Do tomato seeds turn fresh tomato sauce bitter?
Many recipes for tomato sauce call for first seeding the tomatoes, a process that can be a chore for large batches. To see if skipping this step would leave us with a bitter sauce, we compared a batch of tomato sauce in which we had seeded beefsteak tomatoes with one in which we hadn’t. In the past, we’ve found that the gel surrounding the seeds is rich in savory glutamates (more glutamates, even, than the flesh of the tomato), so we pushed the guts from the seeded tomatoes through a fine-mesh strainer, ensuring that only the seeds were left behind and preserving the gel. Out of curiosity, we sampled the raw seeds straight up and found them to be completely benign.
Forty minutes of simmering in the sauce didn’t change a thing; our tasters still detected no bitterness in the tomatoes and in fact found the sauces identical in flavor. Since the seeds don’t harm the flavor and removing them is a hassle, we’ll be leaving them in. If you choose to remove the seeds for aesthetic reasons, be sure to strain off and use the flavorful gel that surrounds them.