Take a bowl and boil water in it. When it starts boiling then put tomatoes for 5 minutes.
After that remove tomatoes from the boiled water and then put them into cold water.
Now peel tomatoes and cut them into two pieces and remove seeds with the help of a spoon.
Now take pan and put one cup of water then add tomatoes, brown sugar, vinegar and gradually cook them over medium flame for 10 minutes.
After 10 minutes remove the pan from the flame and then add white pepper in it.
Now take a blender and blend tomato mixture in order to make them smooth.
After that take a pan and put all the tomato paste in it and then cook it over a medium flame.
When ketchup gets thick or if the bubbles start bubbling up then remove it from the flame.
When it gets cold you can then store it in a bottle.
You can preserve this tomato ketchup for one week. Please do not add any kind of chemicals in it.