Heirloom tomatoes are varieties that have withstood the test of time. We have them today because seed has been saved and passed down through generations of growers. Heirlooms are almost as famous for being fickle in the garden as they are for great flavor. Generally they are lower yielding than modern hybrids. The thin skin that contributes to their flavor also means that they crack more easily than thicker skinned varieties. We look for the best of both worlds, and find heirlooms with the highest marketable yield without compromising on flavor.