Re bitter tomato sauce / purée / passata:
I tried the baking soda method, adding butter, and so on. Didn’t help much (and I can always taste baking soda so there’s that). I did strain out the seeds (and skin) finally.
I used a portion for an Indian chicken curry with plenty of spices, and cooked long - that worked well and the bitterness faded into the background.
Then we tried using it in a vegetarian curry which wasn’t cooked as long, and the bitterness was still very prevalent.
So - heavily spiced and long cooked seems to be the only salvage use (so far) for the bitter batch.
