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Getting a rise out of your baking – Leavening in 18th and early-19th century America.


In 21st century America, we eat many types of “bread products”.  There are tortillas, pita bread, naan bread, biscuits, cookies, loaf bread, soda bread, pastries, cakes, and cookies just to name a few.  But how much thought do most of us give to how these are made and why some of them are light and fluffy while others are very flat and tougher?  The difference, of course, is leavening agents – the things that make dough rise and determine just how light and airy the “bread product” will be.  Join us today as we explore the various forms of leavening that were available to bakers in the North American colonies in the 18th and early-19th centuries.


Many scholars believe that the Egyptians were the first to make leavened bread by mixing flour with water, allowing it to ferment, and then baking with fresh dough.  This produced a soft, light bread.  In ancient Israel, women would let some of their dough sit so it could absorb wild yeast spores in the air.  Then, the next time they made bread dough, they would add a small amount of the leavened dough to their new batch.


Types of Leavening


Biological (yeast-based)

Naturally occurring yeast

For a long time, the addition of yeast for leaven was the only way to make the bread rise.  It is exceedingly difficult to date the discovery of yeast leaven, but the first representations of it date from the Ancient Egyptian Empire.  Depending on the version, leavening with naturally occurring yeast was discovered by the Babylonians or by the Hebrews.  The Egyptians and before them the Sumerians mastered the fermentation process: and they made both beer and bread using it. 

Egyptian Wall Painting Showing bread Loaves on the Table
Egyptian Wall Painting Showing bread Loaves on the Table

Today, we use the same sorts of naturally occurring yeasts for making sourdough bread, a bread that gained popularity with home bakers during the recent pandemic.  In the 18th century, the starter that home bakers use for sourdough bread was referred to as “Emptins” which was, according to the Merriam-Webster Dictionary,  a liquid leavening, usually made at home from potatoes or hops and kept from one baking to the next.  In an environment where you baked every day or two, such as what existed in the colonial and early United States, it was important to make sure to make new emptins before all your old was used up.  Especially when living out on the frontier where there was no close neighbor where you could go to “borrow a bit of emptins.”  If not, you would have to wait several days to a couple of weeks to build up a new starter like we do with sourdough today.  What follows is a period recipe for making “emptins” that demonstrates the need for the “starter” emptins if you wanted to bake the next morning.


Take a handful of hops and about three quarts of water, let it boil for about fifteen minutes, then make a thickening as you do for starch, strain the liquor, when cold put a little emptins to work them, they will keep well cork’d in a bottle five or six weeks.

Translated into modern instructions, and a more reasonable quantity of emptins,

¼ ounce of loose-leaf hops

6 cups of water

~3 cups of flour

1Tbs Emptins

Boil the hops in water for 15 minutes.  Strain out the hops and put the liquid in a large bowl.  Whisk in flour until the mixture resembles a sort of slurry, the texture of pancake batter.  When this goop is no longer hot, add the emptins or starter, and allow to sit overnight.  Provided your yeast mixture is warm and happy, it will go crazy in the hoppy-flour mixture and double overnight.  The final mixture will be thick and bubbly. 

Cover the mixture with a loose lid, and place in the fridge, as you would a normal sourdough starter.  (This step was not needed in the past where they baked every day or two.)  Eventually, the whole thing separates into the heavier starter on the bottom, and the hops water on top.  When you want to use the starter, simply stir up the solution, and add a hearty dash of new flour into the mix.  This will feed the starter and help perk it back up.  For best results, feed the starter the day before you wish to use it.  Otherwise, feed your starter a handful of flour every week or so.

Another form of yeast-based leavening used by colonial bakers, especially those who lived near an ale brewery or a tavern that brewed their own ales, is “Barm.”  Barm, also called ale yeast, is the foam or scum formed on the top of a fermenting liquid, such as beer, or wine.  It is a soupy yeast mixture that was used before the invention of compressed yeast to make bread.  Barm became popular in the 15th century when larger brew houses began to form in Europe and was widely used in England for baking and brewing.  Many recipes from the 18th century call for barm.  It is important to note that these were ale yeasts as opposed to those from lagers.  Ale yeast is a “top fermenting” yeast as opposed to lager yeasts that are “bottom fermenting.”  As the names would suggest, the ale yeasts in the fermenters, lived on the top of the fermenting ale mash while the lager yeasts lived on the bottom of the fermenting lager mash.

An Example of Barm
An Example of Barm

In Hannah Glasse’s 1784 cookbook, The Art of Cookery Made Plain and Simple, she offers the following recipe for white bread:

To make White-Bread, after the London Way

TAKE a bushel of the finest flour well dressed, put it in the kneading-trough at one end, take a gallon of water (which we call liquor), and some yeast; stir it into the liquor till it looks of a good brown colour and begins to curdle, strain and mix it with your flour till it is about the thickness of a seedcake; then cover it with the lid of the trough, and let it stand three hours, and as soon As you see it begin to fall, take a gallon more of liquor; weigh three quarters of a pound of salt, and with your hand mix it well with the water: strain it, and with this liquor make your dough of a moderate thickness, fit to make up into loaves; then cover it again with the lid, and let it stand three hours more.  In the mean time, put the wood into the oven and heat it.  It will take two hours heating.  When your sponge has stood its proper time, clear the oven, and begin to make your bread.  Set it in the oven, and close it up, and three hours will bake it.  When once it is in, you must not open the oven till the bread is baked; and observe in summer that your water be milk-warm, and in winter as hot as you can bear your finger in it.

Note, As to the quantity of liquor your dough will take, experience will teach you in two or three times making, for all flour does not want the same quantity of liquor; and if you make any quantity, it will raise up the lid and run over.

The “yeast” she refers to in her recipe is ale yeast or barm. 

Even in the 1830s housewives are still using “barm” in their baking.  Mary Randolph, in her 1836 cookbook, The Virginia Housewife, has a recipe for making what she calls “Patent Yeast” that calls for using liquid yeast as a “starter”.  It also talks about city folks getting their yeast from brewers.


Put half a pound of fresh hops into a gallon of water, and boil it away to two quarts; then strain it, and make it a thin batter with flour; add half a pint of good yeast, and when well fermented, pour it in a bowl, and work in as much corn meal as will make it the consistency of biscuit dough; set it to rise, and when quite light, make it into little cakes, which must be dried in the shade, turning them very frequently; keep them securely from damp and dust.  Persons who live in town, and can procure brewer's yeast, will save trouble by using it: take one quart of it, add a quart of water, and proceed as before directed.



TAKE one or more cakes, according to the flour you are to make; pour on a little warm water; when it is dissolved, stir it well, thicken with a little flour, and set it near the fire, to rise before it is used.  The best thing to keep yeast in, is a small mug or pitcher, with a close stopper, under which must be placed a double fold of linen, to make it still closer.  This is far preferable to a bottle, and more easily cleaned.

Note that these instructions create a dry, portable yeast in the form of little cakes that are dried and can later be rehydrated to activate the yeast in them for use in baking bread later.  This removed the necessity of carrying bottles of liquid yeast with one when traveling or moving out onto the frontier.  I have also seen a similar recipe for making dried yeast cakes using wheat flour rather than cornmeal.


Mechanical Leavening

Mechanical leavening agents are those that require mechanical manipulation to lighten mixtures and add volume: whipping, beating, and/or heating.  Mechanical leavening agents are not ingredients per se; they are the manipulation of ingredients to incorporate air (gas) and/or cause the conversion of moisture to steam.  When ingredients are adequately agitated and then properly incorporated into a batter or dough, they expand (leaven) the product under high heat during baking.  In some literature, steam is a fourth leavening agent category as it is actively at work in all baked goods in combination with air, yeast, and chemical leaveners.


Air leavening is caused by agitating an ingredient to trap air bubbles inside the ingredient, such as whipping egg whites or heavy cream.  The air is lighter than the surrounding batter or dough and it forces the product to rise as it tries to escape.  Most of us have beaten or whipped heavy cream to make whipped cream.  This “whipping” of the cream traps air within the cream’s fat molecules. 

Whipped Egg Whites
Whipped Egg Whites

Similarly, beating or whipping egg whites traps air in the protein molecules of the egg.  Beaten egg whites or heavy cream are folded into batter or dough to leaven and give the baked good an airy texture.  We see this method of leavening a batter in the following recipe for Savoy Biscuits taken from the cookbook titled “The Complete Confectioner or Housekeeper’s Guide written by Hannah Glass and Maria Wilson.

To make Savoy Biscuits.

Take eight eggs, separate the whites from the yolks, and beat the whites till they are very high; then put your yolks in with a pound of sugar, beat this for a quarter of an hour, and when the oven is ready, put in one pound of fine flour, and stir it till it is well mixed; lay the biscuits upon the paper and ice them, only taking care the oven is hot enough to bake them speedily.

Today, Savoy Biscuits are known as Lady Fingers.

Savoy Biscuits
Savoy Biscuits

A modern recipe that makes effective use of this “air leavening” is an Angel Food Cake.  Angel food cake is one-of-a-kind, and no other cake recipe matches its super fluffy, airy texture.  Though it is a type of sponge cake, it differs from other popular recipes because it is traditionally made using no butter or oil in the batter.  Instead, beaten egg whites are the secret to its ultra-light texture.


Steam leavening occurs when water is converted to vapor by heat.  When the moisture in a batter or dough is heated, it converts to steam and evaporates, which forces the batter or dough to expand.  As steam is produced, water (H2O) molecules begin to spread out and take up more space, which forces the batter or dough to expand.  Steam provides “lift” to baked goods as it evaporates.  As the interior of the baked good nears the boiling point, the pressure from the steam produces puffiness.  Then, as the exterior of the baked good becomes firm, it traps the steam.

Boston Brown Bread
Boston Brown Bread

One example of this method of leavening is “steam bread,” one version of which we know of as Boston Brown Bread today.  According to John Mariani’s Dictionary of American Food and Drink, this bread dates to the time of the Puritans.  One theory is that 17th-century settlers steamed bread because few of them had ovens, and it was an easy way to make bread over an open fire.

Wheat flour was often scarce in the American colonies, so “make-do” breads were made from other flours, or a combination of wheat and other flours.  Boston brown bread — called just brown bread in New England — contained rye flour, wheat flour, and cornmeal.  These were mixed with molasses and buttermilk, and the bread was steamed in a kettle over a fire.

A Yorkshire Pudding
A Yorkshire Pudding

Another, more familiar use of steam leavening is the “Yorkshire Pudding.”  With this, the top and bottom set quickly and then the steam from the cooking causes the pudding to rise.  One example recipe of this is from the 1774 edition of “The Art of Cookery Made Plain and Easy” written by Hannah Glasse.

A Yorkshire Pudding

Take a quart of milk, four eggs, and a little salt, make it up into a thick batter with flour, like a pancake batter.  You must have a good piece of meat at the fire, take a stew-pan and put some dripping in, set it on the fire; when it boils, pour in your pudding; let it bake on the fire until you think it is neigh enough, then turn a plate upside down in the dripping pan, that the dripping may not be blackened, set your stew-pan on it under your meat, and let the dripping drop on the pudding, and the heat of the fire come to it, to make it a fine brown.  When your meat is done and sent to table, drain all the fat from your pudding, and set it on the fire again to dry a little; then slide it as dry as you can into a dish, melt some butter, and pour it into a cup, and set it in the middle of the pudding.  It is an excellent good pudding; the gravy of the meat eats well with it.


Chemical Leavening

Chemical leavening agents (e.g., hartshorn, pearl ash, baking soda and baking powder) are compounds that react with other chemicals or reactants to produce expansion of a baked good by releasing carbon dioxide gas.


Hartshorn, also known as baker's ammonia or ammonium carbonate, is a leavening agent used in baking that produces extra-crisp cookies and crackers.  It was made from powdered red deer antlers.  It is a traditional ingredient in German and Scandinavian baking and appears in recipes dating back to the Middle Ages.

You will notice an odor of ammonia while baking, but this will quickly dissipate, and the baked product will not have an odor or taste of ammonia.  Ammonium carbonate turns into three gases when heated: ammonia, carbon dioxide, and water vapor.  No powder residue remains in your baked goods after baking, but not all the gases escape, which means a bit of an ammonia odor can linger for a while.  Once the product cools, the remaining gases will evaporate.  It is not used for cakes or other large items because the ammonia gas cannot evaporate from these.

As this was used primarily for German and Scandinavian baking, in the period that we cover, 18th and early 19th century America, this would be likely to be found only in areas with Germanic (and possibly Dutch) influence such as Pennsylvania and New York.  Also, since the Red Deer was only native to European forests the product would have been quite expensive due to the need to import it from Europe.  While hartshorn can be made from the antlers of mature adult male whitetail deer, the process is time consuming, and I have not found any record of it having been conducted on a large-scale basis here in North America.

Pearl Ash

Pearl ash, also known as pearlash, potassium carbonate, is an alkaline salt that reacts with water or an acid, such as vinegar, lemon juice, buttermilk, etc.) to create carbon dioxide, which then helps baked goods rise.  Pearl ash, made from wood ash, was used as leavening by some Native Americans and, after they taught Europeans how to produce soda ash, they used it to leaven quick breads.

The first step in making pearl ash was to mix water with the ashes of various broadleaf trees to produce potash lye, or potassium hydroxide.  Pearl ash is a purified version of potash.  When combined with an acidic ingredient like buttermilk, sour milk, or molasses, pearl ash produces carbon dioxide bubbles, in a way similar to how yeast does.  Unfortunately, if the amount of Pearl Ash, a strong base, in the recipe is not balanced properly with the acids it can leave a bitter aftertaste in the baked goods.

Pearl Ash appears in Amelia Simmons “American Cookery” published in Hartford CT. in 1796.  The English cookbooks Simmons probably had access to do not mention pearl ash.  Simmons, and other American cooks, therefore, seem to have been well ahead of their time with the four recipes in American Cookery calling for pearl ash.

Gingerbread Made with Pearl Ash
Gingerbread Made with Pearl Ash

As late as the 1820s and 1830s we still find cookbooks calling for the use of Pearl Ash.  This is particularly true of recipes for baked goods that are highly spiced or have good quantities of molasses in them.  We find such a recipe in The Frugal Housewife by Lydia Maria Child first published at Boston in 1829:


A very good way to make molasses gingerbread is to rub four pounds and a half of flour, with half a pound of lard, and half a pound of butter; a pint of molasses, a gill of milk, tea-cup of ginger, a tea-spoonful of dissolved pearlash stirred together.  All mixed, baked in shallow pans for twenty or thirty minutes.

The same cookbook also uses it for dough nuts, pancakes, and short cakes.

Soda (Sodium Bicarbonate)

Baking soda (bicarbonate of soda or sodium bicarbonate) is a chemical leavening agent composed of a natural alkaline powder (a base) that produces carbon dioxide gas when combined with an acid (e.g., sour milk, yogurt, buttermilk, sour cream, or molasses).  The crystalline form is ground to a fine powder for baking.  When baking soda comes in contact with an acid, it creates tiny bubbles of CO2 that push against the batter and cause it to expand.  Baking soda should be kept no longer than one year because it absorbs moisture from the air that weakens its strength.

Baking soda begins to react to acids immediately when they are combined in a moist environment (as for batter and dough).  Heat speeds up the reaction, but the reaction occurs regardless of temperature.  Batter and dough recipes that use baking soda must be baked immediately to avoid the loss of leavening power (gas production).  Preheat the oven and prepare the baking pans prior to combining the ingredients in a soda-leavened batter or dough.

Sodium Bicarbonate was first isolated in the 1790s by Nicolas Leblanc, however, pharmacist Valentin Rose the Younger is credited with the discovery of sodium bicarbonate in 1801 in Berlin.  In 1846, two American bakers, John Dwight and Austin Church, established the first factory in the United States to produce baking soda from sodium carbonate and carbon dioxide.  Initially, they used a Cow Brand trademark on their products.  In 1860 the company adopted the Arm & Hammer logo.

In cooking, baking soda is primarily used in baking as a leavening agent.  When it reacts with acid or is heated, the carbon dioxide is released, which causes expansion of the batter and forms the characteristic texture and grain in cakes, quick breads, soda bread, and other baked and fried foods.  Unfortunately, since the product was not commercially marketed until after 1846, it has little to nothing to do with leavening in the period that this article is examining.

Baking Powder

Like Baking Soda, Baking Powder was a latecomer to the leavening scene.  While the introduction of baking soda made things easier, baking soda still needed to be mixed with an acid.  Since it was cheap and widely available, bakers often used sour milk.  This process was unpredictable, since it was hard to control how acidic the sour milk was, meaning it was difficult to know how much baking soda to use or how long to bake for.  Enter Baking Powder.

English chemist Alfred Bird created the first product resembling baking powder in the late 1840s.  Bird combined cream of tartar (an acidic powder composed of potassium bitartrate) and baking soda, keeping the two apart until they were to be used so they would not react too early.  Unfortunately, cream of tartar was an expensive byproduct of winemaking that had to be imported from Europe, meaning that it was out of reach for many poorer Americans.  In 1856, this need for a viable alternative drove a young chemist Eben Norton Horsford to create and patent the first modern baking powder.  Horsford worked at a time when chemistry was only just beginning and ended up creating the first modern chemistry lab in the United States at Harvard University.  By boiling down animal bones to extract monocalcium phosphate, Horsford developed an acid compound that could react with baking soda to create those desirable CO2 bubbles.

Horsford later had the idea to put the two together in one container.  Water activates them, so he mixed them with cornstarch to soak up any excess moisture and prevent them from reacting prematurely.  Now, instead of purchasing two separate ingredients at the pharmacy (where chemicals were sold at the time), and having to precisely measure out each one, would-be bakers could grab one container off the grocery store shelf and be ready to go.  In 1859 he incorporated Rumford Chemical Works and began producing and shipping baking powder across the United States and around the world.

We hope you enjoyed today's post looking at “How to get a rise out of your baking – Leavening agents in 18th and early-19th century America.”  Please join us again next time when we will look at Common Herbs and Spices Used in the Kitchens of Colonial America and the Early United States.

Until then, while you are here on our website, we would also encourage you to join our blog community (Look for the button in the upper right-hand corner of this post).  This will allow us to inform you when we post new articles.  We also suggest that you return to our blog home page and sample our other articles on a wide variety of late-18th and early-19th century subjects; both military and civilian.

Finally, if you live in Virginia, Maryland, or North Carolina, we invite you to visit The Norfolk Towne Assembly’s home page to learn more about us, what we do, and how you can get involved in our historic dance, public education, and living history efforts.



American Chemical Society.  (n.d.).  Development of Baking Powder.  Retrieved April 1, 2024, from American Chemical Society National Historic Chemical Landmarks:

Child, L. M. (1830).  The Frugal Housewife.  Boston: Carter & Hundee.

Church & Dwight Company.  (1999).  Church & Dwight's Company History.  Retrieved from Church & Dwight Co., Inc.:

Glasse, H. (1774).  The Art of Cookery Made Plain and Simple.  London: W. Strahan.

Glasse, H. (1784).  The Art of Cookery Made Plain and Easy.  London: W. Strahan.

Glasse, H., & Wilson, M. (1800).  The Complete Confectioner or Housekeeper's Guide.  London: J. W. Myers.

Mariani, J. F. (1983).  The Dictionary of American Food and Drink.  New York: Ticknor & Fields.

Mims, B. (2012, December 1).  The original leavener for cookies that you've never heard of.  Retrieved from Los Angeles Times:

Randolph, M. (1836).  The Virginia Housewife.  Baltimore: John Plaskitt.

Simmons, A. (1796).  American Cookery.  Hartford: Simeon Butler.


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