I’ve mostly cooked tomatoes on the stove, perhaps a few times on the grill but rarely in an oven, and probably not so for over a couple of hours. A friend of mine who likes to dry fruits and vegetables, sometimes in an oven and sometimes in a special dryer, said that even she hadn’t heard of slow-roasting tomatoes in the oven – it is not a common method but extracts and concentrates the flavor of the tomato in an uncommon manner.
In cooking tomatoes, some methods remove the skin and gel of seeds to obtain smoother texture and to reduce water; some methods use all of it; some modern methods use just the gel of seeds for its aesthetic appeal; and yet some methods cook the pulp separately from the gel of seeds, and then combine the extracts after filtering. The pulp contains most of the fruit sugars – which invariably gets used up the longer the tomato stays off the vine – while the gel of seeds contributes to the acidity1. Different varieties of tomatoes contain different proportions of sugar to acid, and in some southern states of North America and in parts of India even green unripe tomatoes are used in cooking.
Here’s a method to slow roast tomatoes in an oven:
Tomatoes – the best and freshest you can find.
Oil – light-bodied olive oil or any other similar oil.
Garlic (optional)
Thyme (optional)
Salt and pepper.
Wash and dry tomatoes, and cut them into halves before placing them in a single layer on a parchment-lined baking sheet. Grind garlic with oil and use the paste to coat the tomato halves generously. Sprinkle some thyme and season with salt and pepper. Place in a 250˚F oven and check every half hour or so. Depending on the size, water content, and number of tomatoes the roasting time might vary - adjust temperature accordingly. The tomatoes are considered done when they have shrunk in size, developed a deep brown to golden caramelized top, and still retain some moisture. Let the tomatoes cool-down before using them as is or skin removed to form the base of a sauce among other things.
It seems to be widely acknowledged that about 70 years ago people recognized and started to cultivate a variety of tomato that was uniformly red and regularly shaped unlike the older heirloom varieties that appear in different shades and irregular shapes. A botanist recently described how this recent variety that has become commercially popular arises due to a mutation that not only results in the observed traits but also reduces the sugar content by around 30% 2. The majority of sugar in tomatoes still arrives from photosynthesis that occurs in leaves2 making one think about the extent of flavor in vine-ripened tomatoes and vine-ripened heirloom tomatoes in particular.
Tomatoes are such an esteemed part of Italian cuisine that they are referred to as pomodoro or ‘golden fruit’. And, given the extent to which tomatoes are featured in this cuisine I would not have guessed that tomatoes in Italy were just a recent occurrence relative to the history of tomatoes. Tomatoes have been grown since many thousands of years in Central America but only in the 16th century were they imported to Europe where they were initially considered poisonous before being called the ‘love apple’ in English in the 18th century, and before returning to colonized North America to be used the way they were used in Europe3. How were tomatoes used in native Central American recipes ?
References:
1. On food and cooking by Harold McGhee.
2. How Tomatoes Lost Their Taste by Kai Kupferschmidt, News article in Science 28 June 2012, referring to the paper: Uniform ripening Encodes a Golden 2-like Transcription Factor Regulating Tomato Fruit Chloroplast Development by Powell ALT et al. Science 2012 Vol. 336 no. 6089 pp. 1711-1715.
3. Food: The history of taste edited by Paul Freedman
Beautiful colors and shapes. Almost every season growing up I looked forward to bringing home a few small tomato plants that mom would place in the backyard, sometimes with only a few small leaves dwarfed by their trellises, but we watched as they grew stronger and with excitement as the first delicate yellow flowers appeared. I was pleasantly surprised this year here in Baltimore by the appearance of a "volunteer" tomato plant in an abandoned pot of soil in my backyard, a seed that survived through the cold winter, now with its own cluster of ripening fruit. The birds have not been able to resist them, but if a few are left to share with me, perhaps I will try them roasted. 🙂
Thank you. I enjoyed reading your story of the tomato plant and the way you see things around you - I do wish the birds leave you some tomatoes!
Growing-up, I didn't spend much time watching plants though I used to listen to the excitement of growing them through my grandmother who was an avid gardener.
I recall your fascination with the tomatoes you had tasted in Israel - if you have the time I would love to hear about them sometime.
Hi Bala, I didn't know that tomatoes originated in Central America! I love slow roasted tomatoes and often use them in a composed salad with steamed asparagus and balsamic candied bacon.
Hi Sarah,
I did not know about the Central American origin of tomatoes either until recently. It appears that they may have been grown there since at least the seventh century AD, and so about a 1000 years before Europe saw tomatoes...
I'm going to try your salad idea, it sounds lovely - thank you.
Lovely recipe for roasting tomatoes and your history. Green tomatoes are used in indian cooking for their acidity and sour taste. I love using green tomatoes in a sambhar which adds a sour/sweet note to the lentils that rides on top of the tamarind flavor. Similarly I like green tomatoes with moong dhall which provide a sour note above the lentils.
Thank you. It has been very long since I've tasted green tomatoes in sambhar*, and I haven't tasted the dish with moong dhal** that sounds nice not to mention healthy. I will try to cook them if I find some good green tomatoes.
For the benefit of some readers:
*Sambhar is a south Indian sauce made from a base of lentils, a vegetable or two, tamarind and a custom blend of spices.
**Moong dhal is a type of Indian lentil or tiny bean that has a green skin.
Bala, nice to have a blog on gastronomy with posts containing scientific references. We can read the articles while eating these delicious tomatoes.....
Thank you, José. I look forward to hearing your perspective of gastronomy and science too...
Brings back memory of the terrace garden my dad prided. One day it would be only leaves well spread out in the crated wooden box which was used as a pot to hold the soil and the next day we would watch unripe green tomatoes often overlooked amidst the leaves unless carefully looked for. The next day would be like magic.Red tomatoes all over. What a fulfilling experience.
Since tomatoes are grown locally and are available through the year, used to using fresh tomatoes.in our day to day cooking. Grilled tomatoes are part of paneer tikka . Grilled after marinating in yogurt, ginger garlic paste, cumin powder,chilli powder and salt marinade. Is mouth watering.
Your recipe for slow oven roasted tomatoes is a must try. Sounds very interesting . You have posted great pictures.
Thank you. It is very nice to read your vivid recollections of your father's terrace garden, and specifically the tomato plants. I've never tried grilling tomatoes with the marinade you mention - it does sound delicious.