If you wish to increase the shelf life , there is a preservative added to the sauce – sodium benzoate so that its shelf life is more. 
Once you start making sauce at home you will not buy store bought 
Do try and share you comments
INGREDIENTS
- Tomatoes 2 kg ( you will get 1 litre and little more sauce )
 - Garlic 15 to 16 medium garlic cloves
 - Ginger 2 pieces of about 3 inch
 - Dry Red Chilies 3 to 4 deseeded and halved
 - Raisins 1/4 cup
 - Apple Cider Vinegar or White Vinegar 1/2 cup
 - Salt 1 tbsp
 - Brown sugar or Regular 6 to 7 Tbsp
 - Celery little (optional )
 
METHOD:
TO COOK TOMATOES
- Rinse the tomatoes well in water.
 
- Peel and rinse the garlic, ginger and chop them.
 - Halve and deseed the dry red chilies.
 - Rinse the raisins and keep aside.
 - Now in a large casserole or pot or a 4 to 5 litre pressure cooker, add the chopped tomatoes.
 - Add the chopped ginger, garlic, raisins, halved dry red chilies,vinegar, ,celery and sugar
 
- Mix well and keep the pot or cooker on a low to medium flame on the stove top.
 - Keep on stirring at intervals.
 - When the tomatoes soften, switch off the fire. The softening takes about 25 to 27 minutes.
 
- When the mixture is slightly hot or warm, blend the puree with an immersion blender or in a regular blender. If using a regular blender, then don't add too hot of the tomato mixture
 
- Make a smooth puree.
 - With a strainer which is not very fine, strain the puree very well directly into a pot or a large sauce pan.
 - Strain very well.

 
- First rinse the jar. in a large sauce pan heat water till it reaches its boiling point - meaning it has begun to boil.
 
- Immerse the jar and its lid in the hot water. continue to boil the water along with jar for 8 to 10 minutes.
 - Remove the jar with the help of clean tongs and place the jar inverted on a thick towel kept on the kitchen tabletop. let the jar dry naturally.
 
- Keep the pot or pan with the strained tomato pulp on the stove top,
 
- On a low to medium flame, simmer the pulp till it starts thickening and reaches a ketchup like consistency. It Takes about 35 to 40 minutes.
 
 Spread the tomato sauce on a plate. There should be no water droplets from the sides. You can see a slight separation happening. This is alright. But if you want a thick ketchup sauce like the ready made ones, then you have to cook more till the tomato ketchup coats a spoon and remains like that.

- Pour the hot tomato sauce in the sterilized jar. close tightly with the lid.
 - Let the tomato sauce cool and be kept aside for some hours or a day.
 - Then keep it in refrigerator and use after 1 or 2 days.
 
Serve tomato sauce with any snack or appetizer.







