At the beginning of the most beautiful time of the year, we received a very special order. Santa Claus himself required our support. When he discovered the new varieties of Ritter Sport chocolates, he wanted to take a closer look. They certainly tasted very delicious. However, he couldn’t shake the feeling that the consistencies of the chocolates differed slightly. Santa and his elves pondered, but they couldn’t solve the measuring task. Then he remembered: "During my sleigh rides, I always make a stop at the measurement technology specialist in Sindelfingen. I got it - this is a case for Fischer!"
Needless to say, when Santa calls, we are on the spot! Our experts did not hesitate and put their heads together. The measurement task looked good, but it wasn't very easy! With the right nanoindentation device, it should be possible. Of course, we got the solution: the FISCHERSCOPE HM2000!
The following chocolate varieties were examined to determine whether the cocoa content affects the consistency of the chocolate:
- "Don Schoko 40 %"
- "Die Milde 55 %"
- "Die Feine 61 %"
- "Die Kräftige 74 %"
- "Die Starke 81 %"
The first was the most pleasant and important step: the taste test. If this test is not passed, the consistency won't matter either. Luckily all test items were more than convincing! After the tasting, we established the following hypothesis: The darker, i.e. the higher the cocoa content, the harder the chocolate.
In the second step, the FISCHERSCOPE HM2000 was used. In order to create the same starting conditions, we cooled the different chocolates down to the same temperature. We then directly placed the different chocolate pieces from the refrigerator on the device. After a few test runs, we chose the following test parameters for our measurements:
- Indentor: Vickers
- Maximum test load: 20mN
- Application time: 2 seconds
- Holding time: 5 seconds
- 10 measurements per chocolate
Our experiment procedure was complicated due to the melting properties of the chocolate. In order to keep the temperature steady, we stopped the time we needed to take the chocolate from the refrigerator and place it under the instrument. The time measured served as a reference for all 10 measurements of each chocolate type.
The measurement results indicate: Our hypothesis that the hardness increases with the cocoa percentage was refuted. For a valid interpretation of the results, the ingredients must also be taken into account.
The 40 % and 55 % chocolates contain cocoa mass, sugar, cocoa butter and whole milk powder. The 61 %, 74 % and 81 % varieties are made from cocoa mass, sugar and cocoa butter only. It should also be noted that with a rising cocoa percentage the amount of sugar added to the chocolate decreases and the fat content increases. Thus, the chocolate with 55 % cocoa tends to be softer than the 40 %. For the 61 %, 74 % and 81 %, the hardness also tends to decrease with a rising cocoa percentage. In comparison, however, the whole milk varieties are softer than the chocolates with higher cocoa amount. This can be linked to the addition of whole milk powder. The results therefore lead us to conclude that the consistency of chocolate becomes softer with increasing cocoa content. This can also be explained with the increasing fat content and the decreasing sugar content of the chocolates.
The experiment results using a FISCHERSCOPE HM2000 couldn’t confirm our initial thesis that dark chocolate is the hardest. The ingredients as well as the fat and sugar content are the determining factors for the hardness values of chocolate.
What’s most important: all tested varieties have passed the Fischer quality check with distinction! Let’s hope you were good, so Santa Claus can put your favorite chocolate under the Christmas tree. Our fingers are crossed! The Fischer team wishes you a merry Christmas!