Dahi is the Indian version of yogurt, having similar properties, although their preparation methods differ. The differences are not great, but they do influence the consistency and flavor of the final product. Thus, if yogurt is made with pasteurized milk, dahi is made with fresh milk that has been brought to a boiling point, left to cool at room temperature, and then adding the acidic curd coming from milk left to sit for a day. This will make the milk’s composition to coagulate and form curds as well, the result being a dairy product with a soft and creamy composition, and a slightly sour but also sweet flavor. The same types of bacteria will be present in the making of dahi, which are Lactobacillus delbrueckii and Streptococcus thermophilus, just like in the case of yogurt. Thus, the only significant difference is that dahi is made out of boiled and not pasteurized milk. Concerning the provenience of the milk, any type of milk will do when it comes to making dahi. But, because it is a highly appreciated dairy product in India, where cows are considered sacred animals, cow’s milk is preferred. Dahi can be consumed as it is or it can be added to various authentic Indian recipes.
When making dahi at home, there are some things you need to consider. First of all, it would be ideal to use whole milk if you want to obtain a creamy dahi, as the fat content in whole milk is the best. Use a culture that is not sour nor old, as they will ruin your dahi by making it too sour or, in case of an old culture, watery. Before adding the culture to the milk, like a small quantity of previously prepared dahi, it is recommended to mix it with a few tablespoons of lukewarm milk, turning it into a cream. This will promote a uniform clogging of the milk. Also, you need to bear in mind that temperature is a very important factor when preparing dahi. So, you should bring the milk to a temperature ranging between 80 to 85 degrees Celsius, by using low heat on the stove, so that water gets the chance to evaporate more effectively, resulting in a thicker curd. Then you will have to allow the milk to cool down at room temperature, but don’t allow it to get too cold. The ideal milk is not too hot and not too cold, so checking its temperature by putting a few drops of milk on your wrist is a good way to check its temperature. When the temperature is right, you can add the cultured batch. When dahi is ready, place it in the fridge and, preferably, consume it within two days. Make sure to save a batch for culturing another round of dahi. Again, don’t use batches that are older than two days.