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Typical pastry recipes(pate sucre and pate brisee) follow the 2:1 ratio for flour and butter, other recipes (American pie crust, German shortcrust) can have a lower ratio (1.5, 1.29). How does the higher fat content affect the finished product?

user29568
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    Basically, more fat = crumblier, less fat has more structure. – GdD Oct 31 '17 at 09:42
  • @GdD Why didn't you just put that as an answer? That's exactly what I was looking for. – user29568 Oct 31 '17 at 10:08
  • @greedyscholars answer is better because it explains the why, I wouldn't be able to add anything more than that besides that short and pithy summary. – GdD Oct 31 '17 at 10:10
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    @GdD Fair enough haha. If the pastry has more flour, then kneading will become necessary otherwise how is the structure going to form. American pie crust recipes do not have any kneading, yet you get those flaky structures. – user29568 Oct 31 '17 at 10:23
  • @GdD I think the layers of coated fat provide the structure, but preparation wise- the other pastries are very similar especially when done in the food processor, you always start with the same breadcrumbs and then its either enough water or egg to bind. – user29568 Oct 31 '17 at 10:37
  • @GdD, thank you for your summary! Indeed I wrote a lot but did not give a punchline. – greedyscholars Oct 31 '17 at 12:14
  • Go ahead and steal it @greedyscholars, it it works it works. – GdD Oct 31 '17 at 12:16
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    @user29568, I don't know if you have tried but it is possible to make pastries with gluten-free options like rice or buckwheat flour (which are basically pure starch). Even with fat the dough doesn't come together and crumbles completely. For this reason, recipes recommend putting eggs (protein). You still have a hard time opening the pastry without breaking, but after cooking coagulation of the egg helps to hold everything together. The big hero responsible for elasticity is the gluten. – greedyscholars Oct 31 '17 at 12:31

1 Answers1

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Flour (+ water, either directly or from other ingredients such as egg white) gives the pastry structure. As you knead the flour, the gluten network develops and results in elasticity. When cooked, water evaporates from the dough leaving a rigid gluten skeleton.

Fat does not mix with water and thus stay in blobs in between the gluten network. This weakens the gluten structure, making the pastry crumble.

For this reason, you often see in recipes for shortcrust to avoid overmixing the fat. Buttery biscuits such as shortbread crumble more than crackers, which have more water. The same rationale applies to puff pastry. The thin fat layers are impermeable, so water steam gets trapped and exercise pressure upwards, lifting the pastry up.

Quoting @GdD in the comments, the punchline is:

more fat = crumblier, less fat has more structure.

greedyscholars
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    Can you clarify why overmixing the fat is a problem. – mroll Oct 31 '17 at 02:04
  • @mroll, I would not say it is a problem. It all depends on the result you seek. Typically in a shortcrust pastry one is looking to stay on the limit between a pastry that holds itself (structure) and that crumbles under shear. The more you mix the fat, the smaller are going to be the blobs of fat in between the gluten and starch and therefore the less crumbly the pastry is going to be. – greedyscholars Oct 31 '17 at 12:04
  • Thanks for your answer! I was asking it because I was wondering why there are so many recipes out there, with different ratios. I wanted to try my own ratio's. Now, I know a bit more on how to alter the recipe to reach pastry that I like. – user29568 Oct 31 '17 at 23:38