There are a few things Indian households would swear by universally, one of which is that homemade curd is better than store-bought yoghurt. The taste of plain white curd is tangier and more prominent, and not drowned out by additional flavourings. In some homes, it's a matter of pride, the treasured starter culture, simply because it has served delicious curd to the family over a long time. And anything that stays a part of our lives for a period of time, starts holding value to us. Homemade curd is such a versatile kitchen ingredient, that it is imperative that we always have some at hand, at all times. It is used to make buttermilk or chaas, raita, lassi, for marinating meats and for thickening curries and much more. It is a great source of protein and fermentation makes it healthy for the gut.
There are certain notes to take into mind while setting curd at home. Even if you don't have a starter culture. There are some techniques and mindful practices to be made into a habit, to ensure a thick set curd at home, every time.
1. Use full fat milk
If you're using toned milk or double-toned milk, then most of the fats in the milk have already been skimmed off. Use full fat or full cream milk to set the curd and in the end, you'll end up with thick, creamy curd.
2. Use earthenware or clay pot
A clay pot has pores that absorb the moisture from the curd. This leads to a thicker and less-watery curd with a dense texture or mouthfeel. You can also use food grade refrigerator-safe glass bowls to set your curd but avoid using metal bowls or containers. The surface of the utensil must not affect the fermentation.
3. Use lukewarm milk when you're adding the starter culture
Normally, full-fat cow milk or buffalo milk is added to a pot and brought up to a boil to pasteurize it. After that's done and the milk needs to cool down and when it is warm or lukewarm to the touch, add the starter. If the milk is too warm, the bacteria in the starter will be destroyed from the high temperature and the curd won't come out as expected. Lukewarm milk has just enough heat to bloom the bacteria in the starter without killing it and creates a warm initial push for the bacteria to grow.
4. Froth the milk and the starter
After the lukewarm milk and the starter has been incorporated, whisk the mixture till small bubbles start to appear. Agitation in the milk and starter mixture allows the lactic acid bacteria to bloom faster and the small bubbles that come up are an indicator of bacterial growth turning the milk sugars into lactic acid and gases.
5. Store the curd mixture someplace warm
The bacteria in the curd mixture are highly active when the temperatures are warm and suitable for its growth. In cold places it is recommended to pour the curd mixture into a casserole and place it on a hot water bath. This is for the bacteria's growth to take place and only when the curd is set after 5-8 hours, only then can we refrigerate it and not before.
6. The pouring process
When the starter is added to the pasteurized milk, in some places people pour the mixture from one bowl to the other. Sometimes they pour it over from up high to create more froth in the milk. This is all in service of the lactic acid bacteria to get incorporated well with the milk and give us the perfect curd, every time.
7. The green chilli process
The bacteria on the surface of the green chillies is beneficial to the process of fermentation of milk. Add a whole green chilly with the stem intact and you'll be treated with a thick-set curd that's ready to be used in a host of applications.
8. If you don't have a starter
Use store-bought unflavoured, unadulterated plain white yoghurt that come in earthen pots and use three to four dallops or spoonfuls of that yoghurt in your lukewarm milk and froth the mixture and set aside to let it ferment. Use the rest to line the walls of the pot or bowl and pour the frothed milk mixture over them and set aside.
9. Don't check on the curd too often
Once the curd mixture is poured into the pot and kept in a warm place, do not agitate the mixture when checking up on it from time to time. The fermentation process is believed to take five to eight hours so, leave it be and check on it only after a duration of time has passed.
10. For cold climates
Under cold weather conditions, it is advised to set the curd inside of a preheated oven. The oven would be turned off, but the residual heat will sustain the growth of the bacteria inside the mixture. If there's no oven in sight, use your trusty sweaters or quilt to coddle the sides of the pot and keep it warm from the cold temperatures outside.