Week 2: Pastry Cream

Last week, I explored some of the science behind pastry cream. This week, I will look for my reference recipe. I'll start by comparing several recipes to see where the main differences are. I will look at the main ingredients with the salt and vanilla removed since they are mainly contributing to flavor versus the overall chemistry of the pastry cream.

Recipes broken down in percentages from [1], [2], [3], [4], [5], and [6]. Percentages don't include vanilla or salt. Note that these are rounded to the nearest tenth of a percent, so the total values may not add up to a perfect 100% due to rounding error.

Looking at the recipes, they all have a similar dairy (whole milk and heavy cream) content around 58-63%, and the cornstarch content is a few percent. The sugar varies from ~10-22%, which is a pretty wide range, so in the initial tests, it will be good to see when things begin to get too sweet. One general trend that pops out immediately is that the higher the egg content, the lower the butter content. The sum of the egg yolk and butter seems to stay around ~20%, which is likely because they are both thickening. To start exploring this trend a bit more, I will pick a few recipes that span the range of butter versus egg yolk. For Splits A, B, and C, I will use Recipes [1], [2], and [4]. These evenly span the range egg vs. butter content: Split A has no butter and 17.3% egg yolk, Split B has 5.9% butter and 14.2% egg yolk, and Split C has 11.3% butter and 10.7% egg yolk. Recipe [6] is also interesting because it has a similar butter content to Split C at 11.6%, but it ups the egg yolk content to 13.9%, so I will make Recipe [6] Split D. I will add the vanilla and salt content called for in each recipe.

From the top left going counter clockwise: Split A, Split B, Split C, Split D. 

Split A was not very rich and had a thin mouthfeel. It was very sweet and didn't have the distinctive pudding flavor you expect in a pastry cream. This indicates to me that the butter is essential for the rich texture and pudding flavor. Split B had the consistency of mashed potatoes, which I can only assume was due to the very high cornstarch content. It had good flavor, but it was so sweet that I wrote "hurt your mouth sweet" in my tasting notes. Split C had a rich texture and great flavor. It was smooth and more balanced in sweetness. Split D was not very rich and was very bland despite being very similar to Split C, so it seems like the extra egg yolk may have diluted the flavor. Split D was looser than Split C, so maybe you need the thickness for it to feel rich.

I wouldn't go any sweeter than Split C, so this tells me that the right sugar content is ~10-13.3%. Based on these tests, I can also say that to get good flavor, the butter needs to be >~6%, and the egg yolk needs to be <~14%. Split C was the winner this week by far, so it will be my reference going into next week. Next week, I will explore the butter to egg yolk ratio in more detail and in a more controlled way.