Q Can you recommend a foolproof recipe for canning ratatouille? There seems to be differing points of view regarding its advisability. I have a pressure canner and would love to have ratatouille in the winter. Items to consider are: Should it be canned raw or previously cooked? If cooked, would canning reduce it to mush? Are there vegetables that should not be included? I don't like peppers or mushrooms, so omitting them is fine with me, but what about eggplant?
Anne AAnne's question was sent in late summer, when farm markets were bursting with local produce, and she wanted to can some for later use. Because other questions were in the queue, I'm just getting to hers now, but B.C. produce she could use for ratatouille is still available at some supermarkets.
Ratatouille is believed to have originated in the Provence region of France. Several sources said the word is derived from the French word "touiller," which means to stir.
It's typically made by cooking eggplant, tomatoes, onions, bell peppers, zucchini, garlic and herbs in olive oil. According to the New Food Lover's Companion, the vegetables used can vary according to the cook.
That answers Anne's questions about leaving out the peppers, although they, like eggplant, can be canned.
I could only find one credible recipe for canning ratatouille and used it as a guide for today's recipe. It's from CanningUSA.com.
Because ratatouille is made from low-acid vegetables, Anne will need to use her pressure canner, a pot with a locking lid, pressure gauge and steam vent.
According to canning manufacturer Bernardin's website, bernardin.ca, the growth of clostridium botulinum spores, which cause botulism, is prevented when jars of low acid foods are heat-processed at 240 F (116 C) for the prescribed time.
Low-acid foods cannot be heat-processed in a boiling water canner, as it heats to only 212 F (100C).
Anne asked if the ratatouille should be raw or cooked when canned. To me, it's not ratatouille if the vegetables aren't first simmered in olive oil. For canning, however, I would undercook the vegetables, not stew until tender as called for in many recipes.
When complete and ready to open, my canned ratatouille looked similar to fresh-cooked. Texturally, though, it was much softer and its taste nowhere near as robust. That's not surprising as the CanningUSA.com recipe said the jars had to be heatprocessed for 90 minutes.
When researching this story, several sources said you could also freeze ratatouille, which I tried. When reheated, you could tell it had been frozen, but its texture and colour was much better than canned. To give Anne three options, my recipe allows her to eat the ratatouille right after cooking, or freeze or can it for later use. The technique and some of the instructions on pressure canning came from bernardin.ca and CanningUSA.com, two websites home-canners should visit.
RATATOUILLE - FRESH, CANNED OR FROZEN
Use only the best looking and tasting ingredients to make ratatouille. If the vegetables are withered and tasteless, your ratatouille will have the same qualities. Wash and dry vegetables before using. This recipe can be expanded.
Preparation time: 20 minutes (plus canning or freezing time for those methods) Cooking time: Depends on technique used, see method Makes: 4 cups
2 small eggplant, unpeeled, cut into 1/2-inch cubes
5 Tbsp olive oil
4 medium, ripe, on-the-vine tomatoes
1 medium onion, diced
2 garlic cloves, minced
1 medium zucchini, cut into 1/2inch cubes
2 tsp herbs de Provence (see Note)
1/2 tsp salt, or to taste
1/2 tsp freshly ground black pepper, or to taste
2 Tbsp lemon juice
Preheat the oven to 375 F. Place the eggplant on a parchment paper-lined baking sheet and toss with 2 Tbsp of the olive oil. Roast 30 minutes, or until tender. Remove from oven and set aside.
Coarsely chop the tomatoes and place them and any juices on the board in a bowl. Heat the remaining oil in a wide pot set over medium heat. Add the onion and garlic and cook 5 minutes. Add the tomatoes, zucchini and herbs. Bring to a gentle simmer; simmer 15 to 20 minutes. Mix in the roasted eggplant, lemon juice, salt and pepper.
If canning or freezing, remove from the heat and follow the instructions below. If eating now, simmer the ratatouille 10 or so minutes longer, until the desired texture is achieved.
Cool to room temperature, and then divide among shallow, airtight containers or freezer bags. Label, date and freeze for up to three months. Thaw and reheat when needed.
Place rack in pressure canner and add about 3 inches water.
Place 4, 1-cup (250-mL) canning jars in the canner. Heat water to a gentle boil. Set screw bands aside; heat snap-top lids in hot water (180 F/82 C). Keep lids hot until ready to use.
Remove and fill the hot jars with the ratatouille, leaving 1-inch of headspace. Wipe the rims clean. Centre the snap-top lids on the jars. Apply the screw bands.
Screw band down until resistance is met, then increase to fingertip tight. Return filled jars to canner. Make sure the water level in canner is about 3 inches; or the level recommended in your pressure canner manufacturer's manual.
Lock canner lid in place, leaving vent open. Place the canner over high heat and allow steam to escape steadily for 10 minutes, venting canner.
CanningUSA.com says to now process ratatouille for 90 minutes at 11 pounds, or 10 pounds for a weighted gauge. (For elevations above 300 metres, check CanningUSA.com's guide for altitude adjustments.)
When processing time is complete, remove canner from heat and let stand undisturbed until pressure drops to zero.
When it's there, or when no steam escapes when the canner's weight is nudged, wait 2 minutes, and then remove the cover, tilting it away from you. Remove jars and set on a protected surface in a draft-free place to cool. Do not tighten screw bands. Cool undisturbed for 24 hours. Check jar seals by pressing on the centre of each lid. If the lid centre is pulled down and does not move, remove the screw band and lift the jar by the lid. Lids that do not flex and cannot be easily lifted off the jars have good seals.
Refrigerate or reprocess any unsealed jars. Wipe jars with a damp cloth. Remove, wash and dry screw bands; store separately or replace loosely on jars, as desired. Label and store jars in a cool, dark place. Use within a year.
Eric Akis is the author of the bestselling Everyone Can Cook series of cookbooks. His columns appear in the Life section Wednesday and Sunday.