Cookbook:Leavening Agent
| Leavening Agent | |
|---|---|
| Category | Basic foodstuffs |
Cookbook | Recipes | Ingredients | Equipment | Techniques | Cookbook Disambiguation Pages | Ingredients | Basic foodstuffs
Leavening agents are those components that fill doughs and batters with pockets of gas.[1][2][3][4][5]
Characteristics
[edit | edit source]Basic principles
[edit | edit source]The basic principle of leavening is the incorporation, generation, and/or expansion of gas in(to) a mixture. This leavening is then made permanent by the setting of these gas cells into a more solid structure. Though the exact mechanism of action varies slightly depending on the type of leavening used, the same general process proceeds for all types. First, seed pockets of air are incorporated into a raw dough or batter.[6][7] If not sufficiently aerated, these pockets must then increase in size through the generation and/or expansion of gas,[3][8] which can occur through heat and other processes, depending.[6] For example, water expands and turns to steam when heated.[6] The expanded pockets must then set into a sturdy structure before they rupture and gas ultimately escapes from the mixture.[3][6][7] If the structure does not set, it will deflate when the gas escapes or shrinks back down.[6]
Note that the incorporation of seed air cells in the raw product is critical to texture in baking, since these cells will expand but not develop de novo during baking—too few or too many air cells can impact the crumb and texture of the final baked product.[6] Since the expanding gases tend to move into existing air cells,[3][5] a small number of cells will create an irregular and coarse structure of pockets.[6]
The gases that most commonly play a role during the leavening process are atmospheric air, carbon dioxide gas, and steam,[3][6][7] though others can also play a role. Atmospheric air leavens when it's incorporated into a mixture, steam develops when moisture in the mixture is heated, and carbon dioxide can evolve through a few different mechanisms. Individual leavening agents are typically categorized into three main groups—physical/mechanical, biological, and chemical—based on the way the gas pockets develop.[2][5][6][9]
Physical leavening
[edit | edit source]The principal and simplest physical leavening agent is room air,[6][7] which is incorporated into the mixture by mechanical agitation.[7][9] Sifting, beating, creaming, and whipping/foaming are all ways of incorporating air pockets into a mixture,[3][5][7][9] though the amount of air varies by technique and ingredients.
The second common physical leavener is steam.[6] As water in the mixture heats up, it turns to steam and expands by over 1000 times,[3][6] expanding the air cells in the process. Any water-containing ingredient (e.g. eggs, milk, etc) will contribute to the steam.[6][7] Note that the oven must be properly hot for maximal evaporation and steam leavening,[3][6] and preparations leavened mainly by steam usually need to be cooked in a fairly hot oven.[6][9] Choux pastry and puff pastry are examples of products leavened almost entirely by steam.[3][5][6]
Biological leavening
[edit | edit source]This type of leavening is done primarily by yeast,[3] which ferment sugars and produce carbon dioxide gas as a byproduct.[3][6][9] This carbon dioxide expands the air pockets and leavens the mixture.[3] Among the leaveners, biological leavening is somewhat slow, requiring long rest periods to allow the fermentation to take place.[9]
Chemical leavening
[edit | edit source]Chemical leavening involves a relatively straightforward chemical reaction that produces gas as a byproduct.[3][8] Baking powder and soda accomplish this by combining certain acidic and an alkaline products in an aqueous mixture, which react to generate carbon dioxide gas.[7][8][10] Ammonium carbonate doesn't require an acid component, instead decomposing into gas when heated.[7] Chemical leaveners are generally fairly fast-acting,[7] making them suitable for mixtures that cannot hold onto air for an extended period of time.[1][11] Because they sometimes leave an aftertaste,[9] however, they must be used judiciously.
Selection and storage
[edit | edit source]It's important to select the correct leavener for the dish you're making,[4][7] since it will significantly affect the end result.[12] Generally, dry goods-style leaveners like chemical leaveners and some yeasts should be stored at cool room temperature in airtight containers.[3][6][8] Keep them away from moisture,[13] which they will absorb.[3][8]
Use
[edit | edit source]Leavening agents play a couple roles in baked goods. Obviously they leaven the final product, increasing the volume and decreasing the density.[5][7][9][14] However, they also contribute to other characteristics like the grain and crumb structures,[7] and using a leavener that affects the pH will also often affect color.[7] They also tenderize the final product by thinning out the cell walls,[6] and they can affect the spread of free-form products.[7]
Techniques
[edit | edit source]Altitude
[edit | edit source]Leavenings in a recipe may need to be adjusted at higher altitudes. This is because the lower atmospheric pressure causes gases to expand more; as a result, a low-altitude recipe may need to have the leavening decreased to prevent structural issues like collapse.[3]
Sifting
[edit | edit source]Some powder leaveners can clump, which prevents their even distribution and often causes pockets of unpleasant flavor. To prevent this, sift them before incorporation.[6]
Bench tolerance
[edit | edit source]The term "bench tolerance" refers to how well a dough or batter can tolerate being left to rest before baking and setting.[6] If the leavening is fast-acting at room temperature but the mixture cannot hold onto the gas, it will lose the leavening power before it makes it into the oven and has its structure set.[6] Baking soda has relatively low bench tolerance, for example, while ammonium carbonate has greater bench tolerance.
Mixing
[edit | edit source]Mixing is often critical to the successful outcome of leavening. Undermixed mixtures will have too few air cells and therefore an uneven and coarse texture when these expand.[6] With overmixing, on the other hand, there will be too many air cells, and the cell walls will be overstretched and weak.[6] These will collapse and contribute to poor volume and texture.[6]
Substitution
[edit | edit source]Different leaveners are generally not interchangeable with each other; to do so, you would have to make some pretty significant changes to the recipe.
Index
[edit | edit source]Recipes
[edit | edit source]References
[edit | edit source]- ↑ a b McGee, Harold (2007-03-20). On Food and Cooking: The Science and Lore of the Kitchen. Simon and Schuster. ISBN 978-1-4165-5637-4.
- ↑ a b Rinsky, Glenn; Rinsky, Laura Halpin (2008-02-28). The Pastry Chef's Companion: A Comprehensive Resource Guide for the Baking and Pastry Professional. John Wiley & Sons. ISBN 978-0-470-00955-0.
- ↑ a b c d e f g h i j k l m n o p Gisslen, Wayne (2016-09-21). Professional Baking. John Wiley & Sons. ISBN 978-1-119-14844-9.
- ↑ a b "5.1: Introduction to Leavening Agents". Chemistry LibreTexts. 2017-10-25. Retrieved 2025-01-09.
- ↑ a b c d e f Stamm, Mitch (2011-07-01). The Pastry Chef's Apprentice: An Insider's Guide to Creating and Baking Sweet Confections and Pastries, Taught by the Masters. Quarry Books. ISBN 978-1-61058-027-4.
- ↑ a b c d e f g h i j k l m n o p q r s t u v w x y Figoni, Paula (2010-11-09). How Baking Works: Exploring the Fundamentals of Baking Science. John Wiley & Sons. ISBN 978-0-470-39267-6.
- ↑ a b c d e f g h i j k l m n o Zhou, Weibiao; Hui, Y. H. (2014-08-11). Bakery Products Science and Technology. John Wiley & Sons. ISBN 978-1-119-96715-6.
- ↑ a b c d e Labensky, Sarah; Martel, Priscilla; Damme, Eddy Van (2015-01-06). On Baking: A Textbook of Baking and Pastry Fundamentals, Updated Edition. Pearson Education. ISBN 978-0-13-388675-7.
- ↑ a b c d e f g h Gibson, Mark (2018-01-04). Food Science and the Culinary Arts. Academic Press. ISBN 978-0-12-811817-7.
- ↑ Goldstein, Darra (2015-01-01). The Oxford Companion to Sugar and Sweets. Oxford University Press. doi:10.1093/acref/9780199313396.001.0001. ISBN 978-0-19-931339-6.
- ↑ The Chefs of Le Cordon Bleu (2011-12-02). Le Cordon Bleu Patisserie and Baking Foundations. Cengage Learning. ISBN 978-1-4390-5713-1.
- ↑ Ruhlman, Michael (2008). The Elements of Cooking: Translating the Chef's Craft for Every Kitchen. Black Incorporated. ISBN 978-1-86395-143-2.
- ↑ The Culinary Institute of America (CIA) (2011-09-13). The Professional Chef. John Wiley & Sons. ISBN 978-0-470-42135-2.
- ↑ Friberg, Bo (2016-09-13). The Professional Pastry Chef: Fundamentals of Baking and Pastry. Wiley. ISBN 978-0-470-46629-2.