I’ve been baking the classic back-of-the-yellow-bag Toll House Chocolate Chip Cookie recipe since I was eight years old. It may be the recipe that ultimately led to my baking and pastry degree and decades-long career as a food editor. So imagine my shock when a #Old_Recipes Reddit thread alerted me to the fact that the recipe I’d been baking for years was not in fact the Original Toll House Chocolate Chip Cookie recipe.
According to Redditor aylagirl63, the Toll House Chocolate Cookie recipe of her childhood was different than the one printed on the back of the morsel bags today. The retro recipe produced a thinner, crispier cookie that still had a pleasant chew thanks to one secret ingredient.
Thanks to an eBay listing, the Redditor was able to find a 1970s packaging from Nestle Toll House Morsels. The recipe included the key ingredient she remembered from her childhood: 1/4 teaspoon of water.
While there are a few other differences between the recipes—the retro one calls for half shortening and half butter and uses a higher baking temperature—the ratio of flour to sugar to fat and baking soda was essentially the same with water being the one notable difference.
I baked the two versions side by side.
Fresh out of the oven, the cookies looked similar. However, the retro cookies sank and spread a bit more as they cooled. They also had crispier edges and a chewier center compared to the more modern cookies. Both batches were delicious and equally devoured by my family.
What Water Does in a Cookie Recipe
Adding water to a chocolate chip cookie recipe might sound a bit retro, but many modern recipes also call for it. Sarah Kieffer’s famous Pan Banging Chocolate Chip Cookies—known for their desirable spread and thin crisp edges—call for two tablespoons of water. Ovenly’s popular vegan chocolate chip cookies include water and oil to replace the eggs. There’s even a recipe from Allrecipes that call for two teaspoons of hot water.
Water is already a key ingredient in cookies because eggs and butter both contain it. Adding water to a cookie that uses shortening (or other pure fats) makes sense. Water helps distribute ingredients like baking soda evenly. It hydrates flour (aiding in gluten development) and in the oven, water creates steam that allows the cookies to rise.
Adding additional water can further hydrate the flour and make a cookie chewier. In larger amounts, water in cookie dough can cause a more drastic spread (increasing crispness) and a crinkled texture as the dough rapidly rises and falls in the oven, as seen in the pan banging cookies I mentioned above.
Want to see what water does to your favorite chocolate chip cookie recipe? Start by adding just 1/4 teaspoon of water per cup of flour called for to get a cookie that is a little crispier. Or go all in and add a teaspoon of water per cup of flour for an ultra-thin cookie that will spread into a slender wafer-like texture. It doesn’t take much water to improve your favorite chocolate chip cookie recipe.