A black tomato is a tomato variety whose skin turns deep purple, mahogany, or near-black due to high levels of anthocyanins, the same pigments that give blueberries, eggplant, and red cabbage their dark color. Despite the dramatic exterior, the flesh inside is typically red or dark red, and the taste is often described as richer and more complex than a standard red tomato. Black tomatoes aren’t genetically modified. Most come from traditional crossbreeding between cultivated tomatoes and wild species that naturally produce anthocyanins in their fruit.
What Makes Them Black
The dark color comes from anthocyanins, a family of plant pigments in the flavonoid group that produce red, blue, and purple hues across hundreds of fruits and vegetables. In standard red tomatoes, the color comes almost entirely from lycopene and carotenoids. Black tomatoes produce those same pigments in the flesh, but their skin also synthesizes anthocyanins, creating that distinctive dark overlay.
In the well-studied “Sun Black” tomato line, two specific anthocyanins account for most of the color: one called petanin (about 57% of total anthocyanins in the peel) and another called negretein (about 21%). The overall anthocyanin content in the skin is comparable to what you’d find in eggplant or red lettuce.
One important detail: anthocyanin production in these tomatoes is triggered by light. The parts of the fruit that face the sun develop the deepest color, while shaded areas, like the spot where the fruit rests against the stem or sits behind a leaf, often stay green or red. This is why black tomatoes grown in full sun tend to develop much more intense coloring than those in partial shade. UV radiation in particular activates the genes responsible for anthocyanin production, so sunny climates and exposed fruit produce the darkest results.
How They Were Developed
The most well-known black tomato bred for home gardeners is “Indigo Rose,” developed at Oregon State University through classical crossbreeding. Researchers crossed cultivated tomato varieties with wild species, particularly Solanum cheesmaniae, that naturally accumulate anthocyanins in their fruit. Through repeated selection over many generations, they stabilized the anthocyanin trait in a plant that still produces recognizable, tasty tomatoes. No genetic engineering was involved.
Many heirloom black tomatoes, like Black Krim and Cherokee Purple, predate this modern breeding work entirely. Their dark coloring comes from a different mechanism: mutations in carotenoid production and chlorophyll breakdown rather than high anthocyanin levels. These varieties tend to look more brownish-purple or chocolate-toned rather than the deep blue-black of anthocyanin-rich types like Indigo Rose.
Popular Varieties
Black tomatoes span a wide range of sizes, shapes, and exact shades. A few of the most commonly grown:
- Black Krim: A Russian heirloom beefsteak that’s dark red to purple-brown with olive-green shoulders that persist even when ripe. Fruits are round, ribbed, and average around 350 grams each. Known for a sweet, slightly smoky flavor.
- Cherokee Purple: Another heirloom beefsteak, originally from Tennessee, with a dusky rose-to-brown color and a reputation as one of the best-tasting tomatoes of any color. Rich, sweet, and low in acidity.
- Indigo Rose: The Oregon State variety, a smaller round tomato (closer to a plum tomato in size) with genuinely purple-black skin where the sun hits. The flesh is red and the flavor is mild.
- Black Cherry: A cherry tomato variety with deep mahogany to purple-brown skin. Prolific producer, sweet with a slight earthiness.
- Black Beauty: One of the darkest varieties available, with anthocyanin production so heavy that the entire fruit can turn nearly jet black. Medium-sized and round.
Flavor and Texture
Black tomatoes are generally described as having a more intense, complex flavor than standard red varieties. The taste tends to be sweet but balanced by a mild acidity, with a slightly salty quality that’s unusual for tomatoes. Many gardeners and chefs describe notes that are smoky or earthy, though the exact profile varies significantly by variety. Black Krim leans sweet and rich, while Indigo Rose is milder and more straightforward.
The texture of most heirloom black tomatoes is softer and juicier than grocery-store reds, with thinner skin. This makes them excellent for slicing and eating fresh but less ideal for shipping, which is one reason you rarely see them in supermarkets. They bruise easily and have a shorter shelf life than firmer commercial varieties.
Nutritional Differences
The anthocyanins in black tomato skin are potent antioxidants, which is the primary nutritional advantage over red tomatoes. These are the same compounds studied extensively in blueberries and other deeply pigmented produce for their potential role in reducing inflammation and protecting cells from oxidative damage.
Red tomatoes still win on lycopene, the antioxidant most associated with tomato health benefits. In cherry tomato comparisons, red varieties contained about 48 mg/kg of lycopene versus roughly 34 mg/kg in darker-colored types, a difference of nearly 50%. Flavonoid levels, however, tend to run slightly higher in darker varieties. Vitamin C content varies more by growing conditions than by color alone, though some dark cherry tomatoes have tested higher than red ones.
The practical takeaway: black tomatoes offer a different antioxidant profile rather than a universally superior one. If you eat both, you’re covering more ground than eating either alone.
Growing Black Tomatoes
Black tomatoes grow in the same conditions as any other tomato: warm soil, full sun, consistent water, and support for the vines. The one difference that matters is sunlight. Because anthocyanin production depends on light exposure, maximizing sun contact directly affects how dark the fruit gets. Pruning excess foliage to expose developing fruit can make a noticeable difference in color intensity.
Cool nighttime temperatures also promote anthocyanin development. Gardeners in climates with warm days and cool nights (below about 15°C at night) often report the deepest coloring. In hot, humid climates where nighttime temperatures stay high, the purple or black tones may be less dramatic.
How to Tell When They’re Ripe
This is the biggest practical challenge with black tomatoes. You can’t rely on color changes the way you would with a red tomato, because the fruit is already dark long before it’s ready to pick. Two reliable indicators: first, a ripe black tomato will give slightly when you squeeze it gently, similar to a ripe peach. Second, many black varieties develop a small star-shaped pattern at the stem end of the fruit when they’re ready. The bottom of the fruit (the blossom end) often shifts from a hard green or purple to a softer red or brownish-red as ripeness approaches. When in doubt, a gentle squeeze is the most reliable test.