How does a good meat grinder work?

Before asking what makes a good meat grinder, it seems appropriate to understand what makes good minced meat. That one is simple! Good minced meat is regular (all of the bits are around the same size) and it has preserved its water content. Water: Lean meat is around 75 % water, fat alone can contain up to 30%. When you know that the main difference between a young and an older animal is water content, you can easily understand that everything should be done to preserve it. Old cow burger can be like leather: you don’t have to be a scientist to know that! But why? During cooking, certain proteins such as collagen dissolve in the water of their cells. The flavours migrate and link up. You need this water in your mouth to know what you are eating and if, absurdly, you were to succeed in removing all the water from a pâté, you would have a completely inedible lump of grease and fat. Grind yes – press no! You will have noticed that when you cook young meat, veal for example, it gives off a lot of water. Especially if the veal was not raised in natural conditions. You will also have noticed that when you freeze merguez sausages, they give off more water than when you cook them fresh. This is down to the cell walls. For the veal, the meat is not “finished” and the cells are fragile