Be sure to watch the tomatoes carefully so that you can remove them from heat if they start to burn or become too crispy.
The baking soda will fizz as it reacts with the acid of the tomatoes.
The seeds carry much of the acid content of the tomato plant, so removing them altogether is a great way to reduce the acidity. Some dishes are enhanced by cooking the seeds along with the flesh of the tomato, so take this into account before you remove the seeds.
You may have to get used to using tomatoes that are less cooked, but if you deal with problems stemming from acidic foods it may be worth the effort.
If a dish calls for you to simmer the ingredients for one hour, put the tomatoes in for the last 10 minutes. They’ll have time to warm up and soak into the dish a little bit, but not become overly acidic.
If you are putting the tomatoes into a hot dish, the other ingredients will most likely heat the tomatoes up enough to even out the temperature of the dish.
Heavier means more juice, which means more ripe. Tomatoes that are soft but not mushy are more ripe than hard tomatoes. You can also learn the smell of a ripe tomato versus the smell of an unripe tomato.
This is not a hard and fast rule as there are red varieties that are low-acid and non-red varieties that are high-acid. Some varieties to keep an eye out for are Yellow pear, a tomato similar to cherry varieties, Georgia Streak, a yellow heirloom variety, and Big Rainbow, a golden-red tomato.
