Dark in color.
5) Nib + milk heated – Less nutty than the heated powder/milk. Tastes the same as nib sample where only the milk was heated. Medium color
6) Powder and milk heated. Quite nutty in aroma and flavor. Toffee and caramel flavors. Sweet but not cloying – This was my favorite with a lovely balance and complexity. Medium in color.
7) Nib. Milk only heated – Not too nutty. Tasted basically same as heated nib and milk. Nice but not too complex. Fine. A little milky. Medium color
8) Powder. Milk only heated. Moderate nut. Smooth. Not memorable but not bad. Medium color.
So in this set of testing it was pretty clear to me that there is indeed something to the industrial process of heating the milk/powder crumb that benefits the flavor. Further heating of the cocoa whether as powder or nib with the milk as opposed to milk alone provides more positive flavors. When just heating the milk powder until brown, it didn’t bring out the same flavors as when cocoa solids were added so to my mind clearly there are proteins in the cocoa that are reacting with the milk precursors that don’t happen once the chocolate is fully made. In other words pre-treatment and creation of precursors are important for the most complex flavor profiles but by the fact that 2) was my second favorite does show that some of the complexity can be developed post refining if you are willing to go through a secondary semi-refining step to get the viscosity back into a working range. That all said, and I know it is a bit to digest, I didn’t see any real advantage of heating the nibs and milk together beforehand. My gut feeling is that there was not enough surface area to allow chemical reactions or there was too much moisture. I don’t think it had anything to do with the fat content as the fully fatted post heated control 2 was very good with the main difference being most likely lower moisture and more surface area contact.
To summarize the summary, for the most complexity either make your chocolate and then heat treat it or make powder and heat treat it with milk. All the other options I didn’t find worth the extra work given the modest change in flavor.
Finally, this month’s Kit of the Month will be this 25% of everything milk chocolate made with our new 2020 Wild Harvest Bolivia (not yet available) and I’ll be providing a taste sample of heated and unheated chocolate so you can decide which way you want to make it. If you want to get in on it you have until the end of Friday the 19th to get in on it.