This recipe for tomato confit was passed down to me by my mother-in-law. Over the years these tomatoes have developed a reputation amongst our extended family and friends. I've yet to see a person try my mother in law's famous tomatoes and not love them and remember them.

The thing is - they just look like some cooked tomatoes in oil so you really don't expect much. At first glance they are… unassuming. And I've eaten my share of preserved tomato products. Sauces of course, but also preserved whole tomatoes - in vinegar, in brine, and yes, even in oil. Sun dried tomatoes too. None of them were anything to write home about.

But these tomatoes are something else entirely. When you take your first bite it's near life changing. Like you’re tasting the full potential of tomatoes for the first time.

In The Cooking of South-West France Paula Wolfert writes that confit can 'permanently enlarge your awareness of flavor.' From Coming of age; like a good wine, confit gets better and better over time - Molly O’Neill New York Times Feb 20 2000

They are sweet and savoury with an inkling of tang, elements of bold umami and mellow garlic, and a meaty caramelized texture. They have full depth of flavour and a buttery sticky-sweet mouthfeel. I've never tasted anything like them. You really just can't understand how good a tomato can taste until you try this method.

As any good recipe from a well-honed family matriarch, this one was transmitted to me not as a precise set of ingredients and directions, but more as a method and general quantities, the precise calibration of which I had to work out on my own. I've set out below everything I learned from my MIL and my own process so you can make your own batch at home.

Essential Elements of Tomato Confit

The essential elements of confit tomatoes are:

• cooking method: low and slow (around 120 - 150 C / 250 - 300 F for 4 - 6 hours)
• tomatoes: meaty ones, peeled, drained of liquid and salted
• oil: a generous amount
• additions: like garlic and herbs

Cooking method

In our family we don't use the term 'tomato confit' - we simply call these mom's tomatoes. It was only after I learned to make them myself that I clued in and realized that mom's tomatoes are part of a larger context: that of confit.

Confit means to cook something low and slow in oil as is the case for these tomatoes. These days in the English speaking world you're most likely to see confit on the menu of a high end restaurant. Or maybe a farm to table concept or gastropub. It has decidedly highbrown connotations which is funny because like so many delicacies, it was once simple peasant food borne more out of necessity than desire.

Another interesting modern-day twist is that the term "confit," originally a noun, is now used as a verb in modern English-speaking kitchens. "I'm going to confit this pork belly," or, "Let's serve those lambs' tongues confit'ed." You see confit on a menu? Chances are it has not been aged and stored under its fat or syrup for more than a few days. Heck, it may have been cooked just that morning. Michelin Guide Kitchen Language: What is confit?

While it might be an old technique and one developed out of necessity, confit still has a lot to offer modern cooks and it isn't limited to meat.

What is confit?

Confit is a very old method of food preservation that uses salt and fat to create an environment inhospitable to oxygen-dependant bacteria. Historically it was used primarily for the preservation of meat.

In ancient times, cooks from central Asia to western Europe learned that cooked meat could be preserved by burying it under a thick, airtight seal of fat. Today the best known version is the Southwest French confit of goose and duck legs, which became fashionable in the 19th century on the coattails of foie gras - which may in turn have been an accidental by-product of cramming geese to get the fat for unfashionable farmhouse confits! Harold McGee On Food & Cooking: The Science and Lore of the Kitchen

The confit method is best known in relation to its association with the cuisine of Southwestern France i.e. confit du canard or duck confit. Although these days we are much more familiar with duck confit, it was actually the goose variety (confit d'oie) that was more common in those times. In fact, Julia Child didn't even mention confit du canard in her famous tome Mastering the Art of French Cooking, while confit d'oie was treated in two separate instances.

Another element of confit that's just an important as salt and fat is that of time. Confit is known for a very low and slow process. The low and slow cooking process does several different things. When it comes to meat, it slows water evaporation and breaks down connective tissue, converting collagen into gelatin and producing juicy and succulent meat.

The low and slow process also gives the Maillard reaction more time to work it's magic. The Maillard reaction is responsible for a complex rearrangement of sugars and amino acids, which results in browning and flavour development.

The important thing about the Maillard reaction isn’t the color, it’s the flavors and aromas. Indeed, it should be called “the flavor reaction,” not the “browning reaction.” The molecules it produces provide the potent aromas responsible for the characteristic smells of roasting, baking, and frying. What begins as a simple reaction between amino acids and sugars quickly becomes very complicated: the molecules produced keep reacting in ever more complex ways that generate literally hundreds of various molecules. Most of these new molecules are produced in incredibly minute quantities, but that doesn’t mean they’re unimportant.  Modernist Cuisine The Maillard Reaction

The Maillard reaction is all around us, whether we're frying an egg or baking some cookies. The difference when it comes to confit is that the low and slow cooking process gives more time for increasingly complex flavours to develop, which results in a totally different experience than say pan fried duck leg. It's why searing versus braising a cut of beef produces different flavours.

Confit is to deep fat frying what barbecue is to grilling. Low and slow versus fast and furious. J. Kenji López-Alt The Food Lab at Serious Eats

Can you confit vegetables?

These days the word confit is used loosely to describe just about anything cooked slowly and gently to a rich, succulent consistency: onions in olive oil, for example, or shrimp cooked and stored under clarified butter. In fact the term is a fairly inclusive one. It comes via the French verb confire, from the Latin conficere, meaning ‘to do, to produce, to make, to prepare. Harold McGee On Food & Cooking: The Science and Lore of the Kitchen

The confit method has a lot to offer vegetables but it's a little different than for meat. For one, the primary reaction in meat is the Maillard reaction (which is related more to amino acids) whereas in vegetables it's caramelization (related more to sugars).

Caramelization may sometimes cause browning in the same foods in which the Maillard reaction occurs, but the two processes are distinct. They are both promoted by heating, but the Maillard reaction involves amino acids, as discussed above, whereas caramelization is simply the pyrolysis of certain sugars. Wikipedia Maillard reaction

Since vegetables contain both sugars and amino acids, the Maillard reaction still plays a role in cooking vegetables and the longer cooking time will yield more complex flavours. Caramelization also produces complex flavour compounds in vegetables like the Maillard reaction does.

Another effect of caramelization is that it forms new flavors, including flavors you might describe as buttery, or sweet, or nutty, or toasty. The Spruce Eats Caramelization: It's What Makes Food Turn Brown When You Cook It

Unlike low and slow cooking of meat where the flavour develops primarily from the Maillard reaction and the goal is to keep water in for juicy results, the caramelization of vegetables depends on getting the water out for maximum flavour development because "caramelization and browning can only happen in a dry-heat cooking environment" The Spruce Eats Caramelization: It's What Makes Food Turn Brown When You Cook It.

Thus when combined with low water content vegetables like roots, alliums and certain varieties of tomatoes, the low and slow cooking process of the confit technique allows time for maximum flavour development without overcooking.

That's the key difference between confit and other methods and why it makes such wildly flavourful tomatoes.

What vegetables can you confit?

Virtually any vegetable with low water content and a good level of sugar content can be 'confit'd'. Condiment confit is particularly well known in Italian cuisine - garlic, onions and chilis are the primary condiments. Potato confit is also well known in French and British cooking.

A few months ago I tried my hand at eggplant confit from Thomas Keller's Cooking Techniques Masterclass. One could also make a delicious confit with sweet root vegetables like carrots, parsnips, and beets. Other more adventurous options include  artichoke confit and leek confit.

In the last stage of caramelization, hundreds of new aromatic compounds form, creating a range of complex flavors. The result is a sweet, nutty, toasty flavor. Chowhound Why Roasting Makes Vegetables Taste Sweeter

Confit vs roasting?

The difference between confit and roasting is that confit takes place at lower temperatures for longer durations. Whether meat or veg, roasting is done at higher temperatures for shorter duration.

The exact temperatures that qualify as confit versus roasting vary depending on who you ask. Some will tell you that confit can only take place at temperatures below 100 C / 200 F while others will say 180 C / 350 F still qualifies.

From my experience there is no right answer and the exact temperature is less important than the time. The temperature is a function of what it produces. If the exterior browns quickly, it doesn't allow as much time for the complex flavours typifying the confit technique to develop. It's a trade-off. Roasting has its place but so too does confit.

It's also wise to note that the French peasants that first began developing confit from ancient preservation method to culinary technique likely did not have sophisticated temperature control ovens and may very well have been cooking with fire.

Confit vs sous vide?

There are a lot of similarities between sous vide and confit. Although confit is ancient and sous vide decidedly more modern, both involve 'low temperature long time (LTLT) cooking'. Likewise, both the Maillard reaction and caramelization can still takes place in sous vide as they do in confit.

The major difference between confit and sous vide is that sous vide involves sealing food in a plastic bag to retain juices and cooking in a water bath to maintain consistent temperatures. Obviously the results will just be different because the processes are different - but there are a lot of examples of modern day mashups like sous vide duck confit and sous vide caramelized onions. There are even people doing sous vide confit tomatoes.

Having not tried it myself I can't attest to the results. What I do know is that in general caramelization is most effective in dry heat, and since a sous vide bag would seal off tomatoes for example, it would seal in the juices which prevents further liquid evaporation. It stands to reason that this could reduce the impact of the caramelization process that is responsible for so much of the flavour development in confit vegetables.

Caramelization can only happen in dry heat, which means you can’t caramelize while steaming, blanching, boiling, or cooking with a sous vide machine. Bon Appetit What Does Caramelization Mean, Anyway?

Sous vide also won't create the same textural nuance as dry heat cooking does, which is why it's so common to sear off sous vide meat after the LTLT cooking. You could probably broil sous vide tomatoes to get a bit of true caramelization (i.e. not just browning but also drying out on the way to pyrolysis) but I haven't found any examples of this online.

What this means is that caramelization and browning can only happen in a dry-heat cooking environment. That is because the highest temperature water can reach is 212 F [100 C] and that's not hot enough to pyrolyze sugars or proteins. Thus, you can't caramelize anything by boiling it, simmering it, poaching it, or anything like that involves cooking it in liquid. The Spruce Eats Caramelization: It's What Makes Food Turn Brown When You Cook It

For now this is mostly conjecture but if you have any experience with this please do leave a comment below.

Essential elements: Tomatoes

Vegetables can also be preserved this way; confit garlic and tomatoes are upheld and celebrated by chefs far and wide. Michelin Guide Kitchen Language: What is confit?

What Type of Tomatoes for Tomato Confit?

Did you know that there are over 10,000 types of tomatoes? I'll never forget the first time I visited the Boqueria market in Barcelona and came across a stand specializing in tomatoes. I had never seen so many varieties in one spot. I was almost speechless and it was probably only about 40 varieties.

Tomatoes have many differentiating factors like size, shape, sweetness and water content. The best tomatoes for making tomato confit are tomatoes with thick walls, a meaty texture and very low water content.

Plum tomatoes are the winner

Plum tomatoes, the most common variety being the roma tomato, are the ideal tomato for making tomato confit. They are full of flavour, meaty, dry, and easy to drain of excess liquid.

Other varieties of plum tomatoes include San Marzano and Datterini (little date) varieties.

The thick-walled, oblong plum tomato is synonymous with Italy. Known in supermarkets primarily as Roma tomatoes, these big-sweet, big-acid tomatoes are known for their chewy flesh and low water content. A guide to tomatoes and the best use for each type The Seattle Times

Can I use cherry tomatoes?

Cherry tomatoes tend to have high water content and thin walls. They aren't ideal for confit according to the method outlined in this post.

There are a few examples of cherry tomato confit online including Cooking Light, The Petite Cook, and Baking the Goods. While I'm sure the final result is still tasty, these recipes differ in some key regards from the method in this post.

For one the cooking time is shorter (1.5 - 3 hours instead of 4 - 6 hours) because a thinner walled tomato can't hold up to longer cooking times. The tomatoes also aren't peeled or drained before cooking. The final photos show plump and round tomatoes that still have water content.

This is very different from the tomatoes in this post, which reduce for so long that very little water content remains resulting in a chewy and firm texture as well as deep and complex flavour.

It's like the difference between prosciutto and ham.

Can I use beefsteak tomatoes?

Beefsteak tomatoes are known for being meaty which is great for tomato confit but they also tend to be juicy which means higher water content.

There's a recipe by Saveur featuring confit beefsteak tomatoes. While they are peeled and cooked for just over 4 hours, they aren't drained before cooking. The final product looks like it contains more water than the tomatoes in this post.

In general beefsteak tomatoes aren't known for their low-water content like plum tomatoes are so if given the choice I would still choose plum tomatoes for tomato confit. If all you have are beefsteaks then your mileage may vary.

Can I use heirloom tomatoes?

The simplest answer is maybe. Heirloom doesn't refer to specific characteristics of the tomatoes but to specific characteristics of the growing process: namely the absence of cross-breeding and natural pollination by bees.

This means that heirloom actually refers to a variety of different types of tomatoes with different characteristics.

We love heirloom tomatoes for their idiosyncratic qualities. They often have have colors, textures, sizes, and flavors that vary from species to species, in the same way that apple varieties do. Bon Appetit What are heirloom tomatoes

Some heirloom tomatoes may be meaty and dry enough for confit, while others may not. If you can find plum or oblong shaped heirloom tomatoes then there's a good chance they'll be appropriate for tomato confit

What about other varieties of tomatoes?

In general you can use any variety of tomato that can be peeled and drained of excess liquid as shown below under preparation. Many tomatoes have too high a water content and do not have the structural integrity to stand up to peeling and draining. If you use those varieties of tomatoes you are likely to get a different result both in terms of texture and in terms of flavour.

Quantity of Tomatoes

I've found that 2 kg / 4.5 lbs of whole roma tomatoes will produce just about  1 litre jar 8/10ths full of tomato confit.

Preparation (How to Confit Tomatoes)

Preparing the tomatoes for confit is a bit labour intensive. In order to get maximum flavour development from caramelization and the Maillard reaction, the liquid in the tomatoes has to be removed as much as possible - just like one would pat dry meat to get a beautifully browned roast or pat dry potatoes for crispy fries.

One of the challenges to getting the Maillard reaction going is getting the surface hot and dry enough without overcooking the underlying flesh, or at least overcooking it as little as possible. Cooks have developed several strategies to this end, some simple and some fairly baroque. One strategy that works well is to remove as much water from the surface of the meat as possible before cooking it (via blotting or drying at low temperature). Modernist Cuisine The Maillard Reaction

First the tomatoes have to be washed, scored (cut two perpendicular lines across the stem), and blanched to remove the peels.

After the tomatoes are peeled, you'll need to cut each one lengthwise into halves or slices of consistent thickness approximately 2 cm / 1 inch thick - but you don't have to be too fussy about it. Then use your hands to gently squeeze out the excess liquid and seeds from the locular cavities (i.e. the tomato's inner compartments).

You could also cut the tomato width-wise. I've never tried it this way. Cutting lengthwise seems to make it simpler to squeeze out the excess liquid.

After the tomatoes are cut, line a sheet pan with an absorbent material like a clean kitchen cloth or paper towel. Liberally salt the tomatoes (about ¾ teaspoon per kilogram / 2 lbs of whole tomatoes) and let them sit and release more liquid while you prepare the oil and additions.

When the tomatoes are properly drained they should look like the photos above - empty crevices ready to be filled.

The Oil

Although goose and duck confit are known for being cooked and preserved in their own fat, vegetable confit generally relies on lighter oils. I've outlined some tips below for choosing an oil.

Type

A flavourless oil that is relatively inexpensive since you'll be using a lot of it. Good options include olive oil, avocado oil, sunflower oil, corn oil, and canola oil etc. Generally low smoke point oils are fine although finishing oils like flax, pumpkin and walnut, while flavourless, are also quite pricey so you may want to save them for other uses.

Quantity

About ½ to ⅔ of a cup of oil per 2kg of peeled and drained plum tomatoes. You may need more or less depending on the constitution of your tomatoes.

Additions

Salt: Salt is very important not only for flavour but also to help the tomatoes release their extra liquid as mentioned above. Use approximately ¾ of a teaspoon of sea salt for every 1 kilogram / 2 lbs of whole tomatoes.

Garlic: I like to use about 1 whole bulb of garlic per kilogram / 2 lbs of whole tomatoes. I've gone up to as many as 4 bulbs of garlic and while tasty, the smell in our apartment while slow cooking for 4+ hours became overbearing.

Fresh herbs: About 1-2 tablespoons chopped per kilogram / 2 lbs of whole tomatoes. Good options include oregano, basil, and thyme. Fresh herbs can be substituted for dry and vice versa.

Dry herbs: About 1 - 2 teaspoons of dry herbs per kilogram / 2 lbs of whole tomatoes. Good options again include oregano, basil, and thyme. Dry herbs can be substituted for fresh and vice versa.

Spices: This recipe doesn't include any dry spices but you can add spices as you wish and to your taste. A ½ a teaspoon of chilli flakes or a bit of dried fennel seed would be lovely.

Full process and ingredients: "the recipe"

Ingredients

Makes approximately a 1 litre of jar of tomato confit

• 2kg plum tomatoes like Roma
• 2 whole bulbs of garlic
• 1.5 - 2 teaspoons salt
• 1 tablespoon each fresh chopped oregano and basil
• 1 teaspoon dried thyme
• ⅔ cup olive oil

Equipment

• A large pot to boil water
• A large bowl filled with ice water
• 2-3 full size sheet pans lined with paper towel at first and then parchment paper or aluminium foil.

Process

• Preheat oven to 120 C / 250 F.
• Prepare the tomatoes: Bring a large pot of water to boil. Prepare a large bowl of ice water. Cut two perpendicular lines on the stem end of each tomato with a sharp knife. Drop each tomato in the boiling water for 15 - 20 seconds and then remove to the bowl of ice water. The skins should peel right off. If they don't blanche again. After blanching cut each tomato lengthwise into consistent slices approximately 2 cm / 1 inch thick and use your hands to gently squeeze out the excess liquid from the tomatoes. Line the sheet pans with clean dishcloths or paper towel and lay out the tomatoes. Salt them and leave them to release more liquid while you prepare the oil.
• Prepare the garlic & herb oil: Clean and mince or mash the garlic and add it to the oil along with any fresh chopped or dried herbs and spices you're using. Mix well with a spoon and let sit about 5 minutes.
• Stuff the tomatoes: Put the tomatoes in a bowl while you remove the wet dishcloths/paper towels and replace them with parchment paper. You could also use aluminium foil but it may stick. Use a spoon to stuff each tomato with the garlic and herb oil. If you run out, make another batch. Any extra can be stored in a jar in the fridge and used next time you make a roast or pasta for example.
• Cook the tomatoes: Start the tomatoes at 120 C / 250 F. Cook for about 2 hours and then check how far they've reduced and browned. If it seems to be taking too long, you can up the heat to 150 C / 250 F like I did. Cook between 4 - 6 hours until the tomatoes are reduced and caramelized.

Tomatoes are best stored in a large glass jar in the fridge and will keep up to 3 months. I use the Ikea Korken 1 litre glass jars.

A note on cooking temperature: I've found that a range between 120 - 150 C / 250 - 300 F for about 4 to 6 hours is ideal for these tomatoes. Being on the lower end of that range will slow down the process (6 hours) and being on the higher end will speed it up (4 hours).

Serving suggestions

Confit tomatoes are like a savory jam or chutney that is perfection served simply on bread, but if you manage to have any left, this confit can also make a beautiful addition to pasta, salad, sandwiches or dressed up more elaborately for a dinner party as a crostini appetizers with accoutrements like whipped ricotta and fresh basil.

Recipe