I saw this term pop up in a quiche recipe concerning the crust - How can you tell if the problem is too little/too much shortening, or too little/too much liquid? If it's out of proportion, can it be "fixed" without creating an inedible cardboard thing?
"Shortness" in dough refers to its tenderness, which is influenced by the amount of fat as well as sugar. If your quiche recipe calls for a short dough, it would be referring to a higher ratio of fat to flour since pastry for quiche typically doesn't include sugar.
Both fat and sugar minimize and break down gluten development which results in "short" protein strands and thus a more tender result. As the fat is rubbed into the flour, glutenin (providing strength) and gliadin (providing elasticity) are coated with the fat which acts as a lubricant to keep the two from being able to link together forming gluten when liquid is added to the mix.
The higher the amount of fat in a dough the more tender it will be. If you want a dough to be flaky then you'd leave the fat in larger particles which will blister to form flakes. If you want a dough that will be moisture resistant to fillings (such as a quiche) then work that fat in finely so that it will be less likely to absorb moisture during and after baking.
Quiche crusts (and crusts for other custard based pies... pumpkin, sweet potato, custard, etc) should first be blind-baked for the crispest crust in the finished result.
As for "fixing" a pastry dough...it's usually easiest and best to simply start over. Water is added a little at a time to avoid adding too much. If too much water is used then more flour needs to be added but with the excessive flour and water then comes additional gluten. If you get a pastry dough too wet, I would be inclined to rub some additional fat into flour and then add that to the first dough rather than just flour alone. Too little shortening will really only be noticed after baking and that's going to be determined through how tough or tender the dough is.
Keep in mind that toughness also depends on the amount you've handled it. Short doughs typically can't be handled too much because the higher amount of fat means that they will warm and get sticky. It is best to refrigerate to firm up the fat rather than add flour as the flour simply dries it out. The tender nature of the dough from sugar means that in some cases they can be impossible to roll out and transfer to a pan. In this case they are usually put into the bottom of the pan and then patted out across the bottom and up the side.
The Oxford English Dictionary has this to say:
IV. Not tenacious in substance, friable, brittle. [Probably connected with branch I through the notion ‘having little length of fibre’: cf. sense A. 3. (= short dung, manure, muck: manure containing short straw and in an advanced state of fermentation.) ]
- Of edible substances: Friable, easily crumbled.
a. of crust, pastry, etc. Cf. short-bread n., short-cake n., short crust n.
c1430 Two Cookery Bks. 52 Þan take warme Berme, & putte al þes to-gederys, & bete hem togederys with þin hond tyl it be schort & þikke y-now. 1594 Good Huswifes Handmaide 17 b To make short paste in Lent. 1700 W. Congreve Way of World iii. i. 46 You may be as short as a Shrewsbury Cake, if you please. 1888 B. Edmondston & J. M. E. Saxby Home of Naturalist 99 A thick cake, which may be made of either flour or oatmeal, and may be rendered ‘short’ by the use of fat.
b. of fruit, meat, etc. to eat short: to break up or crumble in the mouth.
1648 T. Gage Eng.-Amer. 143 This is the Venison of America, whereof I have sometimes eaten, and found it white and short. 1655 T. Moffett & C. Bennet Healths Improvem. xix. 186 Salmons are of a fatty, tender, short, and sweet flesh. 1699 J. Evelyn Acetaria 57 The bigger Roots..should..eat short and quick. 1706 G. London & H. Wise Retir'd Gard'ner I. i. vii. 35 Its Pulp eats short, and its Juice is sugar'd. 1856 Orr's Circle of Sci., Pract. Chem. 337 Vinegar makes the meat short, short meat being easy of digestion.
[Note: friable means "easily crumbled"]
If used in an example for a simple pastry, then i think it would be referred to as flakey and melting in the mouth. Pastry’s should be ‘short’ as they have a crumbly texture, flakes in your mouth, and is very soft. Hope this helps!