The quality of the ingredients is important, as always, especially the Tomato, But also remember that the longer you simmer the ketchup, the better it will taste.
If you don't want it spicy, you can change the spicy paprika, for a sweet one.
If you don't have Sherry Vinegar, you can use whichever you have on hand.
When you add the Tomato, cook over low heat for at least 1 hour and a half with the lid on, be patient and make sure that it does not stick or burn.
It is essential to put mixture again in the pan to evaporate more liquid as it is necessary to achieve the typical texture of Ketchup, remember that when it cools down it will thicken a little more.
Be careful to never leave the preparation out of the fridge for several hours. Taking good care of the ketchup, it will last at least a month.