Those so-called “fresh” tomatoes you buy at the grocery store have a lot to overcome. First, they are often picked green. Second, even though the label may say “vine-ripened”, that’s a stretch. Anyone who has grown their own tomatoes or purchased some from the farmer’s market during the summer knows there is a huge difference in flavor between naturally ripened and the almost ripe ones from the store.
And third, to top it off, some people make the mistake of putting the store-bought tomatoes in the refrigerator. And bye-bye goes the flavor.
So why do tomatoes lose their flavor when they are refrigerated?
According to Howard Hillman in his book The New Kitchen Science, tomato flavor comes from the natural conversion of linolenic acid to Z-3 hexenel molecules. The more Z-3 molecules the tomato has, the more flavorful and yummy it is. Cold temperatures (less than 55 degrees) hinders this conversion, and also reduces the ability for the Z-3 molecules to reach the olfactory receptors in our noses.
If you do happen to have refrigerated whole tomatoes, or have some you had cut into and wanted to save for another meal, Hillman says at the very least, bring the cold tomato to room temperature before serving. This may recover some of the flavor molecules.
Ideally, keep your store-bought tomatoes at room temperature for several days to develop the Z-3 molecules. When you treat tomatoes right, you may be pleasantly surprised at the improved tomato aroma and flavor, even in the middle of winter.