Tomatoes are clearly a fruit, botanically. In culinary practice they are a vegetable (botany doesn't define "vegetable", so botanists can't complain about this). In 1893 the US Supreme Court ruled that tomatoes are a vegetable and the US Department of Agriculture classifies them as such.
The wild ancestor of domesticated tomatoes is native to Peru and Ecuador, They were grown as a crop in both areas by 500 BCE and probably a lot earlier.
The Spanish took tomatoes to the Philippines, from where they spread to Southeast Asia. They also took them to the Caribbean and to Spain, where cultivation began in about 1540. From there they spread to Italy. Some of these early varieties were yellow or orange, resulting in the name "golden apples" in several languages.
When I was in elementary school in New Jersey, our teachers told us Europeans were so ignorant they thought tomatoes were poisonous. They were far less ignorant than our teachers, immediately recognizing tomatoes as a close relative of the sometimes deadly Black Nightshade. That didn't stop them from eating them though. By 1544 they were described as edible and as "a new variety of eggplant" (another nightshade berry that was initially suspect). Americans were more ignorant, though, and didn't accept tomatoes as edible until about 1850.
Early tomato sauces were simmered for a long time because that's how Europeans were accustomed to detoxifying Black Nightshade berries for use in pies. Today we know the tomato berry is not toxic (though the rest of the plant is mildly toxic), and tomato sauces may be short cooked or even raw - unless you subscribe to Michio Kushi's Macrobiotics theories which hold them to be so toxic that I must have died decades ago from eating so many of them.
Tomatoes are plentiful now but flavor has been developed out of commercial varieties. While agricultural colleges and industrial farms concentrated on durability, mechanical picking and shelf life, without regard to flavor, the real culprit was appearance. In the '50s, a variety was found with a genetic trait that caused it to ripen evenly, rather than being green on top.
This even ripening trait was bred into almost all commercial tomato varieties. It has recently been found that this trait also suppresses sweetness and other flavoring traits. The only way to get really tasty tomatoes is to grow heirloom varieties yourself, or buy them from small growers at farmer's markets. Tomato developers are attempting to get the flavor back in without sacrificing even ripening, but say it's a very difficult task.
In Florida, powerful (read: "big political contributors") tomato growers have conspired to prevent competition from more flavorful Mexican tomatoes. Their politician pals have been happy to help with legislation (like packaging laws that guarantee ripe tomatoes will be crushed). To quote the head of a big Florida grower, "Who cares about flavor in tomatoes, they're always served with something else" (Wall Street Journal article back in the early '80s).
In the United States, California and Florida dominate the fresh tomato
market, split about even. In addition, California produces about 90% of
all tomatoes used for canning and processing, while Florida grows almost
none for that purpose. Mexico is the main competitor to both states, but
other states produce modest amounts, mostly for processing.
Recipes routinely call out for a "medium" or "large" tomatoes, without any hint about size or weight - except English cookbooks which just call for "1 Tomato" with no hint whatever as to how much "1 Tomato" weighs in London. This table is based on tomatoes grown in California and Mexico, which supply most of North America's tomatoes.
All domesticated tomatoes belong to a single species, Solanum lycopersicum, a member of the Solanum branch of the Solanaceae or Nightshade Family. Wild tomatoes belong to different species, but cross breeding is still possible.
Current Tomato -
This wild tomato is considered to be the ancestor of the
domesticated tomato. It is native to Ecuador and Peru, but has been
introduced elsewhere. It's berries are edible and it is often grown as
an heirloom tomato, though still considered wild. It crosses freely
with domesticated tomatoes, and is very important to breeding tomato
cultivars, espeically for disease resistance, as the gene pool of the
domesticated tomato is rather shallow.
Photo by KENPEI distributed under license Creative
Attribution-ShareAlike v3.0 Unported.
Galapagos Tomato -
This wild tomato is native to the Galapagos Islands, where it
developed in isolation. Both its foliage and fruit are a paler color than
its nearest relative, the Current Tomato, but the fruit still tastes like
tomatoes, and is edible.
Photo by Kevin Gepford distributed under license Creative
Attribution-ShareAlike v4.0 International.
Varieties - Domesticated
Colors of Tomatoes
For a while these were hailed as the savior of flavor in commercial
tomatoes, but the tomato industry quickly learned how to make flavorless
cherry tomatoes. They are still usually more flavorful than Mass Market
Tomatoes, but the Grape Tomato has overtaken them in the markets. They
are usually a two chamber fruit (as shown in photo), but sometimes three
chambers. For salads, I usually cut them once crosswise if small, and
the halves once lengthwise if large.
The claim is that cluster tomatoes, left on the stem, will continue to
draw nourishment and will ripen better, but this amounts to yet another
hoax put over on the wannabe gourmets. Nothing can fix a hothouse
tomato. Stick to the small ones, or even good quality field grown
Mass Market tomatoes left out on the counter to ripen for about 4 days.
Clusters are not waxed, so they dehydrate quickly and you should plan
on using them up within 2 or 3 days.
These are an example of what commercial tomatoes could be. They show
up in one of the produce markets I shop at around September, but I
suspect most go to the fancy restaurant trade. They are picked quite
ripe, are large, thin skinned, juicy, sliceable and have excellent
tomato flavor. Of course, ripe, juicy and thin skinned means they
cannot survive the rough handling most commercial tomatoes suffer.
The one to the left in the photo was 3-7/8 inches diameter, 3 inches
high and weighed 13-7/8 ounces. They were purchased from a large
multi-ethnic market in Los Angeles (Sunland) for 2016 US $0.99 / pound.
Grape Tomatoes -
These tomatoes have become much more common than Cherry Tomatoes here in Southern California. Buy them from a bin if you can, so you can check firmness. If they are at all soft, they will be inferior in flavor and texture. Most sold are red, but yellow and orange varieties are also available. Some varieties are exceptionally sweet and tasty, others are purely decorative, having almost no flavor. In general, yellow ones have the least flavor and red ones have the most, with orange ones in between.
These tomatoes are usually "two chambered" (see example to the left
in photo). I usually cut them in half crosswise for use in salads. They
are usually up to 1-1/4 inch long, 7/8 inch diameter and weigh about 6
to the ounce (20/100 grams). The medium regular tomato in the photo
weighed 6-1/4 ounces.
Green tomatoes were thought to contain significant amounts of
solanine neurotoxins, but this is not well supported in medical
literature. They do contain the much less dangerous alkaloid tomatine,
but there are no reports of persons harmed.
Green Zebra Tomatoes
Most "heirloom" tomatoes are not actually older varieties, but recently developed varieties that imitate them - and may or may not have been developed from older varieties. The main requirements are better flavor, odd colors, weird shapes and maybe a few healed cracks.
According to the Los Angeles Times (07-2004), supermarket growers had
noticed a market for "heirloom" tomatoes, and by 2006 some supermarkets
were selling Copia and Costoluto Genovese for 2006 US $7.00 / pound.
These are very striking in appearance, but are more suitable for tomato
sauces and tomato paste than for salads and general eating.
Heirloom Cherry Tomatoes
Supermarket chains post absurd prices for these, but their flavor
will not improve much even set out on the counter for a few days. That
is not to say they don't have uses - let them sit until they're really
soft and use them to pelt politicians. The photo specimens were
purchased from a big multi-ethnic market in Los Angeles (Sunland)
which always has them, probably the ones that weren't perfect enough
for Gelson's, and sells them for 2016 US $0.99 / pound.
Mass Market Tomatoes -
Standard supermarket tomato varieties like "Red Rock" were developed by agricultural researchers to withstand machine picking, rough handling, long transportation, and still look pretty. They paid no attention to flavor, admitting they thought that would take care of itself. They've recently discovered that the genetic trait that causes even ripening, now incorporated in most market varieties, is also a trait that robs tomatoes of sweetness and flavor.
Due to consumer complaints, there is now (2012) significant development effort devoted to flavor, but the problem is complex and commercial results are expected to come slowly. I've seen some improvement here in California, and I see more varieties that don't ripen evenly, but they are still often picked too green and remain whitish inside. The situation may be much worse in Florida, where the president of a huge tomato grower made this statement to the Wall Street Journal, "Who cares if a tomato has any flavor, it's always served with something else".
Select good quality Market Tomatoes that are firm and without bruises or soft spots. If possible, sample them before buying many, different batches from the same vendor are often quite different. They should be quite juicy with big seed cavities full of liquid rather than solid with small or dry cavities.
You're better off with a touch of green at the stem end than over-ripe, and avoid those with a uniform pale pink color. Set them out on a non-porous shelf or counter out of direct sunlight for a few days and you'll have tomatoes much better than expensive Hothouse Tomatoes. I buy them from a high volume produce store and select various stages of ripening for a steady supply.
Mass Market Tomatoes are always thinly coated with an edible wax to
give them better shelf life, and I've had some last over a month sitting
on the counter, until all the seeds inside were sprouted and trying to
burst through the skin. Tomato sprouts contain a small amount of toxin
to which some people are sensitive. I've sampled tomatoes with sprouted
seeds without ill effect, but the flavor will have both changed and
Not a tomato but a Physalis, see Tomatillo.
[Italian Plum Tomatoes]
Romas are small elongated tomatoes, which may be pear shaped or heart shaped, typically 2-3/4 inches long and 1-1/4 inch diameter, weighing about 3 ounces. Generally they are red, but occasionally yellow or orange are available, but these have less intense tomato flavor. Roma tomatoes are often canned with a bit of Basil. They are preferred for Italian sauces and much other cooking because they have a high percentage of solids and little juice - which means they aren't that good for eating raw or for salads, but they still may be better than poorly ripened regular tomatoes.
Romas are quite sturdy ripe, and since they're expected to be cooked
they are often picked riper than Mass Market Tomatoes, which can give
them better flavor for cooking. To peel, give them a little longer in
boiling water (1-1/2 minutes total) than for most tomatoes.
Roso Bruno Tomato -
[Brown Tomato, Kumato (original name)]
This is a patented variety grown by Dulcinea Farms in California. The San José Mercury News called them a "New Taste Sensation" and worth ever bit of the US 2006 $3.99 / pound they were selling for up there in Yuppyville. My local produce market in Los Angeles (Sunland) was selling them then for between $.69 and $.89/pound. Of course showing off to your friends that you paid just $3.99/pound for hyped tomatoes may be an important consideration in San José.
So how do they taste? Pretty decent for hothouse tomatoes, but there's
only so good hothouse tomatoes get. Leave good quality field grown Mass
Market Tomatoes on the counter to ripen for a few days and you can beat
the flavor. They have to be grown in hothouses because of the patent
nonsense. By now (2016) they seem to have disappeared from the general
market here in Southern California - I haven't seen one for years -
color it passé.
San Marzano Mini Plum Tomatoes
Grown specially for the Yuppie market, these have little to recommend
them except the prestigious Italian name and unusual shape. They are
drier, fleshier and less flavorful than regular California Grape or
Cherry Tomatoes. They are up to 1-7/8 inches long and 7/8 inch diameter
at the widest part, weighing a little over 2.2 to the ounce. The photo
specimens were hothouse grown in Canada and distributed by Trader Joe's
at 2016 US $4.46 / pound. The photo also includes a regular medium
tomato weighing 6-1/4 ounces, sold for $0.99 / pound.
Seeds of this variety are reported to have been developed in Russia,
and introduced to Canada in 1975, spreading from there. These tomatoes
are not grown commercially, but seeds are widely available for home
gardeners. They are valued for being a very early variety which can set
fruit at as low as 38°F/3.3°C, and having a 50 day seedling to
fruit time. They are not, however, much more frost tolerant than other
tomato plants. They are a very early tomato in frost free parts of
California. They are small, up to about 5 ounces and 2-1/2 inches
Photo "borrowed" from
Seed Savers Exchange, which has
seeds for sale.
Not a tomato but a Physalis, see Tomatillo.
In some parts of North America, canned tomatoes are the only way you can get enough tomato flavor to make a decent tomato sauce. Even in better regions, or for home growers, it's needed in the off season. Canners can pick tomatoes when they are truly ripe, since they will be processed immediately - and they need to pick them fully ripe, because they compete only on flavor and price. One can looks pretty much like any other can. I have found some of the "no-name" brands can be as good as or better than the "big name" brands. Canned tomato products are usually in 14-1/2 ounce, 28 ounce and 5.5 pound cans.
These products contain only tomatoes, salt and occasionally a basil leaf or two. For making sauces, the farther down the list from Whole Canned Tomatoes you go, the more sauce a can will make, but the flavor will be increasingly darker and it will splatter more during cooking.
Stewed Tomatoes: These are sliced tomatoes (half way between whole and diced) with flavoring ingredients similar to those in a simple Tomato Sauce, but often way too much of it. They are packed in tomato juice. You're a lot better off starting with whole canned tomatoes, cutting them into chunks and adding your own seasonings.
This product comes in many varieties. The simplest canned sauces generally contain tomato purée, salt, onion powder, garlic powder, citric acid, dehydrated bell pepper, and some spices, but have very simple tomatoey flavors. You should always have a simple sauce like this on hand, in small 8 ounce cans. It's a very handy recipe ingredient. My usual brand is Faron "Spanish Style" (in in the photo). If I don't use a whole can I freeze it the same as for tomato paste (see above). Actually, I often use it in place of tomato paste, using about twice as much.
There are many much more complex "Gourmet" sauces on the market, but
I never use them. It's just way too easy to make better sauces starting
with canned tomatoes. Many claim to be "Italian", but are really
"Italian American", a cuisine despised by real Italians. Some of the
commercial sauces have an angry flavor, and most will splatter badly
when heated. "Gourmet" tomato sauces can contain just about anything,
so long as tomatoes are a major ingredient.
Sun Dried Tomatoes
Long a specialty of Italy, sun dried tomatoes were made for use during the off-season, and are now called for in many Mediterranean recipes. Originally, tomatoes were sliced and set out in the sun on slanted boards. The boards were brought in at night and put out the next morning until the tomatoes reached the right state of dryness. Then they would be packed in olive oil.
Today, more efficient methods are used but the basics are still the same - and some are now available without the olive oil. The photo specimen is from Trader Joe's - no country of origin, so it's pretty certain it wasn't Italy. Due to similarity with some other products, I suspect it was from Fresno. Ingred: Sun Dried Roma Tomatoes, Pure Olive Oil, Garlic, Herbs, Spices, Sulphur Dioxide (for color retention). In my opinion, the Garlic, Herbs and Spices pretty much overwhelm the tomato flavor in this product.
The photo specimens were sliced Roma tomatoes dried in a home type
electric dehydrator at 114°F/46°C. They dried quite quickly,
with 14 ounces of raw tomatoes, end slices discarded, becoming 5/8
ounces dried (4.5%). With a slightly leathery "snack chip" texture, they
had good concentrated tomato flavor and bright red color.
Ketchup is held in high favor by children, because it has more sugar
than ice cream - it's sort of tomato flavored candy. By federal law,
if your product doesn't have that much sugar it can't be called
"ketchup". This was a ploy by the food industry to "standardize" the
product so they didn't have to reveal on the label that it was about
1/3 sugar (other ingredients are water, salt, vinegar, spices, and, yes,
tomatoes). For details see our
Tomato Ketchup page.
Followers of Michio Kushi's Macrobiotic movement condemn tomatoes as dangerously toxic and highly destructive to the human organism (along with potatoes, eggplants, chilis and tropical fruit). Since I eat vast amounts of fresh tomatoes, (raw, with Sukang Iloco vinegar and a little salt), tomato sauces, and recipes with plenty of tomatoes in them, I should at least be on my deathbed by now.
Of course, you don't want to eat a lot of green tomatoes that aren't well cooked, or any of the foliage, as these contain toxins to which some people are quite sensitive.
Tomatoes contain the important antioxidant Licopene, and are by far the richest source of Licopene in the American diet (Gac fruit has a lot more, but try finding that at your local market). This antioxidant has been shown to contribute to resistance to some cancers (including prostate cancer), heart disease, osteoporosis and decline in cognitive function with age. Cooking tomatoes increases the amount and bio-availability of licopene.
Tomatoes also contain plenty of vitamin C and A, and are quite high in potassium - more than bananas. Potassium helps lower blood pressure and counters the ill effects of excessive sodium.
Green tomatoes, seed sprouts and foliage were said to contain significant amounts of the neurotoxin solanine, but this is not well supported by medical literature. I've eaten modest amounts of green tomatoes raw without any ill effects.