Homemade Pudding

Homemade Snack Packs: Chocolate Pudding

A side-by-side comparison of the final product, after 8 hours of cooling in the refrigerator. 

 

The majority of ingredients required to make the pudding. 

The two pans used to cook the pudding, on their respective burners. Red pot contained the pudding with all-purpose flour, and the black pot contained the control pudding with the cornstarch.

The control batch of pudding containing the cornstarch, at the 11:34 minute mark.

The test batch of pudding containing the flour, at the 11:34 minute mark. At this time, the pudding began to release heat in the form of steam, and shortly after began to bubble, allowing for the final ingredients to be incorporated into the mix. 

The final pudding mixture of the control batch, right after it was removed from the stove.

The final pudding mixture of the test batch, right after it was removed from the stove.

For my last experiment, I had absolutely no idea what I was going to make. I spent at least an hour and a half flipping between our book’s table of contents and the various recipes provided within it, and for whatever reason, the recipe I kept going back to was the one for creamy chocolate pudding. So it was at that time, I decided that I would attempt to make creamy chocolate pudding from scratch, a dish that I have never made before.

I began my chocolate pudding endeavor by first acquiring all the ingredients from my local grocery store. The list of ingredients for this recipe included the following:

·         2 teaspoons vanilla extract

·         ½ teaspoon instant expresso

·         ½ cup sugar

·         3 tablespoons Dutch process coca

·         1 teaspoons cornstarch

·         ¼ teaspoon salt

·         3 large egg yolks

·         ½ heavy cream

·         2 ½ cups whole milk

·         4 ounces bitter sweet chocolate

·         5 tablespoons unsalted butter, cut into 8 pieces

According to ingredient list, 1% and 2% milk could be substituted for whole milk, however the pudding would be slightly less rich in flavor if 2% or 1% milk were used. Since the grocery store I bought my supplies from did not have whole milk available, I substituted 2% milk in its place.

Since this recipe came from the section of the book that talked about starch and its ability to prevent eggs from curdling in pastries, soups, and puddings, as well as that the book had stated that in certain cases, flour could be substituted for corn starch, this experiment will focus on the starch added to the recipe. The book also stated that, specifically for the chocolate pudding, flour could be substituted for corn starch in the recipe, however a larger portion of flour would be need, but did not say how much the portion would be increased. Thus, since this was not stated, I substituted the same amount of flour in my test batch of pudding, as the amount of corn starch that was added to my control group of pudding.

My hypothesis for this experiment was that if you use flour instead of corn starch while making pudding, then the pudding made with the flour will be less dense/thick than the pudding make with corn starch, because flour contains less starch than corn starch. Thus, requiring a large amount of flour be added to the recipe.

My null hypothesis was that the type of starch used would not have any effect on the pudding.

My independent variables were the type of starch used—Corn starch vs. all-purpose flour.

My dependent variables were the thickness of the pudding, the amount of time it took to cook the pudding, and the temp. the pudding reached when it was complete.

The standard variables for this experiment were the pots used to cook the pudding (similar pots), the stove used for heating, the heat setting used to cook the pudding (both burners were turned to the middle mark on medium), the stopwatch used to keep track of time (www.online-stopwatch.com), and the thermometer used to take the temperatures of the pudding, the amount of time the puddings were allowed to cool (8 hours) and the rating scale used to rate the thickness of the puddings (1 being of soup consistency, 5 being peanut butter consistency).

After I acquired all the ingredients for this tasty dish, I began my experiment by laying all the ingredients out on my kitchen counter. Once this was complete, I gathered 5 medium sized bowls, a cutting board, a knife, two similar pots, a Wisk, and various measuring cups/spoons. Once I had all my cooking utensils in order I began to assemble the ingredient mixtures.

For this I started by measuring out 2 different batches of 2 teaspoons of vanilla extract and ½ teaspoon of instant espresso, into two separate bowls, one for each batch of pudding, since this ingredient combination would be the last thing added to the pudding. Once this was complete, I measured out ½ cup of sugar, 3 tablespoons of coca powder, 2 teaspoons of cornstarch, and ¼ teaspoon of salt into one of the pots, that I had placed on the stove top, while the stove was still off. This dry mixture was placed in the black pan, and would serve as the dry mix for the control batch of pudding that used the recipe provided from the book. I then measured out a second dry mix batch, consisting of the same quantities of the same ingredients, with the exception of 2 teaspoons cornstarch.  In its place, I substituted 2 teaspoons of all-purpose flour, in order to create the dry mix for my experimental batch of chocolate pudding. This dry mix was placed in the red pot, which I had placed on the stove top, while it was still off.

Once the dry ingredients had been measured out and placed in their respective pots, I than prepared the wet ingredients. These included ½ cup of heavy cream, 2 ½ cups 2% milk, and 3 egg yolks for each batch. Before I added the wet ingredients to the pots, I took the time to prep one other set of ingredients, since they would have to be mixed in as the pudding began to bubble, and time would be important to prevent the pudding from burning.  Thus, I cut up two separate portions of 4 ounces of bitter sweet chocolate, and two separate portions of 5 tablespoons of unsalted butter. A combination of 4 ounces of diced bitter sweet chocolate, and 5 tablespoons of unsalted butter were then place in two separate bowls, for convince, when they would be added at the later stage of cooking.

Once the final ingredients were prepped, I whisked in the premeasured wet ingredients into both of the batches of pudding, and turned the burners on to the middle notch on the medium heat setting. At this time, I also started the stop watch.  The mixtures were continually whisked while being heated, just as instructed. The instructions also stated that the mixture needed to be heated until it bubbled across its entire surface before the chocolate and butter could be added, followed by the final ingredients of vanilla extract and instant espresso. As the mixture started to heat, I noticed a few differences between the two batches, and thus recorded the time at which each batch began to release steam, and the temperature at which both batches where at during this time, in comparison to one another. That is, the pudding containing the all-purpose flour started to release steam after 11:34 minutes of cooking, and had reached a temperature of 177.8 degrees Fahrenheit, while at the same point in time, the batch containing the corn starch did not show any signs of heat release, and had only reached a temp of 137.7 degrees Fahrenheit.   

In addition, the batch containing the all-purpose flour appeared to cook much faster, and thicken up faster than the batch containing the corn starch. This was observed in the total time it took each batch to completely cook, which was completed when all ingredients were fully incorporated into the bubbling batches. The flour pudding took 25 minutes to fully cook, while the batch containing corn starch took 42 minutes to cook. One of the limitations to this finding was that, I had inadvertently place the pans on two different sized burners. The pudding  batch containing the flour was on a slightly larger burner than the pudding containing the cornstarch, and this could have resulted in a faster cooking time, simply out of the fact that the flour batch was in a pan that was in contact with a larger heated surface, were as the cornstarch batch was located in a pot where the heat was more concentrated in the middle of the pan.

As mentioned, the batch containing the flour began to bubble at 11:34 minutes, and at that point, the chocolate and butter ingredients were whisked into the pudding until they were fully incorporated. Once these ingredients were fully incorporated, the final ingredients of vanilla extract and instant espresso were incorporated into the pudding, and the pudding was removed from the heat source, and temp. taken. The final temp of the pudding containing flour was 190.3 degrees Fahrenheit. The same last sequence of steps were followed for the pudding containing cornstarch, when it finally bubbled all, which occurred after roughly 36 minutes of heating. The final temp of the pudding containing corn starch was 180.3 degrees Fahrenheit, with a final cook time of 42 minutes.

Both batches were then removed from the pots, and placed in two separate labeled bowls and place in the refrigerator overnight to cool for 8 hours. After 8 hours of cooling, the puddings were removed from the refrigerator, and tasted and rated on a scale of 1-5 with 1 being of liquid consistency (comparable to soup), and 5 representing fully thick pudding (comparable to peanut butter).

After administering this highly subjective test, I determined that both batches were fully thick, both with consistencies that were comparable to peanut butter. I than had my roommates blindly compare the two batches, and their ratings appeared to support this as, both batches received scores of 5 from both gentlemen. This data is represented in the charts and graphs below, as well as the time and tem data.

Thickness Rating Data	Pudding containing Cornstarch	Pudding containing Flour
Tester #1	5	5
Tester #2	5	5
Tester #3	5	5

Temperature Data-in degrees Fahrenheit	Pudding containing Cornstarch	Pudding containing Flour
After 12 minutes of heating	137.7	177.8
Final temperature	180.3	190.3

Total Cook Time Data—in minutes	Pudding containing Cornstarch	Pudding containing Flour
Time to fully cook	42	25

This graph represents the thickness ratings given to each of the two batches of pudding by three separate individuals. Thickness was rated on a scale of 1-5, with 1 representing a liquid consistency comparable to that of soup, and 5 representing a thick consistency comparable to that of peanut butter. All individuals stated that the consistency of both batches of pudding were identical, and this was observed by there ratings of 5s for both puddings. 

This graph represents the difference in total cook time each batch took to reach the point at which all ingredients were incorporated into the pudding. As can be observed by the graph, the pudding containing flour instead of cornstarch, required almost half as less time to fully cook, than the pudding containing the cornstarch did. While there was a notable difference in the amount of time required, this data may have been dramatically skewed by the fact the each pot was placed on a different size burner, on the same stove. The pudding containing the flour was inadvertently placed on a larger burner than the pot containing the pudding with the cornstarch, which may have caused it to cook faster in general, as compared to the difference in cook time resulting for the difference in ingredients. 

Overall, the pudding turned out very flavorful, and both were very think as already mentioned. While there appeared to be a few differences among the two batches while they were being heated, after cooling both batches appeared to be the same. A few things I would fix if I had to do this experiment again would be to place the pots on the same size burner, in order to get a better gauge as to whether there really is a difference in the amount of time it takes the pudding to cook, for reasons already mentioned. In addition, I would also completely eliminate starch from one batch of pudding, to use as a test group, in order to have a better comparison, to see just how much starch affects a dish like this. In addition, I also would have increased the number of batches made, had more than 4 people test it, and incorporated a less subjective means of testing it's thickness. 

Now that we have discussed the experiment, lets discuss the since behind the importance of starch when it comes to cooking dishes like this.  According to our book, The Science of Good Cooking, eggs appeared to be the delicate ingredient in pastry/soups/custard style dishes that can have a dramatic impact on the texture and consistency of these types of dishes (Editors of Cook's Illustrated & Crosby, 2012). Moreover, it is the way that eggs coagulate, that can either make or break a dish like these, as the rate at which eggs coagulate is directly related to the amount of heat introduced (Editors of Cook's Illustrated & Crosby, 2012). Too much heat and the eggs coagulate into a structure that is so extensive and strong, that the water is actually squeezed out, resulting in the formation of curds (Editors of Cook's Illustrated & Crosby, 2012). While there are various ways to affect the coagulation point of eggs, the chapter focused on the ability of starch to increase the temperature at which eggs coagulate (Editors of Cook's Illustrated & Crosby, 2012).

According to the chapter, primarily cornstarch, and in some dishes flour are needed to increase the coagulation temperature of eggs (Editors of Cook's Illustrated & Crosby, 2012). Cornstarch, in some instances flour, achieve this effect because starch granules release spindly threads of amylose when heated, that interfere with the cross-linking of proteins, and thereby increase the temperature at which eggs coagulate (Editors of Cook's Illustrated & Crosby, 2012). This is very important when it for the stabilization of egg proteins when they are heated, and helps prevent them for clumping and curdling in creamy dishes such as pudding (Editors of Cook's Illustrated & Crosby, 2012). Which is why both puddings were free of clumps and curds. In addition, the increased coagulation temperature allows the puddings to be cooked for much longer and to reach a higher temperature, while remaining clump and curd free, than they would have otherwise had the starch not be added. Which in turn, also makes puddings and custards very thick, which helps explain why my puddings were both very thick (Editors of Cook's Illustrated & Crosby, 2012). Finally, four was a reasonable substitute in this instance, because flour contains 75 % wheat starch, which is similar to cornstarch, simply less concentrated than cornstarch (Editors of Cook's Illustrated & Crosby, 2012). This also helps explain why there was no difference in thickness between the two batches of pudding I made (containing cornstarch vs. flour).

Source Citation:

Editors of Cook. , & Crosby, G. (2012). The science of good cooking. Brookline: Cook's Illustrated