Liberal Arts Blog — The Mysteries of Yeast (3000 BC), Baking Soda (1846), and Baking Powder (1856)

John Muresianu
3 min readOct 14, 2020


Liberal Arts Blog — Wednesday is the Joy of Science, Engineering, and Technology Day

Today’s Topic — The Mysteries of Yeast (3000 BC), Baking Soda (1846), and Baking Powder (1856)

What’s the difference between yeast, baking powder, and baking soda? All are leavening agents. One is biological (yeast) and the other two are chemical — one just a salt (baking soda), the other a combination of salt and an acid (baking powder), making it a “complete” leavening agent. Today a few notes on each. Experts — please chime in. Correct, elaborate, elucidate.

BAKING POWDER: A Harvard Chemist and the Revolution of 1856

1. Cake as we know it today was the child of a Harvard chemist named Eben Norton Horsford (1818–1893). Before Horsford baking was a grueling, unpredictable process.

2. Horsford was the Rumsford Professor of Physics at Harvard and it is from this title that the commercial product (above) gets its name.

3. How bad was it before Horsford? “You’re talking upwards of 12 hours of rising, usually more like 24 hours, Basically, forget about the joy of waking up and deciding to make pancakes.” (Jessica Carbone, National Museum of American History)

YEAST: finicky, unpredictable unicellular organisms used without being understood for 5000 years

1.“Researchers speculate that a mixture of flour meal and water was left longer than usual on a warm day and the yeasts that occur in natural contaminants of the flour caused it to ferment before baking.”

2.“The resulting bread would have been lighter and tastier than the previous hard flatbreads.”

3. “It is generally assumed that the earliest forms of leavening were likely very similar to modern sourdough; the leavening action of yeast would have been discovered from its action on flatbread doughs and would have been either cultivated separately or transferred from batch to batch by means of previously mixed (“old”) dough.”

NB: above, a block of compressed fresh yeast.

BAKING SODA — a salt (sodium bicarbonate) that needs an acidic catalyst (eg. yogurt or buttermilk)

1.“Baking soda is often used to leaven quick-bake items such as pancakes, muffins, scones, cakes, and even some fried foods.”

2. Has many other uses than baking: as a deodorant, pesticide, cleanser.

3. First isolated by French chemist Nicolas LeBlanc in the 1790s, sodium bicarbonate was first marketed as baking soda by the Church and Dwight company in 1846. under the Arm and Hammer brand which still sells like hot cakes.

The Great Uprising: How a Powder Revolutionized Baking

Baking powder

Eben Norton Horsford

Science of Yeast — The Story of Yeast | Red Star Yeast

Baking Soda: Exploring the Science of Baking Soda

A link to the last three years of posts organized by theme:

PDF with headlines — Google Drive


Please share the coolest thing you learned this week related to science, engineering, or technology. Or, even better, the coolest or most important thing you learned in your life related to science and engineering.

This is your chance to make someone else’s day. Or to cement in your mind something that you might otherwise forget. Or to think more deeply about something dear to your heart. Continuity is key to depth of thought.



John Muresianu

Passionate about education, thinking citizenship, art, and passing bits on of wisdom of a long lifetime.