Slow Cooker Rosemary or Basil Infused Oil

My grandmother, Nonna Emilia, always had a small cruet of herb-infused oil on her kitchen counter. Its aroma – a heady mix of sun-drenched herbs and golden olive oil – was as much a part of her kitchen as the clatter of pots and pans. She drizzled it liberally over everything: crusty bread, ripe tomatoes, grilled vegetables, even a simple bowl of pasta. To me, that oil was the taste of home, a flavor I yearned to recreate.

Recipe Overview

• Prep Time: 5 minutes
• Cook Time: 1 1/2 to 2 hours
• Total Time: 1 hour 50 minutes to 2 hours 25 minutes (including cooling)
• Yields: 1 cup
• Dietary Type: Vegan, Gluten-Free, Dairy-Free

Ingredients

• 1 cup mild olive oil or 1 cup mild vegetable oil
• ¼ cup packed, chopped fresh rosemary leaves or ⅓-½ cup packed, roughly chopped fresh basil leaves

Equipment Needed

• Slow Cooker
• Sieve
• Clean Paper Towel or Paper Coffee Filter
• Metal Bowl
• Clean Glass Jar

Instructions

1. Begin by placing the oil and either the rosemary or basil into the insert of your slow cooker. The choice is yours! Rosemary provides a woody, earthy flavor, while basil offers a sweeter, more vibrant profile. Make sure the herbs are relatively dry before adding them to the oil to minimize splattering.

2. Cook the mixture on high, uncovered, for 1 ½ to 2 hours. The exact cooking time will depend on your slow cooker. You’ll know it’s ready when the herbs have infused the oil with their aroma and the oil itself shimmers with a subtle green hue. Keep a close eye on it during the last 30 minutes to prevent the herbs from burning.

3. Once the cooking time is complete, turn off the slow cooker and allow the oil to cool for about 20 minutes. This cooling period is crucial; it allows the flavors to meld and prevents you from burning yourself while straining.

4. After the oil has cooled slightly, pour it through a sieve lined with a clean paper towel or a paper coffee filter into a metal bowl. This process filters out the herbs, leaving you with a pure, infused oil. Don’t be tempted to skip this step – the small herb particles can make the oil cloudy and affect its shelf life.

5. Allow the oil to cool completely in the metal bowl. Once cooled, transfer it to a clean glass jar. A mason jar or a recycled olive oil bottle works perfectly.

6. Cover the jar tightly and refrigerate for up to 1 month. After that, the flavor may start to fade. The oil might cloud under refrigeration, which is perfectly normal. It will become clear again when brought to room temperature.

Expert Tips & Tricks

• Herb Quality: The fresher the herbs, the more intense the flavor of your infused oil. Whenever possible, use herbs from your garden or a local farmer’s market.
• Gentle Heat: While this recipe calls for cooking on high, keep a close eye on the oil. If you notice the herbs are starting to burn or the oil is smoking, reduce the heat to low.
• Strain Carefully: When straining the oil, avoid pressing down on the herbs in the sieve, as this can release bitter compounds into the oil.
• Flavor Enhancement: For an extra layer of flavor, try adding a clove or two of gently crushed garlic to the slow cooker along with the herbs and oil. Remove the garlic when you strain the oil.
• Spice it Up: Add a pinch of red pepper flakes for a little kick!

Serving & Storage Suggestions

This infused oil is incredibly versatile. Drizzle it over grilled vegetables, use it as a base for salad dressings, or brush it on grilled meats and fish. It’s also delicious with crusty bread or as a finishing touch to soups and stews.

To store, keep the infused oil refrigerated in a tightly sealed glass jar. It will last for up to one month. The oil may cloud or solidify in the refrigerator, but this doesn’t affect its quality. Simply bring it to room temperature to return it to its liquid state. Do not leave the oil at room temperature for extended periods, as this can encourage bacterial growth.

Nutritional Information

Nutrient	Amount per Serving (1 tbsp)	% Daily Value
Calories	120 kcal	6%
Total Fat	14g	22%
Saturated Fat	2g	10%
Monounsaturated Fat	10g	–
Polyunsaturated Fat	2g	–
Cholesterol	0mg	0%
Sodium	0mg	0%
Total Carbohydrate	0g	0%
Dietary Fiber	0g	0%
Sugars	0g	0%
Protein	0g	0%

Note: Nutritional information is an estimate and may vary based on specific ingredients used.

Variations & Substitutions

• Other Herbs: Experiment with other herbs, such as thyme, oregano, or sage.
• Citrus Infusion: Add strips of lemon or orange zest to the slow cooker for a citrus-infused oil. Be sure to use organic citrus and remove the white pith, as it can be bitter.
• Chili Infusion: For a spicy oil, add dried chili peppers to the slow cooker. Start with a small amount and adjust to your preference.
• Garlic Infusion: As mentioned before, garlic is a great addition. Gently crush a few cloves and add them to the oil.
• Seed Oils: While olive oil is classic, you can also use other mild-flavored oils like grapeseed or avocado oil.

FAQs (Frequently Asked Questions)

Q: Can I use dried herbs instead of fresh?
A: While fresh herbs are preferred for their vibrant flavor, you can use dried herbs in a pinch. Use about half the amount of dried herbs as you would fresh herbs.

Q: How do I know if the oil has gone bad?
A: If the oil smells rancid or off, or if it has an unusual appearance, it’s best to discard it.

Q: Can I use this oil for high-heat cooking?
A: While you can use this oil for cooking, it’s best suited for finishing dishes or for low-heat cooking, as the herbs can burn at high temperatures.

Q: Why does the oil get cloudy in the refrigerator?
A: Olive oil naturally contains waxes that solidify at cooler temperatures, causing it to become cloudy. This is perfectly normal and doesn’t affect the quality of the oil. It will clear up once it’s brought to room temperature.

Q: Can I use this oil for frying?
A: Due to the infused herbs, it’s not recommended to use this oil for deep frying, as the herbs can burn and impart a bitter taste. It’s better suited for drizzling and finishing dishes.

Final Thoughts

Creating your own infused oil is a simple yet rewarding culinary experience. The aroma that fills your kitchen as the herbs slowly release their fragrance is simply divine. I encourage you to experiment with different herbs and flavors to create your signature blend. Drizzle it generously, share it with friends, and let the taste of homemade goodness elevate your everyday meals. Don’t hesitate to leave a comment below sharing your favorite herb combinations or how you’ve used this recipe!