The Pastry Pirate had a post not too long ago in which she discussed learning why shortening (i.e., the fat you use in baking) is called shortening. (Btw, today is her birthday!) In that post, she wrote:
Do you know why shortening is called shortening?The post suggests that she learned this in her Baking Ingredients and Equipment class. I thought it was really cool, too, as did her commenters. So I mentioned it to Bullock, himself a baker of the serious amateur type and a lover all things technical and historical associated with cooking (or woodworking, for that matter). He was skeptical. As he put it, "Would my 19th century great-grandparents who used 'shortening' have known that's what it did? Did the makers of 'shortbread' name it for its chemical reactions?" That made me wonder, too -- which is older, the science that the Pirate describes above or the words 'shortening' and 'short' in reference to pastry?
It's because shortening, like other fats, is able to shorten the gluten strands that form when water is added to flour and the resulting mixture is agitated (as in kneading or mixing). A shorter, weaker gluten strand and gluten matrix results in more flakiness and tenderness, which is desirable in pie crusts and pastries, for which shortening is most often used.
Here's what the OED shows for the usage history of the word "shortening":
1796 A. SIMMONS Amer. Cookery 34 Loaf Cakes No. 2 Rub 4 pound of sugar, 3 and a half pound of shortning, (half butter and half lard) into 9 pound of flour.Hmm...did the 18th century know about the "gluten matrix"? What's more, look at the 1970 example and its use of "short" as a synonym for tender. That, plus Bullock's mention of "shortbread," made me look up "short," and here's what I found:
1823MOOR Suffolk Words, Shortning, suet or butter, in cake, crust, or bread. 1854SEBA SMITH Way down East 333 We have n't got a bit of shortnin' in the house. 1883Cassell's Fam. Mag. Nov. 758/2 The very reason for boiling the ‘shortening’ with water is that by liquefying the fat a minimum quantity of water can be used. 1970SIMON & HOWE Dict. Gastronomy 347/2 Shortening, a culinary term used more in the United States than in Britain and it applies to fats used in making breads, cakes, pastry etc. All fats, even oils, come under this nomenclature and are used because they make mixtures ‘short’ or tender. 1980Blair & Ketchum's Country Jrnl. Oct. 34/3, 2 tablespoons shortening.
IV. Not tenacious in substance, friable, brittle.Ah-ha, so "short" in reference to pastry means crumbly and has been used at least since the 15th century. (I included def. b. just for interest.) Now I'm pretty positive the 15th century didn't know about the underlying chemistry of gluten, but they did know the effects of the ingredients they used.
[Prob. connected with branch I through the notion ‘having little length of fibre’: cf. sense 3.]
c1430Two Cookery Bks. 52 antake warme Berme, & putte al esto-gederys, & bete hem togederys with inhond tyl it be schort & ikkey-now. 1594Good Huswife's Handmaid 17b, To make short paste in Lent. 1700CONGREVE Way of World III. xv. 46 You may be as short as a Shrewsbury Cake, if you please. 1888EDMONDSTON & SAXBY Home Nat. 99 A thick cake, which may be made of either flour or oatmeal, and may be rendered ‘short’ by the use of fat. 1648GAGE West Ind. 143 This is the Venison of America, whereof I have sometimes eaten, and found it white and short. 1655MOUFET & BENNET Health's Improv. xix. 186 Salmons are of a fatty, tender, short and sweet flesh. 1699EVELYN Acetaria 57 The bigger Roots..should..eat short and quick. 1706LONDON & WISE Retir'd Gard. I. I. vii. 35 Its Pulp eats short, and its Juice is sugar'd. 1856Orr's Circ. Sci., Pract. Chem. 337 Vinegar makes the meat short, short meat being easy of digestion.
So, in short (hahahahaha), it seems that the underlining chemistry of shortening and it nomenclature are simply a happy -- and tasty -- little coincidence. Fascinating.
Oh, and Bullock and his baking grandparents would probably tell you that lard makes the best shortening. Of course, that's not recommended for your vegetarian friends!