Choose a heavy-bottomed, deep cooking pot. Your regular pasta boiling pot or something similar will work great. Make sure there is enough room for the milk to rise as it comes to a boil.
Pour 1 liter of full-fat milk into the pot. Heat up over low-medium heat while stirring regularly with a rubber or soft spatula to prevent the milk from sticking to the bottom or scorching. Bring the milk to a gentle boil. For 1 liter of milk, this should take about 10–12 minutes.
Switch off the heat and let the milk rest for 1½ -2 minutes. Meanwhile, mix the white vinegar and water in a small bowl or measuring cup. I prefer using a measuring cup with a spout because it makes pouring easier. You can use lemon juice instead of vinegar if you prefer but make sure that no lemon pulp goes in.
Also, place a colander lined with muslin cloth or cheesecloth over a large bowl. Make sure the bottom of the colander does not touch the bottom of the bowl so there is enough room to collect the whey.
Add the vinegar mixture to the hot milk in three additions. After each addition, gently stir the milk to distribute the vinegar. Avoid stirring vigorously, as we want the milk solids to separate without breaking them into very fine particles.
After the third addition, you should see the milk separating into soft white chenna and greenish whey. Once the milk has curdled completely, immediately strain it through the prepared colander. Don't let the chenna sit in the acidic whey for too long, as this can make it sour and affect its texture.
Pour 1 cup cold water over the chenna to rinse away any remaining vinegar. Gather the ends of the cheesecloth to make a pouch and gently press it for 5–8 seconds to squeeze out the excess water.
Place the pouch back in the colander and set a heavy weight over it. I use my heavy mortar for this. Let the chenna drain for no more than 8–10 minutes. We want to remove the excess water without drying it out completely. If you press the chenna for too long, it will lose too much moisture, which makes it dry and difficult to knead into a smooth dough