Let's pick up where we left off, yeah?
Choose your milk carefully.
Do you need fancy milk to make cheese? No. Do you need raw milk to make cheese? No. (Research your state's or country's stance on raw milk. Where I live it is illegal to sell it.) What are the milk requirements?
Make sure your milk isn't expired. That's a given. Stay away from ultrapasteurized (UP) or ultra-high temperature (UHT) milk. You might not be able to make harder cheeses from ultrapasteurized milk but you can try. Soft cheeses might work. Similarly, try to go with unhomogonized milk or creamline milk if you can find it at a good price. Sometimes I buy fancy milk, but in all honesty, unless I'm really trying to make a super nice cheese, to me, it doesn't matter. That being said, I hear that raw milk cheese is phenomenal. Too bad it's illegal to purchase raw milk where I am.
Bring your milk up to temperature. Your recipe should tell you what temperature you need your milk to be at. Words for the wise: Get a thermometer. Seriously, get one. Also, always use a double boiler. You don't need anything fancy. Just get two pots and stack them. This will give you more control over the temperature of your milk and if it is getting too warm, simply remove the top pot from the double boiler.
You also don't want to scald your milk. At this point it's not too big of a deal (unless you are using raw milk... lucky).
But keep in mind that cheese is a living food. You are going to inoculate it with bacteria, and they can only survive at certain temperatures. In the cheesemaking process, you want to make sure you don't kill off those little guys who are going to make your cheese taste good.
The exact temperature depends on what recipe you are using. But it might be around 80-something degrees Fahrenheit.
The following steps depend on your recipe so from here on out I'm going to simply mention the general steps you will do somewhere in your cheesemaking process.
Add in your Calcium Chloride (CaCl2), annato (if you are using it) and your starter culture (if you are using one). You will want to add Calcium Chloride to your milk if you are not using raw milk. It will help your curd set since homogenization and pasteurization disrupts the calcium content in milk. Adding CaCl2 restores soluble calcium to the milk. Make sure you mix it thoroughly (yet gently) throughout the milk.
Annatto is the colouring that is added to cheese. There is no difference between yellow cheese and white cheese aside from the addition of annatto (Not even in taste, but then again, we eat with our eyes, right?). Annatto will come in a bottle and you will have to dilute it in water. Pour it into your milk and stir. It won't look yellow right away, but your end product will be a yellow cheese. Cheese can turn yellow on its own without annatto but it won't be that neon colour that we Americans are used to. If you use milk from grass-fed cows, your cheese will turn slightly yellow on its own. Grass fed cows will release beta carotene in their milk and it will make the cheese turn yellow. If you suffer from IBD, skip the annatto. Annatto is known to be an irritant for people wIth IBD. (Want a post on this? Let me know)
When you add your starter culture, if it is a dried culture, sprinkle it on top of the milk and let it rehydrate for a minute. Afterward, stir it gently yet thoroughly into the milk. Your recipe might have a ripening time, if it does, cover your milk pot and let it sit for that amount of time. Not all cheeses have a ripening time at this stage. If you don't have one, move on to the next step.
Add the rennet. What is rennet? Rennet is solution of enzymes. What are enzymes? Enzymes are little proteins that make chemical reactions happen faster. Enzymes in rennet make react with the milk to produce curds and whey. Want a post on the science-y details of this? Let me know.
VEGETARIANS BEWARE: Rennet is taken from the stomach lining of animals, so if you want to make vegetarian cheese, use a plant based rennet. How did we (people) ever come up with taking enzymes from the the gut of an animal? Milk used to be carried in sheep stomachs and if it was in there long enough, it would separate into curds and whey. Farmers had to figure out something to do with it instead of throw it away. So now we have cheese.
Back to adding rennet. Your rennet, even the already liquid one should have been diluted in some water, your recipe and your rennet bottle/box will tell you how to do this. Add the diluted rennet into your milk and stir for no longer than one minute. Stir gently but make sure it is well stirred. Put the top back on the pot and allow the curd to set. Your recipe should give you an idea of how long to let it sit.
This is a lot of information, yeah? Let's stop it here and be on the lookout for part three of how to make cheese.