Category Archives: Baking Science

Gelatin ……what is it?

This image comes from a blog called The Daily Postcard.  Check it out!

This image comes from a blog called The Daily Postcard. Check it out!

What is gelatin…..that ubiquitous substance that turns colored water and sugar into JELL-O!?!  Mixed with canned fruit, it serves as a staple on cafeteria buffets.  That may be the vision that most of us have, but unflavored gelatin is also used as a stabilizer in cream-based desserts (like mousse), a thickener in salad dressings and even the structure building agent in marshmallows!  (Look for a marshmallow “how-to” on my Learn page soon.)

So  really, where does gelatin come from?  The Pastry Chef’s Companion  defines gelatin as a substance derived from the bones and connective tissues of animals.  Ewwww! Really?  Yes, but don’t worry.  Gelatin is heated, filtered, purified and sterilized to make it nearly flavorless.

In the bakeshop, we use two different forms of gelatin:  powdered gelatin and sheet gelatin.  With either form, there are two crucial steps to working with gelatin:  bloom and dissolve.  First, gelatin must be bloomed in water to hydrate it.

Here are photos of the first step of working with gelatin powder and gelatin sheets: bloom.

Gelatin powder

Gelatin powder

Bloomed gelatin powder

/ Bloomed gelatin powder

For gelatin powder, add four to five times the amount of cold water to the amount of gelatin.  Let sit for about three minutes until the water is fully absorbed.

Gelatin sheets

Gelatin sheets

Bloomed gelatin sheets

Bloomed gelatin sheets

For gelatin sheets, submerge the sheets in cold water (no need to measure) for about three minutes until the sheets are very pliable.

For both types of gelatin, the next step would be to heat the bloomed gelatin to a working temperature of about 110*F.   Once the gelatin is melted (in the microwave, over a double boiler, or in a warm ingredient of your recipe), then it is ready to incorporate into your recipe.  Once mixed with the other ingredients and cooled, then the gelatin will create its web-like formation that gives the mixture the desired thickness or structure.

Of course, there are plenty more details about gelatin and working with this interesting substance.  Please refer to your recipe for specific instructions.

This reminds me of my childhood.

This reminds me of my childhood.

NOTE:  Jello-O contains color, flavor, sugar (or an artificial sweetener) and instant gelatin, a product that has been processed a bit differently, so it only needs boiling water to dissolve and activate its structure building properties.

For more information on gelatin, check out this site:  http://www.recipes.howstuffworks.com/j-ello.htm

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A good egg!

                                         
What eggs say....by JWU student Rebecca Ramey

What eggs say….by JWU student Rebecca Ramey

For bakers, these are the four major food groups: flour, sugar, fat and eggs.  The  previous baking science blog posts have already given fun facts about flour, sugar and fat, so now it’s time for eggs!

Egg shell color, does it really matter?  Marketing today tells us that brown eggs are healthier than white eggs, and therefore the consumer is charged more.  Is that really necessary?  No.  White or brown, the contents are the same, and the nutrition value is the same.  The color of the shell depends on the breed of the chicken.

Brown eggs vs. white eggs

Brown eggs vs. white eggs

Egg parts:  Shell, membranes, air cell, egg white (albumen), egg yolk, chalazae.

Fun facts:                                                                                                                                          1. The older the egg = the larger the air cell.  When hard-boiling eggs, it is much easier to remove the shell from an older egg than from a very fresh egg.                                                      2.  The less prominent the chalazae (the twisted egg white cord that holds the yolk in place), the older the egg.                                                                                                                             3.  Worldwide, around 1.2 trillion eggs are produced for eating every year. The average person on Earth consumes 173 eggs a year. (www.britisheggweek.co.uk)

Parts of an egg

Egg composition:                                                                                                                            76% water                                                                                                                                     12% protein                                                                                                                                  10% fat                                                                                                                                             2% sugar

Functions of eggs:  structure, aeration, emulsification, flavor, color, nutritional value.                     Structure:  adding more eggs to a product will give it a firmer texture.  Example:  fudge-style brownies have relatively low egg content.  Cake-style brownies have a higher portion of eggs in the recipe.

Aeration:  whipping egg yolks or whites within the MOP of a recipe will incorporate more air into your product.  Some products are leavened solely with the whipping of eggs (example: chiffon cakes).

Emulsification:  the lecithin in egg yolks allows fat molecules and water molecules to combine more readily.

Flavor:  eggs enrich the flavor of products, giving them a more complete flavor profile.

Color:  egg yolks give an eye-appealing rich color to baked goods.  Also, the additional protein in eggs aid in the browning of the crust of breads, rolls or cookies.

Nutritional value:  eggs are jam-packed with protein, minerals and nutrients for their relatively small size.

How do we use eggs?  fried eggs, omelets, quiche, custards, meringues, soufflés, cakes, breads, cookies, muffins…..they are everywhere!

IMG_0773Fried eggs:  note the difference in the size of the yolks.  These were all graded as “large.”

IMG_0597

Over-whipped meringue:  feels like styrofoam.

IMG_0596Perfectly whipped soft-peak meringue.

Meringue topped tartlets

Meringue topped tartlets

Egg custard

Egg custard

Check out these sites:                                                                                                                    The American Egg Board  www.aeb.org                                                                                         The Canadian Egg Council  www.eggs.ca

For a more in-depth look at eggs or just about any ingredient, explore the contents of this great book by Harold McGee.

On Food and Cooking, The Science and Lore of the Kitchen, by Harold McGee

On Food and Cooking, The Science and Lore of the Kitchen, by Harold McGee

“Love and eggs are best when fresh.”  Russian proverb

Does this make me look FAT?

Another baking science lesson…….all fats are not created equal!  In the bakeshop, we use several different types of fat based on the final desired outcome of the product.  In general, we can define a fat as a lipid that is solid at room temperature, whereas an oil is a lipid that is liquid at room temperature.  Certain methods of preparation (MOP’s) require specific types of fat.  Example:  the creaming method for mixing most cookies requires a solid fat like butter (or shortening).  The blending method for making muffins requires an oil.  The rubbing method for making pie crusts needs a solid fat like lard (or butter, shortening or a combination).

Let’s look at the characteristics of a few different types of fats and oils.  Although these photos are showing brand names, I am not endorsing any of these products. Personally, I prefer to use butter in nearly all of my baking recipes, but it is important to know what products are available and the differences between them.

Butter.  There are generally two different types of butter:  sweet cream and cultured.

Unsalted Sweet Cream Butter

Unsalted Sweet Cream Butter

European Style Butter

European Style Butter

Sweet cream butter, a mass-produced butter, is made from cream that has undergone little or no storage which results in a very mild flavor.   It is available in both salted and unsalted varieties.  European style butter is made more slowly with cream that has developed a deeper flavor and often has bacterial cultures added to it to  enhance the flavor. While sweet cream butter has an 80% fat content, European style butter has an 82 – 86% fat content.  The remaining percentages are made up with water, milk solids and minerals.

Margarine

Margarine

Margarine, very similar to butter in fat content, is composed of hydrogenated vegetable oils, flavors,  and colors.  It boasts a lower saturated fat content and less cholesterol, but may also contain trans fats.  If choosing margarine for health reasons, please do your research as there are a variety of brands that are processed differently.

 

 

Butter vs. Margarine, by JWU student Rebecca Ramey

Butter vs. Margarine, by JWU student Rebecca Ramey

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Oil. There are many varieties of oil, including corn oil, canola oil, peanut oil, olive oil, and vegetable oil.  All of these oils are 100% fat and remain liquid at room temperature.  Flavor varies with the type of oil so when choosing a product to use in a baking recipe, I recommend one with a mild flavor.

Unsalted butter

All-purpose shortening

Shortening, a hydrogenated vegetable oil which makes it a solid at room temperature, has very little flavor and a waxy consistency.  All purpose shortening may be used for pie crusts, cookies, biscuits and for frying.  Shortening has an extremely long shelf life and has a higher melting point than butter. (The higher the melting point of the fat, the flakier the product will be.)

Lard, for a REALLY flaky piecrust!

Lard, for a REALLY flaky piecrust!

Lard, rendered and purified pork (usually) fat, has a relatively high melting point that makes it perfect for flaky pastry.  Remember the picture of my blueberry pie from my first post?  That pie crust was made with lard.  Depending on the quality of the lard, some brands may be more suitable for savory dishes as they have a bit of a meaty flavor.  (This particular brand is nearly flavorless.)

Functions of fats:  Fats in recipes provide moistness (muffins), tenderness (cakes), flakiness (croissants), flavor (shortbread cookies) and extend shelf life.  Choose your fat wisely!

The following photos are of some products that rely on fat for their characteristic flavors and textures.

Tender-crisp butter pecan shortbread cookies

Tender-crisp butter pecan shortbread cookies

Palmiers, Tarte Tatin and Bande de Fruit- all use butter puff pastry

Palmiers, Tarte Tatin, Bande de Fruit and Sacristains- all use butter puff pastry

Butter gives them their flaky layers!

Butter gives these croissants their flaky layers and amazing flavor!

What’s your favorite fat for baking?  What makes it your favorite: the flavor, the mouthfeel or how it functions in your product?

.Here’s another of my favorite books!  This edition, set up like a dictionary, gives a brief history, definition or description of everything from basic ingredients to classic recipes.  This book is “must have” for your culinary bookshelf. The Pastry Chef's Companion

 

More baking science…..sugar!

Sugar, sugar….oh, honey, honey…..(anyone else hear the Archie’s song?) Here’s the link to help you get in the mood.  http://youtu.be/h9nE2spOw_o

Another of our How Baking Works lessons focuses on sweeteners, where we examine different classes of sugars: crystalline, syrups and specialty sweeteners.  Crystalline sugars encompass everything from granulated sugar, to brown sugar and powdered sugar, as well as Demerara, Turbinado and Muscavado.  For syrups, we include corn syrup, glucose, molasses, honey and of course (my favorite!) maple syrup.  Specialty sweeteners comprise a variety of products including high intensity sweeteners (such as Splenda and Stevia), dextrose and isomalt .

Tasting demo of different sweeteners.

Tasting demo of different sweeteners.

And yes, we taste them ALL!  You would be surprised at the different flavors that these sweeteners impart.

Pound cake experiment with varying amounts of sugar.  The 100% cake is the correct one.

Pound cake experiment with varying amounts of sugar. The 100% cake is the correct one.

In addition to identification and tasting, we also conduct a few basic experiments.  One experiment explores the functions of sugar by adjusting the amount of this ingredient in a basic pound cake.  We bake a control pound cake using the correct amount of sugar (100%) and then we bake other pound cakes (the variables) using the following percentages of the correct amount:  0%, 25%, 50%, 150% and 200%.  This experiment proves some of the functions of sugar.  In addition to the obvious function of “sweetening,”  granulated sugar also:  provides tenderness, moistness, aids in leavening and provides color (caramelization).  And yes, we tasted all of these too!

Here's a comparison of cakes made just with Splenda or Stevia, and cakes made with a 50/50 blend of sugar and one of these sweeteners.

Here’s a comparison of cakes made just with Splenda or Stevia, and cakes made with a 50/50 blend of sugar and one of these artificial sweeteners.

For this experiment with “high-intensity” sweeteners.  We made the pound cakes with either Splenda or Stevia, and then with a 50/50 blend of Splenda/granulated sugar or Stevia/granulated sugar.  Our findings here proved that high-intensity (or artificial) sweeteners can only provide “sweetness” to a product.  When used as the sole sugar replacement, none of the other functions existed.  Note:  no color, tenderness, moistness or leavening.  Of course, we tasted them and concluded that the blends were much more appetizing.

Cookies made with no sugar, the correct amount of sugar, and double the amount of sugar.

Cookies made with no sugar, the correct amount of sugar, and double the amount of sugar.

Another experiment explored the functions of sugars in relation to the baking of cookies.  For this project, we made cookies with 0% sugar, 100% sugar (the correct one) and 200% sugar.  You can see here how the amount of sugar affects the caramelization, texture and the spread of the cookie.  Taste?  Yes, you guessed it!  Hmm…..by this time, as you can imagine, we are all pretty tired of sweets!  (Education and learning require perseverance!)

So, did you know that sugar has functions other than sweetening?

Baking Science…..how does baking work?

Students in my How Baking Works class, observing a demo.

Students in my How Baking Works class, observing a demo.

So how does baking work? This week we will look at different basic ingredients and how they function within baked products.  For my How Baking Works course, we focus a full day on the particulars of one specific ingredient, conduct experiments and analyze our products.  (Think…..Scientific Method meets The Bakeshop.)

For the first post in this series of baking science, we’ll look at flour and gluten.

Flour: Different types of flours and their protein contents. Why is the protein content of the flour important?  The protein content of each type of flour correlates to the gluten-forming proteins in that flour.  These proteins help give the baked product the desired taste, color, structure and texture necessary for the desired characteristics of that product.  For example, we use cake flour to make cakes light and tender,  and we use bread flour to make breads chewy and satisfying.  In the baking world, we use various flours for different products: cake flour, pastry flour, bread flour, and high gluten flour.

For this experiment we made a basic “lean dough roll,” which consists of flour, salt, yeast, and water.  Our control product (the correct flour for the roll) was the roll made with bread flour.  We also made rolls with cake flour, pastry flour, high gluten flour and a product called Vital Wheat Gluten. This experiment proved the function of flours and the function of protein in flour.

Here are our findings:

  • – the higher the protein content of the flour, the darker the crust of the roll
  • – the higher the protein content of the flour,  the taller the roll will rise
  • – the higher the protein content of the flour, the more open pore structure within the roll (larger air pockets).  More protein means more air (carbon dioxide gas) can be trapped from the yeast fermentation, causing larger air bubbles within the roll.
  • – flour absorbs moisture.  The higher the protein content of the flour, the more liquid it can absorb.
  • -flavor. Flours with a lower protein contain more starch and less flavor.

Lean Dough Rolls

This photo shows our lean dough rolls that were made with the various types of flours, ranging from cake flour (about 6% protein) to vital wheat gluten (about 75% protein). Vital wheat gluten is an additive used to supplement the protein content of products (like whole grain breads) that are made with lower-protein flours such as rye, oat, spelt or buckwheat.

Gluten:  Gluten, a stretchy gummy substance, forms when the gluten-forming proteins in flour (glutenin and gliadin) come in contact with moisture (water) and motion (mixing).  This substance gives our products the stability necessary for proper structure development.  Gluten is a buzz word these days in the world of nutrition.  Gluten-free products are very popular and although a dietary necessity for those who have Celiac disease or a gluten intolerance, they are not healthy for people on unrestricted diets.  Celiac disease is an auto-immune condition where the body (specifically the small intestine) can not properly digest gluten, therefore causing a number of unfortunate side effects.

Check out the National Institute of Health’s website for more information on Celiac disease and gluten sensitivity:  http://www.celiac.nih.gov

Also check out King Arthur Flour’s website for information on flour, recipes, and products:  http://www.kingarthurflour.com

Baking science.  Too much information? Or are you fascinated with this topic?

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My resource for this information, the book How Baking Works, written by food scientist Paula Figoni, serves as the basis of our curriculum for the How Baking Works class, one of the fundamental courses for the IBPI (Baking and Pastry) majors at Johnson & Wales University.