So, here it is... 15 pages on fat and pie crust. Hope you like it!
THE EFFECT OF TYPE OF FAT IN PIE CRUST
Amy Tobey
FCSC 212: Foods II
April 9, 2012
The old saying goes, “There’s nothing more American than apple pie.” Being an American girl, I have to say pie is one of my favorite baked foods of all time. The part I like most, however, is the crust. Therein lies my dilemma. I have been experimenting with different ways to make pie crust for about a year now, and up until the time of this experiment, I had not come up with an acceptable crust.
This experiment, then, has been in the works since this summer when I asked my boss how to make a pie crust and used olive oil instead of shortening. The next time I made the crust, I used butter. The results were entirely different. The main points of this experiment for me personally are 1) to demonstrate that there is a difference between fat used in a recipe of pie crust and the outcome of said crust, 2) to find out why this difference exists, 3) to finally produce an acceptable pie crust and 4) to find the superior fat to use when preparing the crust of a pie. Having gone through with the experiment, I feel confident that I have my answers to these questions.
Pie crust, or pastry, has certain standards that are to be observed to obtain the best possible quality. According to Betty Crocker’s New Cookbook, “Perfect pastry is golden brown and blistered on top, [has a] crisp brown undercrust, tender [meaning it] cuts easily and holds its shape when served, [and is] flaky and crispy.” By changing the fat of the pastry, I altered the flakiness, the tenderness, taste, and color of the pastry. Color and taste are depended on the type of fat because each fat has its own flavor and color naturally. Color can also be added to the pie crust before baking by brushing it with milk, moistening it with water and sprinkling it with sugar, or by mixing an egg wash and brushing the crust with it. To prevent excessive browning, pies can covered with aluminum foil which is removed 15 minutes before the end of the bake time. How the type of fat determines flakiness and tenderness will now be discussed in further detail. “The proportion of fat is probably the most important determinant of quality in pastry especially in creating flakiness. Large amounts of fat are required to produce a flaky crust.” Flakiness is determined by the size, firmness and ease of spread of fat particles. “When fat is cut in small, cold pieces that are incorporated into the dough without being creamed or absorbed by the flour, the fat will then melt during baking, and leave empty spaces where steam may collect to leaven and lift the layers of the dough.” The air pockets left make the pastry flaky with more air pockets (or blisters) giving flakier texture. The type of fat used will determine the flakiness of the crust as well. “Firmer, plastic, 100% fats such as hydrogenated shortenings and lard produce the flakiest pastries… Shortening is softer and more pliable than cold butter, so it coats the flour more easily and can be rolled out even when refrigerated.” The water content of butter can cause more gluten formation when it is used in pastry, but high-quality butters have less water content, making them most desirable for use in pastry. Butter’s flavor lends itself to pastry making, yet it tends to harden when refrigerated requiring more effort to roll out the dough. “Oil is the least desirable fat for making flaky pastry because it coats each flour particle, resulting in an extremely tender but mealy (grainy) texture.” Tenderness is another very important quality in pastry. “Tender products are easily crushed or chewed; they are soft and fragile.” The same factors that affect flakiness of a crust contribute to tenderness, namely the type of fat chosen, how much of it is used, how much the dough is handled, and the temperature of the dough and fat. “Increasing the water in a given recipe decreases the tenderness of pastry.” This is significant when thinking about the water content of butter. One could conclude from this statement and what has been said above about butter that a pastry made with butter will be less tender than one made with pure fat. If the fat is increased a more tender pastry results. “Matthews and Dawson (1963) found a significant correlation between flakiness and tenderness in pastry. Pastries that scored high in flakiness also scored high in tenderness.” Using oil or melted fat is expected to increase the tenderness of a pastry while decreasing the flakiness because the fat is completely dispersed throughout the dough, leaving no room for blister formation. Finally, “folding and rerolling pastry increases flakiness, although it decreases tenderness and may cause the flakes of dough to be closer together or more compact.” This is due to the fact that the more one handles pie dough, the more the dough will hydrate and the more gluten will form. I used four different kinds of fat in this experiment. Each has its own unique qualities that contributed to the outcome of the pie crust it was used in to produce. For my experiment, I used Crisco, olive oil, butter, and coconut oil. Oil is a liquid at room temperature, while butter and Crisco are said to be plastic fats. Plastic fats contain both liquid oil and solid triglyceride crystals with the consistency depending on how many solids to liquids the fat contains: more liquids result in a softer fat, and more solids make the fat harder. “The liquid phase acts as a lubricant, enabling the solid crystals to slide past one another, and thus conferring moldability on the fat.” Palm oil has a very strange way of acting, being solid when cold and liquid at room temperature. Crisco contains soybean oil, fully hydrogenated palm oil, partially hydrogenated palm and soybean oils, mono and diglycerides, TBHQ and citric acid (antioxidants). Because it contains hydrogenated ingredients, a discussion of the hydrogenation process is in order. “Hydrogenation is the process of adding hydrogen to unsaturated fatty acids to reduce the number of double bonds. The purpose of hydrogenation is twofold: to convert liquid oils to semisolid or plastic fasts, to increase the thermal oxidative stability of fat, thus shelf life.” Being easily workable, they are manufactured to be flavorless, have a high range of plasticity, contain 100% fat, and have the greatest shortening power of all fats. Because Crisco is the standard in baked goods, I decided to use this as my control group for my experiment. I expected to get a very flaky crust with good color, bland taste, and adequate tenderness. The olive oil I used in the experiment was virgin olive oils from Italy, Spain, Greece, and Tunisia. “Olive oil is 75% monounsaturated.” “Monounsaturated [fat] is liquid at room temperature and is found chiefly in plants.” They have a health advantage because they reduce serum cholesterol and the appearance of coronary heart disease. Based on the previously mentioned research, I would expect this fat to produce the most tender pie crust with a mealy texture and be the least flaky of all due to the oil molecules coating all of the flour particles in the pie crust. My third variable of fat was coconut oil. The particular type of coconut oil I used was described as 100% mechanically (expeller) pressed naturally refined organic coconut oil by its label. “Fats and oils derived from plants grown in tropical areas of the world are referred to as tropical fat or oil. They are typically high in saturated fat content and contain an appreciable amount of short-chain fatty acids.” Coconut oil has the highest amount of saturated fat, weighing in at 90%, making it stable against oxidation and hydrolysis. Honestly, I did not know what to expect with this particular fat. Because it is solid when cold and oil at room temperature, I knew that if the dough got warm at all, I would be looking at a very tender, mealy pastry. However, if I kept it cold throughout the process, I might end up with a stellar pie crust. This was my wild card of the experiment. Finally, I used salted butter with ingredients of cream (milk), and salt. “Butter… contain[s] water and milk (20%) in addition to a variety of fat or oils (80%). Therefore, butter… [has] less shortening potential than lard, hydrogenated shortening, or oil.” Butter will hydrate the starch found in flour, causing it to swell and toughen the dough. Because of this factor, I expected the pie crust made from butter to be less flakey, a little tenderer, and more flavorful than the pie crust made from Crisco. I was curious to see in the taste test if the flavor of the butter would cover over the diminished flakiness of the pastry. Experiment: Pie Crust
In order to see if the type of fat contributes significantly to the overall texture, taste, and mouth feel of pie crust, I am going to change the type of fat used in a recipe of pie crust. My control group will be using shortening, and I will experiment by using butter, coconut oil, and olive oil. I am choosing butter because I use it a lot in my own cooking instead of shortening, coconut oil because it is a peculiar beast and I’d like to see how it will perform, and olive oil because the text book made such a big deal about how you get a totally different result with oil than solid fat in pastry.
Recipe Used in Experiment
¾ cup flour
1/8 teaspoon salt
1/3 cup of shortening, butter, coconut oil, or olive oil (depending on group)
1 tablespoon beaten egg
1 tablespoon and ¾ teaspoon ice water
¾ teaspoon vinegar
Combine first three ingredients until shortening is the size of peas. Blend last three ingredients and add to dry. Roll into a ball, refrigerate for at least 1 hour. Roll out dough between two sheets of waxed paper. Transfer to baking sheet lined with parchment paper. Dock dough. Bake 10 minutes in 475 degree oven.
I took notes on how the recipe came together for each variant of fat used. While I used the same recipe for each kind of fat, altering only the type of fat used, I found that the process, along with the results, were as different as the fats used to make them.
Pie Crust A was made with Crisco. When I cut the Crisco into the flour mixture, I got pea sized particles. When I added the wet ingredients to the fat mixture, silky soft dough formed that had lots of volume. After refrigerating for an hour, Pie Crust A rolled out beautifully, evenly, and flake formation was observed even at this stage in the process. A small amount of the dough stuck to the waxed paper. After baking, I had a beautiful, flaky crust with bland flavor and lightly browned edges.
For Pie Crust B, I used olive oil. The cutting in process produced a green, pasty liquid in the bowl. The product turned from paste into dough when I added the liquid mixture to it, but the dough was very soft and dense. After refrigeration, the oil oozed out of the plastic wrap. This made for easy rolling out because none of the dough stuck to the waxed paper. Before I put it in the oven, it had a green tint to it, was oily, and there were no flakes visible. After baking, the crust was very oily still; the oil bubbled out of the dough and coated the top of the crust. A light golden brown color was achieved, as was a shine from so much oil. This pie crust also crumbled when I tried to cut it.
Challenges were presented by Pie Crust C in which I used coconut oil in the preparation process. Things went relatively smoothly with the cutting in process as pea sized particles formed. The adding of liquid formed silky soft dough that was only slightly denser than Pie Crust A. But when I took it out of the refrigerator after an hour to roll it out, Pie Crust C was hard as a rock. It broke in half. I had to leave it out for a few minutes to soften because it crumbled when I tried to roll it out straight from the fridge. After this fiasco, it stuck a little to the waxed paper when I rolled it out, but I also observed flake formation already. When Pie Crust C final emerged from the oven, it was the lightest color of all the pastries for the day, and had a soft white tint to it. Also, it was fluffier than the rest of the pastries, and held together well.
The final variation I used for fat was butter which I incorporated in Pie Crust D. When I cut the fat into the flour, a creamy paste resulted. Adding the liquid to the fat mixture gave me dough that resembled cookie dough. The dough was very soft but dense. The olive oil dough was the only dough denser than this one. After an hour of refrigeration, the dough was difficult to roll out between the two sheets of waxed paper; however it had a smooth texture when I had finished this process. Instead of seeing a lot of flakes like I would expect from pastry dough, I felt I had rolled sugar cookie dough on my hands. After baking, the pastry came out golden brown, slightly less flaky and tenderer than Pie Crust A and C, and held its form nicely.
For the tasting section, I had several surveys my classmates filled out for me. I also had my land lady, Dee, and three chefs from Bon Appétit try my pie crusts. Dee liked the olive oil pastry best and did not like the coconut pastry at all. The chefs unanimously voted for the butter pastry as the best.
A copy of the survey used will follow the chart demonstrating the taste test results. Each category of external texture, internal texture, flavor, and color was ranked from 1 to 5 by participants, 1 being I hate it and 5 being I’m not sharing. This was a blind tasting because I wanted to get genuine responses based on how participants perceived the finished product and not the ingredient that went into its formation. (DEAREST BLOG READERS, I COULDN'T FIGURE OUT HOW TO GET THE CHART IN HERE. SORRY!)
Pie Crust Assessment
External Texture is Flaky: Nice layers developed throughout and crisp
Internal Texture is Tender and Blistered: Gives way easily to the tooth and nice air pockets throughout
Flavor is even: not overpowered by fat by complements filling
Color is nice Golden Brown: not burned
Please check most appropriate box based on standards above:
Pie A | I hate it 1 | Take or leave it 2 | I like it 3 | I want more 4 | I’m not sharing 5 |
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Pie B | I hate it 1 | Take or leave it 2 | I like it 3 | I want more 4 | I’m not sharing 5 |
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Pie C | I hate it 1 | Take or leave it 2 | I like it 3 | I want more 4 | I’m not sharing 5 |
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Pie D | I hate it 1 | Take or leave it 2 | I like it 3 | I want more 4 | I’m not sharing 5 |
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Additional Comments:
According to the survey results, Crisco did the best as far as external texture goes. This was followed closely by butter, then coconut oil, and lastly olive oil. For internal texture, Crisco was again the crowd favorite followed by butter, coconut oil, and olive oil. In the flavor category, one participant could not detect flavor among any of the pastry variations and simply wrote, N/A. I substituted this with a score of 1 across the board. Butter was the leader in flavor, followed by coconut oil, then Crisco, and finally, olive oil. In the color category, one participant noted the yellowish color of the olive oil pastry. Butter won in this category followed by Crisco, coconut oil, and olive oil. Butter was in the top two performers in all categories, Crisco was in the top two in three out of four categories, and coconut oil was in the top two in one category. Olive oil was the bottom performer in all categories.
Percentage wise, out of 45 possible points, butter received 64% in external texture, 66% in internal texture, 68% in color and 77% in flavor. Use butter if you want a flavorful and beautiful looking crust. Crisco received 73% in external texture, 71% for internal texture, 53% for taste and 75% for color. Crisco is the standard for pie crust because of how well it performs with the texture elements associated with high quality pastry. Coconut oil performed with a 62% in external texture, 62% in internal texture, 60% for flavor, and 68% for color. If all you are concerned about is taste in your pie crust, coconut oil is second only to butter in this category. Finally, olive oil received a 51% in external texture, 55% for internal texture, 40% for flavor, and 48% for color. While oil crusts can be used in savory pie dishes, in this particular experiment olive oil proved to be an epic fail. Any option would be better than using olive oil for crust making.
The results of the experiment agreed unanimously with the expected results from the science data. Crisco is the standard for pie crust because it is 100% fat and that creates the layering effect so necessary to the blistering and tenderness of pastry. Butter’s taste and ability to brown make it an acceptable substitute in pastry crust making, however it cannot compete with Crisco’s textural development in the pastry because of the water molecules it possesses. While coconut oil has a taste all its own and created a fluffier pastry, many participants did not like its textures and color as much as Crisco or butter. Finally, the olive oil pastry performed poorly, as expected. Not only did it create a mealy texture like the texts said it would because of the coating of the flour molecules, it had a strange color throughout the process and a heavy taste because of the type of oil used.
This experiment has taught me that not all fats are created equal. Each has its own part to play in baking, and each one will change the outcome of the final product dramatically. My personal favorite was coconut oil in pastry, but I also realize that different people have different preferences when it comes to baking. If the standard is to be upheld, then Crisco is the way to go. I also learned that butter covers over a multitude of sins simply because it tastes so delicious. However, there is a reason why most pie crust recipes are written with shortening as the main fat. Nothing competes with 100% plastic fat when it comes to giving pie crust its famous textures.
BIBLIOGRAPHY
Brown, Amy. Understanding Food: Princles and Preparation, Fourth Edition. Belmont, CA: Wadsworth, Cengage Learning, 2011.
General Mills, Inc., Minneapolis, Minnesota. Betty Crocker's New Cookbook. New York: Macmillan, 1996.
Pauline C. Paul and Helen H. Palmer, Eds. Food Theory and Applications. New York: John Wiley & Sons, 1972.
Vaclavik, Vickie A. Essentials of Food Science. Gaithersburg, MA: Aspen Publishers, Inc., 1999.
APPENDIX: Experiment Pictures
The top picture shows the pastry dough’s texture before being refrigerated. The middle picture portrays the density of the various dough. They have not been moved from their position in the top photo. Finally, the picture on the bottom shows the pastry just prior to the taste test and sampling done in class.
