 Curd and cheese are quite different, right? I mean, one is this white, liquidy, jelly-like thing and then there's this much harder, dry block of protein. But the weird thing is, is that both cheese and curd, they're made from milk and they have pretty much the same types of lactic acid bacteria. Then what is it about cheese? What is so special about cheese that it makes it so wildly different from curd? That's what we're gonna find out in this video. Technically, cheese making is an extension of curd making. In order to make cheese, you first have to make curd and then you treat this curd and you finally get your cheese. But how exactly do you treat it? Well, first you remove all the whey from it. Milk has about 80% of casein proteins and the remaining 20% of whey proteins. Now, when you heat the milk, some of these whey proteins, they get denatured but the rest, they remain dissolved in the water. Curd is a combination or a mixture of both the lumpy casein proteins plus the watery whey proteins. Cheese, however, has none of this whey. All of the liquidy stuff is completely drained out through various kinds of methods. The dried cheese is then salted for flavor and then further aged in controlled conditions. Sometimes we also add some extra microorganisms to this cheese in order to get the final texture and the taste that we want in our cheese. So the final product at the end of this cheese making process is either a soft or hard, moisture-less block of protein that has a very specific taste, texture and flavor and a much, much longer shelf life, even sometimes greater than two years as compared to curd and milk. Now, you can see that I've written down the counter characteristics of curd as well compared to the cheese that we have here. So we know that curd or yogurt has this tangy taste to it because of all the lactic acid in it and it does have a long shelf life as compared to milk which maybe stays okay without refrigeration for about two to four days and while yogurt can stay good up to two weeks if it is refrigerated properly, if it is stored properly. Now, let's go back to our cheese. Do you see all of these characteristics? The fact that there's no way in it, that it's moisture-less basically, then it can be soft or hard, the specific taste, texture, flavor, even the shelf life, all of these things, they are affected by a lot of factors in the entire cheese making process. Like the milk source, where is the milk sourced from or the types of lactic acid bacteria that you're using or the way that you're curdling your milk, the rate of acidification or the drying techniques that you're involving in the process or the extra microbes even that you're adding and at what kind of conditions is the cheese being aged at. All of these different things, if you tweak any of these things, the milk source, the bacteria, the extra microbes, anything, even the drying techniques for that matter. If you change any of these things, then you will get a completely different cheese at the end of the process. Let's make some space first before we move on to some of our examples. So I have some space here. Okay, I think this should be good. Now, a really good example is the type of lactic acid bacteria that you're using in your starter culture. So if you use these bacteria, these moderate temperature loving bacteria who operate the best at around 20 to 40 degrees Celsius, they are called the mesophiles. If you use these mesophiles in your starter culture, then you would end up with some amazing cheddar cheese. Meanwhile, if you go ahead and choose the higher temperature loving bacteria or the thermophiles, which operate at around almost up to 120 degrees Celsius, if you use those bacteria as your starter culture, then you would make, you will end up probably making something like Parmesan cheese. Even the way you curdle your milk matters, other than lactic acid, cheese makers also use enzymes to coagulate the milk. The most common enzyme is called chymazine, which is present in this substance called rennet. This enzyme can go ahead and cut or snip off the negative charges of the casein molecules in the milk. Because of that, they end up sticking together and we have milk coagulation. Rennet is perfect for making cheddar, but lactic acid will give you the tastiest block of paneer or cottage cheese. The way you remove the whey also changes with the cheese type. To make cheddar, you have to squeeze and press the moisture out of it in these whey-like structures. On the other hand, to make paneer, all you have to do is drain away the whey with the help of a straining cloth. Now, cheddar and paneer don't need any extra microbes to complete the process, but some cheeses do. They decide the texture and flavor of the final cheese. For example, Swiss cheese, the most characteristic cheese of all time, the cheese with the big holes, the cheese that Jerry is after all the time. Those characteristic holes are the work of a bacteria called propenio bacteria. The name is kind of a tongue twister, but you'll get it. This bacteria breaks down lactose into propionic acid, acetic acid, add carbon dioxide. This carbon dioxide gets trapped in the inside of the cheese and that is why these holes or these eyes are formed. So you see, everything is different for every type of cheese. That's how we have about 1,800 different types of cheese in the world. Now, we can't really say that about curd now, can we?