One of the oldest items in my childhood home in Dallas is a yogurt culture. By my father’s estimate, it has been around for 25 years and seven months.

My dad started making yogurt when he and my mother immigrated to America from Delhi, India, in 1980. He has perpetuated the same culture — the bacteria that kick-start the fermentation process — ever since we moved from New Hampshire to Texas in 1992, by saving a bit of the previous batch of yogurt to create the next one.

He grew up eating homemade yogurt, and he makes it at least once a week, with no thermometers or special equipment. He brings a half-gallon of 2 percent milk to a gentle boil, and lets it cool down until it feels about as warm as a Jacuzzi, as he puts it. He vigorously mixes in a spoonful of the culture, then pours everything into a large stainless steel container. The yogurt sits in an unheated oven with the light on for a few hours until it sets, then he puts it in the refrigerator to chill.

I can’t recall a single day, growing up, when the fridge was without yogurt, or as it’s known in Hindi, dahi. We ate it alongside every meal, as a cooling respite to the spices in our dals and sabzis. Yogurt provided body and lift to my mother’s shrikhand, a sweetened cardamom-yogurt dessert, and the animating tang to her kadhi, a spiced soup made from chickpea flour.