What causes a tomato sauce to have a bitterness and getting rid of it?

Question

My tomato sauce is coming out great, lots of flavor, especially after I was able to reduce it following the tips here

However, it is still slightly bitter. What causes a tomato sauce to have a (in my case, slight) bitterness and how do you get rid of it?

Is there an anti-bitter technique that is commonly used.

Answer

A few things can cause tomato sauces to become bitter:

• Overcooked spices. Both basil and oregano can become bitter with long simmers. Add them near the end of the process.
• Under-ripe tomatos. Store bought tomatoes are often picked green and ripened in the store. These tomatoes make less sweet sauces (which may be contributing).
• Cooking in an aluminium pan. Aluminium reacts with the acid in the tomatoes and adds an off-putting flavour.
• Seeds/skin in the sauce. Both seeds and skins can be bitter.

You can improve a bitter sauce by adding a small amount of baking soda (or salt), and something sweet (but not too much).

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