For anyone who has milk that's about to go bad
In a sauce pan, heat milk slowly until it reaches 200ºF. Make sure it doesn't boil.
Once you reach the temp, take off heat. Pour in salt, vinegar, and lemon juice. Stir until combined and let the mixture stand.
The milk should start to curdle at this point. You'll see the curd separate from the whey, a yellowish liquid. Leave it for about 10 minutes.
Scoop out any big curds with a slotted spoon and transfer to a fine-meshed sieve covered with a cheese cloth. Full disclosure: I used a piece of leftover curtain for mine, haha.
Depending on how you want the cheese, drain until your desired consistency. I drained mine for about half an hour and ended up with crumbly cheese similar to feta.
Transfer to a jar. I put some truffle oil in mine and refrigerated overnight. You can probably add herbs here if you want to.
Keep the leftover whey in a bottle and use for future baking.
On my first try, I didn't let it reach 200°F because I was afraid it would burn. So when I put my acid, it didn't curdle. I brought it back to the stove and heated it up to 200°F and added a few more tablespoons of vinegar. It immediately curdled this time around.