Rumford Baking Powder Becomes A Landmark

When I told my colleagues that I was heading to Rhode Island to write a story on baking powder, I was met with raised eyebrows and a few chuckles: "No Pulitzer in your future for this one, Linda," was the not-so-subtle message. But there's more to baking powder than fluffy biscuits, and some simple acid-base chemistry is the key.

Rumford Chemical Works, where baking powder was made, was designated a National Historic Chemical Landmark in a special ceremony on June 12 in East Providence. Ceremonies were attended by Joseph Larisa Jr., the town's mayor. E. Ann Nalley, president of ACS, presented a commemorative bronze plaque to Nancy Moore, president of the East Providence Historical Society and sponsor of the designation ceremony, and Colin Kane of Peregrine, a real estate firm that is restoring the old Rumford Chemical Works complex. The ceremony was also attended by Tom Payne, a representative from Clabber Girl, Terra Haute, Ind., which now owns and manufactures Rumford baking powder.

First, a little bit about baking powder. It is a leavening agent, which produces a similar effect to yeast. It is used to make batter and dough for quick breads rise. In the presence of moisture, baking powder, which contains an alkali (typically sodium bicarbonate) and an acid, react to create carbon dioxide, which accumulates in little bubbles in the baking mixture to make it puff up, giving baked goods a nice texture.

In the 1830s, bakers began adding sodium bicarbonate to sour milk to leaven their dough. The lactic acid in the sour milk reacted with the sodium bicarbonate to produce the carbon dioxide. Sour milk was later replaced with cream of tartar (potassium hydrogen tartrate, a by-product of winemaking), and this combination was the first true baking powder. It offered bakers better control of the leavening process, allowing for more uniform results.

There were a couple of problems with this formulation, however. The components of the baking powder had to be kept separate before use to prevent a premature acid-base reaction. In the U.S., cream of tartar also had to be imported from Europe, and the supply and price fluctuated.

The search was on for a more efficient and economical baking powder, and Eben N. Horsford (1818-93) found it. In a well-received lecture on Horsford given after the plaque was presented, Paul R. Jones, emeritus professor of chemistry at the University of New Hampshire and editor of the Bulletin for the History of Chemistry, told some interesting and quirky stories about Horsford, a civil engineer turned chemist turned baking powder manufacturer extraordinaire.

A German-educated Harvard chemist, Horsford's contribution was to replace cream of tartar in baking powder with calcium acid phosphate. With his business partner George F. Wilson (1818-83), Horsford established the Rumford Chemical Works in East Providence for the manufacture of calcium acid phosphate, which in the early years was made from beef bones treated with sulfuric acid. Horsford took careful precautions to keep the powder dry by adding cornstarch to the mixture. As time went on, mined calcium acid phosphate minimized the need for bones.

Horsford named his baking powder Rumford, after Benjamin Thompson, Count Rumford (1753-1814), a Massachusetts-born British-sympathizer in the American Revolution who, in addition to serving the Elector of Bavaria and marrying Antoine Lavoisier's widow, left Harvard University an annuity of $1,000 to establish a Rumford professorship. Horsford had been the Rumford Professor at Harvard.

In 1856, Horsford and Wilson bought a building in East Providence for packaging and shipping baking powder. In 1858, they built the first factory building, which still stands today. More than 300 acres were bought to develop a working farm to sustain the people who made the baking powder. By 1894, this village of Rumford was called the "kitchen capital of the world."

In 1948, Hayden Chemical Co. of New Jersey bought Rumford Chemical Works. In 1950, Hulman & Co., Terre Haute, Ind., bought the baking powder division and the acid division from Hayden. By 1968 all baking powder manufacture had left East Providence, and the plant closed. But the old chemical works are getting a new life. The Rumford works were bought last year by Peregrine group, which will restore the old buildings and make offices, stores, and apartments.