1 gallon whole milk or skim (1 gal. whole milk = about 1 lb cheese)
white vinegar or fresh lemon juice
Put the milk in a large, non-reactive sauce pan and heat slowly to 200 degrees, stirring to prevent it scorching on the bottom. When the milk is hot enough, add about 1/4 cup of vinegar or lemon juice. If the milk is really at 200 degrees, it will instantly curdle, the milk protein and fat separating from the water in smallish white blobs and foam. If this does not happen, keep heating. Use a thermometer, dairy or candy works fine, but some of them are not quite accurate. If you put the vinegar in when the milk is close to the correct temperature, as soon as it reacts, you know it is done. It is not necessary to continue heating once the reaction occurs, however, you will want to let it sit for a few minutes, with an occasional stir.
Place your lined colander in the sink, drain open please, and carefully pour the entire contents (DO NOT skim anything off) of the pot into it. Take your time, and allow the water to drain through the cheesecloth. It will go pretty quickly if you have used butter muslin. If it goes too quickly and nothing is left behind, you will know that your cheesecloth is too coarse and your cheese has gone down the drain! Do not despair, this has happened to many experienced cheese makers, just get finer cheesecloth and try again.
Assuming that all goes well, allow the ricotta to drain and cool until you can handle the cheesecloth comfortably. Gather the ends of the cloth up and tie into a bag which must be suspended over the sink until it stops dripping. You can hang it on the faucet or drape it from a wooden spoon laid across the sink, whatever works. The ricotta will be finished draining in about an hour and be ready to use in any recipe that calls for this type of cheese. You can add a bit of salt if you like. Of, if the cheese is to be used in a desert, add a little cream and mix in well to make a richer product.
If you are not going to use the cheese immediately, pack into a container and either refrigerate or freeze. This cheese freezes well and will always be available that way. It keeps in the fridge a few days.