Summer is heating up and so is the craving for the mouthwatering taste of a juicy vine-ripened tomato. Before the age of supermarkets, most people had summer gardens in which tomatoes were considered royalty. Prized tomato seeds were handed down in families, and a delicious sun-ripened tomato was taken for granted.

With the advent of commercial farming and shipping across the country, tomatoes had to be hybridized to withstand handling. Grocery-store customers began to count on good-looking tomatoes that came with thick skins, a mealy texture, and not much taste. But all had not been lost. The Slow Food Movement was founded, and part of its mission was to prevent the annihilation of thousands of food varieties and flavors. Heirloom seeds were a part of this preservation effort, and today, in most local farmers' markets and specialty grocery stores, you can find delicious heirloom tomatoes that taste like you remember.

Tomato plants or any vegetable or fruit grown from heirloom seeds is open-pollinated and not manipulated to produce specific traits, such as a thicker skin, a certain size, or a kind of texture. According to Taylor's Guide to Heirloom Vegetables, a tomato must meet three criteria to be considered an heirloom variety: The variety must grow from seed saved from each fruit, seed must have been available for more than 50 years, and the tomato variety must have a history or folklore of its own. There are literally thousands of heirloom varieties from all over the world. Typically heirloom tomatoes are available vine ripened and thus are not suitable for shipping because they're too perishable.

Although most heirloom tomatoes are prized for their taste, they're often chosen for use in recipes because of the variety of colors. Besides the typical reds, these include pink, orange, yellow, green, purple, black, and white. Compared with the perfectly shaped grocery store varieties, these special tomatoes may be misshapen, and they may even have splits in the skin.

Although growing your own heirloom tomatoes can become a passion, you can often buy them from local farmers' markets. Try substituting heirloom tomatoes in recipes that can highlight their vibrant taste and beautiful colors.

Follow these step-by-step instructions to make Spinach Stuffed Tomatoes