Fresh basil is one of summer’s most aromatic delights, but its tender leaves wilt quickly after harvesting. Canning basil allows you to capture its vibrant flavor and extend the season, infusing your pantry with homemade basil goodness all year round. In this guide, you’ll learn how to safely preserve basil for sauces, soups, and more, using tried-and-true canning methods that lock in freshness and taste.
Ingredients
- 4 cups packed fresh basil leaves (about 3 large bunches, stems removed)
- 2 cups water, divided
- 1/4 cup bottled lemon juice (for acidification)
- 1 teaspoon canning salt (optional, for flavor)
- 1 tablespoon extra-virgin olive oil (optional, for flavor and texture)
- Ice cubes (for blanching)
Instructions
- Prepare your canning equipment: Wash half-pint or pint canning jars, lids, and bands in hot soapy water. Place jars in a boiling-water canner or deep pot, cover with water, and bring to a simmer (do not boil). Keep lids and bands in hot, not boiling, water until ready to use.
- Blanch the basil: Bring 1 cup of the water to a boil in a large saucepan. Fill a large bowl with ice water. Working in batches, immerse basil leaves in the boiling water for 5-10 seconds, just until wilted and bright green. Use a slotted spoon to transfer immediately to the ice water to stop cooking. Drain and gently squeeze out excess water.
- Prepare the basil puree: In a blender or food processor, combine blanched basil, remaining 1 cup water, bottled lemon juice, and canning salt. Blend until very smooth. If desired, add olive oil and pulse to combine.
- Fill the jars: Remove hot jars from the canner and place on a towel. Ladle basil puree into jars, leaving 1/2 inch headspace. Wipe jar rims with a clean, damp cloth. Apply lids and screw bands on finger-tight.
- Process the jars: Place jars in a pressure canner (not a water bath, as basil is low acid). Add the recommended amount of water per your canner’s manual. Lock the lid, vent steam for 10 minutes, then process at 10 pounds pressure: 35 minutes for half-pint or pint jars (adjust for altitude as needed).
- Cool and store: Turn off heat and allow canner pressure to return to zero naturally. Remove jars carefully and cool undisturbed for 12-24 hours. Check seals. Label and store sealed jars in a cool, dark place. Refrigerate any unsealed jars and use within one week.
Tips
- Substitutions: If you run short on basil, you can blend in up to 1 cup of flat-leaf parsley without altering the flavor too much. Do not substitute fresh lemon juice for bottled; bottled ensures consistent acidity for safe canning.
- Storage: Only use jars with proper seals. If a jar does not seal, refrigerate and use within a week. Properly sealed jars last up to 12 months in a cool, dark pantry.
- Common mistakes: Do not use a water bath canner for basil puree—pressure canning is required for safety. Always remove as much air as possible from the puree to prevent discoloration.
- Flavor boosters: Add a clove of blanched garlic or a pinch of red pepper flakes when blending for a different flavor profile. Do not add cheese or nuts if planning to can; add those fresh when serving.
Serving Suggestions
- Stir a spoonful of canned basil puree into tomato sauce, soups, or stews for a burst of fresh herb flavor.
- Spread on toasted bread with a drizzle of olive oil for a quick bruschetta base.
- Mix into mayonnaise or yogurt for a herby sandwich spread or dip.
- Add to vinaigrettes, salad dressings, or pasta salads for a summery twist.
- Swirl into risotto or scrambled eggs for an aromatic finish.
Variations
- Basil-Garlic Puree: Add 2-3 cloves of blanched garlic to the blender for a savory, punchy version. Pressure can as directed.
- Spicy Basil Puree: Blend in 1-2 small blanched hot peppers (like jalapeño or serrano) for a kick. Always blanch and seed peppers before canning.
- Basil-Parsley Blend: Replace up to half the basil with Italian parsley for a milder, grassy flavor that’s great in soups.
- Lemon Basil Puree: Add the zest of one lemon (use only the zest, not fresh juice) for a bright, citrusy note.
- Roasted Basil Puree: Toss blanched basil with a tablespoon of olive oil and briefly roast at 350°F (175°C) for 5 minutes before pureeing, for a deeper, earthier flavor.
Storage and Reheating
Store sealed jars of canned basil puree in a cool, dark place (50-70°F/10-21°C) for up to 12 months. Check seals before use—if a lid flexes up and down, discard the contents. Once opened, refrigerate and use within one week. For best flavor and color, use within 6–8 months. If you wish to warm the puree before serving, spoon the amount you need into a small saucepan and heat gently over low heat, stirring frequently, until just warmed through. Do not boil, as this can dull the basil’s bright flavor and color.
Frequently Asked Questions
- Can I safely water bath can basil puree?
- No. Basil is a low-acid food and must be pressure canned to prevent the risk of botulism or other foodborne illnesses. Water bath canning is not safe for basil puree, even with added acid, as the puree’s density and pH can vary.
- Why do I need to use bottled lemon juice?
- Bottled lemon juice has a standardized acidity level, which is necessary to ensure a safe pH for canning. Fresh lemon juice can vary in acidity and may not provide enough acidification for safe storage.
- Can I add cheese or nuts to make pesto before canning?
- No. Dairy and nuts are not safe for home canning and can promote spoilage and bacterial growth. Always add cheese and nuts fresh when you open the jar and use the puree as a pesto base.
- How do I know if my canned basil has spoiled?
- Check for bulging lids, leaks, off smells, or mold. If a jar is unsealed or shows any sign of spoilage, discard it immediately. Never taste contents from a jar that appears spoiled.
- Can I freeze basil puree instead of canning?
- Yes! Basil puree freezes very well. Pour into ice cube trays, freeze until solid, then transfer cubes to a freezer bag. Use within 6 months for best flavor.
- What can I do if my basil puree turns brown?
- Basil can darken over time, even when canned. Blanching and acidification help preserve color, but some browning is natural and does not necessarily mean spoilage if the jar is sealed and smells fine. For the freshest color, use within the first 6 months.