Week 3: Basic Shortbread Tart Dough, Pâte Sablée

Last week, I continued my deep dive into Pâte Sablée tart doughs. Two weeks ago, I found that all the recipes I found they generally fell into three categories: (1) high egg content, high sugar, (2) moderate egg content, low sugar, and (3) low/no egg content, moderate sugar. Last week I tried out the the moderate egg content, low sugar recipe group and found an excellent reference recipe (which I called Split D) after a disappointing run the week before with the high egg content, high sugar recipes. This week I will look at the final group: the low/no egg content, moderate sugar recipes. How will they measure up to our current standard?

Table 1: Normalized Recipes [1, 2, 3, 4, 5, 6, 7]. Note that 14 g is ~1 egg yolk.

Week 3: Low/No Egg Content, Moderate Sugar

Recipes 6 and 7 have little or no egg yolk, which allows them to have very low flour content. I'm only going to normalize vanilla and salt in Recipes 6 and 7, and I'll pull my reference from last week for comparison. The splits are thus:

Split H from Recipe 7 is somewhat special compared to the other recipes because it is using three techniques to make the final product more tender. The first is the addition of baking powder, which will create gas as it heats, making a lighter, more tender end product. The second is replacing the powdered sugar with superfine sugar and whipping it with the butter. Whipping butter with granulated sugar creates air pockets in the butter that you wouldn't otherwise get, so in this case, the whipping is an essential part of the recipe, so I am going to deviate from my general procedure for this recipe only. The third is using part cake flour. This is a lot of variables, so it will be hard to tell which of these methods really makes the most difference, but we can do some further tests later to figure this out if this split is successful.

Results

Splits D and H both had good flavor, but Split G had an off flavor. This leads me to conclude that you need at least some egg yolk to contribute to the overall flavor of the tart shell.

Split G was also very tough compared to the reference (Split D). This is likely a combination of the extra sugar making it crispier (and thus tougher) and lacking the additional fat from the egg yolk to shorten the gluten. Split H was incredibly tender and melted in the mouth, but it was so tender that it couldn't be removed from the tart pan without falling apart, causing great heartbreak and anguish. I made another batch of Split H the next day, desperately hoping that it falling apart was a fluke, but I ended up with delicious pieces of my tart shell strewn across the cooling rack again. The tenderness of Split H shows that at least some of the three techniques to add tenderness work.

An unexpected result was that in both Splits G and H, there were issues with the blind baking process. In both cases, when removing the parchment paper from the shell before the second part of the bake, the bottom of the crust stuck to the parchment paper, pulling large layers off of the bottom crust. Sticking at this level is problematic for maintaining the tart shell shape. It is not clear why it happened, but the major commonalities were low flour content and low/no egg yolk content, so these could be possible culprits.

Major sticking to the parchment paper

There are a lot of warnings around only using powdered sugar because any granulated sugar (even superfine) will supposedly leave crunchy bits in the final product. But Split H shows that this is just not true, so we've debunked some lore this week.

Given Split H's fragility, I will take Split D and implement modifications like those used in Split H and our other doughs to try to recover the superior texture while maintaining a more structurally sound shell. And maybe we'll find out more about the shell sticking to the parchment paper along the way too.

If I just wanted to make shortbread cookies, I would go with Split H in a heartbeat. I would be lying if I said I didn't stand over my broken tart and immediately devour the whole thing because it was so delicious and tender. In the coming weeks, I will continue my quest to make Split D tender like Split H while maintaining its structural integrity.