Fluff master: Swetha Sivakumar on the rise of Eno

Open a Victorian novel and it’s not long before you encounter a doctor prescribing a restorative spell for a sad heroine or beloved dad in a region of hot springs (Bath, in England; Spa, in Belgium).

It has long been known that the minerals in these springs have healing properties. By the 18th century (slightly before the Victorian era, which stretched from 1837 to 1901), doctors in Europe began to decipher why.

Around the mid-19th century, in what is known as the Golden Age of Chemistry, scientists discovered that minerals in spring water that made it so restorative, such as Epsom salt (magnesium sulfate) and Glauber salt (sodium sulfate), could also be manufactured, packaged and sold, eliminating the need for travel.

So it was that in 1852 a British pharmacist named James Crossley Eno created a mix that he named after himself, as other food entrepreneurs of the time did. (Think of the German-Swiss Henri Nestle and his infant formula; the Swiss Julius Maggi and his instant powdered pea soup; the American Milton Hershey and his chocolate-covered caramels).

Eno called his restorative powder a “fruit salt,” not because it was meant to be sprinkled on fruit, or because of its fruity flavors, but because the acids he used in the mix came from citrus fruits. He tested his mix on groups of sailors and found that it aided digestion. Now the restorative material had a new purpose.

In the 1940s, Eno was advertised internationally as a mild remedy for digestive problems. Since its main ingredients are sodium bicarbonate and citric acid, it provides relief during periods of acidity. Drop Eno into the water, and they combine as follows:

3NaHCO3 + C6H8O7 = 3CO2 + 3H2O + Na3C6H5O7. Or,

Sodium Bicarbonate + Citric Acid = Carbon Dioxide + Water + Sodium Citrate

Such solutions produce carbon dioxide gas in the absence of heat (the bubbles you see are actually carbon dioxide escaping into the air).

In the stomach, sodium citrate, the salt formed in this reaction, acts as a buffering agent. Here’s why: An average adult stomach makes about two to three liters of digestive juices per day. An important component of these juices is hydrochloric acid (HCl), which helps break down food during digestion.

The stomach has its own defense against HCl. Essentially, it sheds its lining and generates a new one about every three days.

Now, when a person goes without food for too many hours, eats a lot of spicy or greasy foods, or ingests too much caffeine, the stomach acids are strengthened, bubble up and overflow into the esophagus, causing painful acid reflux. The sodium citrate in Eno acts as a buffer, compensates for the acidity in the stomach and keeps the pH value temporarily stable.

After finding its way from restorative salt to digestive aid, the brand underwent another transformation. In the 1980s it was adopted by busy housewives as a fast-acting leavening agent.

Numerous cookbooks and women’s magazines list Eno as an ingredient in recipes for dishes ranging from bread to jalebis and appams. Many home cooks in India still use it in idlis and dhoklas.

“It was mainly adopted by beginners because it is a much more forgiving ingredient than baking powders,” says Shubhangi Jain, a baking instructor and friend. Because it is milder, measurements do not have to be exact. It has no lingering aftertaste, unlike baking soda, where even a little too much can give a dish a soapy taste.

Eno has significant disadvantages as a leavening agent. While baking soda and baking powder help the batter rise by producing carbon dioxide as the mixture heats, Eno reacts instantly. This means that the batter will not rise much more in the oven than outside. And that’s if the batter is thick enough to absorb the carbon dioxide produced. If the batter isn’t thick enough, the gas will escape before the mixture reaches the oven, and the result will be a deflated or collapsed treat.

Idli and dhokla batters are in the Goldilocks zone in this regard: not too thin, not too fat, but just right. As a result, Eno can help a busy housewife eliminate the long fermentation process altogether or help an under-fermented batter, if the mixture is steamed once it’s made.

I like to think that if James Eno had eaten a dhokla cooked this way, he would have appreciated the inventiveness. I must admit that I prefer traditional fermentation; I think it tastes better. But I’m excited about trying Shubangi’s favorite fruit-salt hack: mixing a bit of the powder into Rooh Afza, for a fizzy, cool drink on a hot day.

(To reach Swetha Sivakumar with questions or feedback, please email [email protected])