Here in this part, we have two of the most commonly used tomato by-products and that is paste vs puree. Tomato puree is a thick sauce made from cooked and strained tomatoes, whereas tomato paste is concentrated tomatoes that have been cooked, strained, and cooked once more. The primary difference between the two is the consistency of the sauce. Although they are both usable in the kitchen, they cannot be substituted for one another.
- Comparison between Tomato Puree and Paste
A thick puree made from cooked tomatoes, tomato puree is typically considered to be slightly thicker and less liquid than tomato sauce. You can use it in place of tomato sauce, or you can use it as a starting point for making your sauce. If it is to be offered for sale on a commercial scale, the only components that should be included are tomatoes and salt. Tomato paste, pretty simply, is concentrated tomatoes. You can find tomato paste in the form of small cans, jars, or tubes at the shop. These containers are substantially more compact than cans containing tomato sauce or puree. One thing, and only one thing, should be visible on the list of components, and that is tomatoes. If you want to produce your puree, choosing the right kind of tomatoes to work with is quite crucial. 
For example, plum or Roma tomatoes are ideal for making puree since they have relatively low water content and a significant amount of taste. On the other hand, you might use whatever variety of tomato you like most. Tomato paste is commonly created from the aforementioned tomato varietals as well, and it is not difficult to prepare at home. According to the National Center for Food Preservation, tomatoes can be preserved by canning, drying, freezing, or pickling them. Pickling is another method.
- Utilization of Tomato Puree in Cooking
To prepare tomato puree, cut the tomatoes in half lengthwise and scoop out the seeds. (If you want your puree to be free of tomato skins, peel the whole tomatoes before you remove the seeds; otherwise, it is fine to keep the skins on.) Put the tomatoes in a big pot with a heavy bottom, turn the heat up to medium-high, and bring the mixture to a boil. Simmer the tomatoes until they are soft and some of their juices have been released, which should take around ten minutes after the heat has been reduced to medium-low. Carefully purée the tomatoes using either a blender or an immersion blender until they reach a creamy consistency. 
After that, you can preserve your puree by pressure-canning it, as thorough instructions for home canning are provided by the USDA, or you can split it into plastic bags that can be resealed, press out the air, and then store it flat in the freezer. There is no genuine substitute for tomato puree; but, if you are in a need, you can use an unflavored tomato sauce and simmer it down a little bit until it thickens and more nearly resembles a puree. In addition to being used as a foundation or supplement in a variety of soups, substantial stews, sauces, and pizzas, tomato puree can also be found in a variety of pasta dishes, such as lasagna and spaghetti bolognese.
- Tomato Paste in Recipes
You may also prepare homemade tomato paste. Again, the yield, as well as the flavor of the finished tomato puree, will be different depending on the variety of tomato you choose. Tomatoes of the plum or Roma kind are recommended for this dish. To prepare tomato paste, cut your tomatoes into quarters and put them in a large saucepan with a heavy bottom. Add 2 tablespoons of olive oil to the pot as well. Cook the tomatoes on medium-high heat until they become mushy and begin to break down. 
To remove the seeds and skins from the tomatoes, run them through a food mill or a sieve. After that, combine 2 teaspoons of kosher salt with 2 tablespoons of fresh lemon juice in a mixing bowl. After separating the tomato pulp between two big baking sheets with rims, put the sheets into an oven that has been prepared to 350 degrees Fahrenheit. Bake the tomato pulp until it has reduced to a thick paste, which should take around 3 to 4 hours. Check on it every 30 minutes. Put the mixture into jars with a capacity of 4 ounces each, process it in a water bath, and then either freeze it or store it in the refrigerator with a very thin coating of olive spread on top for up to a month. Tomato paste is a versatile ingredient that may be used in a variety of dishes, including meatloaf, chili, pasta, and more. Because it is so concentrated, it is normally only required in a very little amount. If you have any tomato paste left over, you can incorporate a few tablespoons of it into a homemade sauce, spread it over pizza dough before adding toppings, or use it to make a warm dip for garlic bread. All of these options are available if you have leftover tomato paste. 
If you are going to use tomato paste to make pasta sauce, you need brown it a little bit in the pot first before adding water and the other ingredients. This is due to the intense taste that tomato paste possesses.