Adding baking soda to the milk/sugar mixture may seem like a small detail that you can just ignore, but it will make cooking cajeta a whole lot easier. Boiling milk by itself causes the proteins in it to coagulate, forming lumps. When the milk is more acidic, like goat milk, the lumps get even worse. (This is why most cheese making starts by heating milk and adding an acidic ingredient of some kind). Adding baking soda raises the pH of the milk, which helps the proteins relax and keeps lumping to a minimum.u003cbr/u003eu003cbr/u003eThe other reason to add baking soda is that it will help your recipe develop a strong, sweet flavor. When proteins and sugars cook together for a while, they undergo the Maillard reaction - the same process that makes a seared steak so much tastier than a boiled one. Getting this reaction going in your pot is the key to the most fantastic-tasting cajeta, and it is more likely to happen if you have made your mixture less acidic by adding baking soda.