“These are heavenly and should be called ‘Oh-no-I-shouldn’t’ cookies. They’re terribly rich, but terribly good, particularly when served with coffee as a dessert.”

Grace Barr, Orlando Evening Star Food Editor, 1968

The Back Story of Sweetened Condensed Milk

In New York, during the early to mid-1800s , the most dangerous food a child might consume was fluid cow’s milk. With germ theory yet unknown, contaminated milk was a leading cause of child mortality.

The Voyage

Gail Borden, a self-taught food scientist, attended The World’s Fair in London in 1851, where he received awards for his invention of a shelf-stable meat-biscuit (think protein bar). Though revolutionary, the dehydrated meat didn’t sell well because of its unpleasant taste. While on his return voyage to New York, Mr. Borden witnessed first-hand the horrors that raw milk could hold. Two dairy cows were brought on board the ship to provide milk for immigrant babies whose families had booked passage to America. During the journey, the cattle became sick with an infectious disease and died. In turn, the children fell ill and lay dying in their mother’s arms. Mr. Borden was moved with compassion.

The Quest

Upon his return, Borden immersed himself in the development of a sanitary shelf-stable baby formula. With no knowledge of germs or bacteria, Borden knew something needed to be done to stop the “incipient decomposition of milk.” First, he boiled cow’s milk in a pot to reduce the amount of liquid to make it more transportable. Then he added sugar. Unfortunately, the result of boiling milk in an open vessel was a burned, bad-tasting mass. Having learned the hard way with his meat-biscuit, Bordon knew that taste and appearance would be key to the success of his product. He went back to the drawing board.

The Science

Hearing about a curious way that Shaker’s processed medicinal herbs by boiling them in an enclosed vacuum pan, Mr. Borden arranged to spend some time with them to learn about the process. He tried the vacuum method with milk, which resulted in a pleasant tasting product with a creamy milk-like appearance. By boiling the milk in an enclosed vacuum pan, it killed any bacteria that was present and prevented any other bacterial exposure during the cooking process. Bordon also discovered that by adding a substantial amount of sugar,  the shelf-life of the milk was greatly extended since bacteria cannot grow in such a sugary mixture.

Cook’s Science 2016 from the editors of America’s Test Kitchen explains that sweetened condensed milk has 60% of the water removed and has 40% to 45% added sugar. The editors note that an open can of sweetened condensed milk can be left at room temperature for several weeks without spoiling.

The Patent

Borden did not understand the science behind the process he had developed. He just knew that it stopped the decomposition of milk, it tasted good and kept for a long time. His application for a patent on the vacuum boiling process was denied for several years due to the lack of scientific knowledge to understand what he had actually done. In time, science caught up, and in 1856, Borden was awarded the patent he sought. Little by little, the new baby formula began to catch on and is credited with saving the lives of thousands of children. Sweetened condensed milk was to be Gail Borden’s greatest accomplishment.

The Fortune

Always a man of hard work and humble means, Borden’s fortune was finally made in 1861, when the U.S. Government ordered sweetened condensed milk as part of the rations for the Union army during the Civil War. Canned, compact, and calorie-dense, the rich fluid served the soldiers well, not only through the Civil war but also during WWI. Sweetened condensed milk was later included in the foodstuffs dropped into besieged West Germany during the Berlin Airlift of the late 1940s. Returning soldiers shared their enthusiasm for the product, and “Borden’s Milk” was on its way to becoming a pantry staple.

The Legacy

Advertising was important to the Borden company from the beginning. First, for baby formula, then as soldiers and their families began enjoying sweetened condensed milk in their coffee and tea, the company’s advertising pivoted from filling a nutritional need to becoming the quintessential ingredient in making desserts from ice cream to fruitcake. The printed advertisements exploded from black and white scientific-style ads in newspapers to full-page colored ads in magazines. During the mid-1960s, a recipe for Borden’s Magic Cookie Bars, with sweetened condensed milk as the “magic” ingredient, burst onto the baking scene, and desserts have never been the same.

The Recipe — 1970s

While researching this article, I was interested to learn how the recipe for Magic Cookie Bars has changed over the years. In a magazine ad from the 1970s (below), the recipe calls for one cup (6 oz) semi-sweet chocolate or butterscotch morsels, a 3 oz can or 1-1/3 cup flaked coconut, and a 15 oz can Eagle Brand sweetened condensed milk. The directions say to melt the butter or margarine in a saucepan before pouring it into the baking dish to be mixed with the graham cracker crumbs. The order given for layering the remaining ingredients is illustrated in the ad with sweetened condensed milk poured over the top.

The Recipe — 1999

In a magazine ad from 1999 (below), the recipe for Magic Cookie Bars instructs the baker to preheat the oven to 325* if using a glass pan. The butter or margarine is to be melted in the baking pan in the oven, then combined with the graham cracker crumbs or chocolate cookie crumbs. The sweetened condensed milk is then poured over the crumb crust with the other ingredients layered on top. The can size of sweetened condensed milk was reduced to 14 ounces, and the recipe doubled the amount of chocolate chips to twelve ounces. Yum! Once layered, the home cook is instructed to “press down firmly with a fork” to bind the ingredients together. Some substitutions are suggested at the bottom of the recipe — mini M&Ms, dried cranberries, raisins, mini marshmallows or butterscotch chips. Its evident that part of the “magic” in Magic Cookie Bars is the variety of ways the recipe can be personalized. Several Christmas’s ago, a coworker substituted white chocolate chips and Craisins for the usual semi-sweet chocolate chips. They were amazing! It seems that Magic Cookie Bars are limited only by one’s imagination.

A Final Note: Not everyone calls these bars Magic Cookie Bars. Sometimes they are called Seven Layer Bars, Hello Dollies, Coconut Dream Bars or Screaming Eagles. I call them delicious!