In most scenarios, you can use marinara sauce and ketchup interchangeably. However, the ketchup will be slightly lighter and thinner than the thicker and more complex marinated sauce. Tomato sauce may be too thick for a pizza, while marinara may be too thin for dishes such as eggplant, Parmesan and chicken parmesan. Since both sauces are made with tomatoes as a base, it is possible to replace the marinara with tomato sauce.
Using marinara instead of ketchup can make a recipe vegetarian friendly and is a great way to save time when preparing weekday dinners. That said, marinara isn't as heavy or flavorful as ketchup, so the flavor and texture of the finished dish will be very different. Because the two sauces look similar (and can sometimes even taste similar), we often use the names marinara and tomato interchangeably. However, the two sauces are not the same.
According to Taste of Home, marinara sauce cooks much faster than tomato sauce (often less than an hour) and has a less complex flavor profile that usually consists simply of tomatoes, garlic and oregano. Tomato sauce, on the other hand, requires hours of slow cooking and is made with more abundant ingredients, often including a creamy base of roux, meat, and other vegetables and various herbs. As a result, ketchup tends to be much thicker and more robust than its marinated counterpart. So when it comes down to that, how are the two really different? In short, ketchup has much more depth and complexity than marinara sauce, plus a longer list of ingredients.
It's best to think of marinara sauce as a basic form of tomato sauce, especially since its flavor notes, cooking time and ingredient list are short and sweet, according to Paesana. The marinara sauce is also quite fine compared to the thick texture of ketchup. I've even seen a celebrity chef I worked with use ketchup and red pepper as a substitute for ketchup when he had no other options. If you want to add condiments, you should check that the canned tomatoes you are using are not already seasoned.
Nowadays, you can find ketchup in all kinds of flavors, and that makes it easy to add flavor quickly to recipes. If you have any form of tomato paste hidden in a closet, then you can create your own tomato sauce substitute. Although this method is less commonly used, you can use some tomato soup that you have in your pantry to create the perfect tomato sauce. Marinara sauce and ketchup are often used interchangeably and for clear reasons; the two look and taste quite similar to each other.
But before delving into their differences, let's talk about what ketchup and marinara sauce actually are. Some of these types of products are pre-seasoned, but others are not, so it's worth checking before seasoning the sauce too much. If you don't have ketchup on hand, but the dish you want to prepare requires it, it can be helpful to have a backup plan. After letting it cook, the finished sauce will have an almost candied and thick consistency, and will taste sweet, rich and caramelized.
The rich flavor and thick texture of ketchup make it more suitable for smothering foods such as a sauce. Pizza is a great example of this, as marinara sauce is often used to keep ingredients in place while giving a light tomato flavor. Of course, ketchup is wonderful in Italian pasta dishes such as spaghetti and lasagna, but it is also used to prepare dishes such as shakshouka. You can add a variety of different herbs and spices, depending on your personal preferences, and at the end of the process, you'll have the perfect tomato sauce to add to your dish.