Basil-Infused Olive Oil (Simple Recipe)

Blend 1 packed cup of washed, thoroughly dried basil leaves with ½ cup of unheated olive oil until smooth. For a brighter green color, blanch the basil for 10 seconds, then cool it in ice water and dry it well. Serve the oil fresh, or refrigerate it promptly at 4°C / 40°F or below and use within 4 days.

Before, a handful of basil can seem like an easy way to make a flavorful oil, yet wet leaves may leave it dull and watery, and a jar on the counter can create a safety risk. After, the leaves are dry, the oil is blended without heat, and you know how to serve or store it safely. I use this same simple sequence when teaching cooks how to get a vivid, fresh-tasting finish without turning a quick recipe into a preservation project.

Equipment, Basil Preparation & Food-Safety Setup

This is a fresh herb sauce, not a preserved oil. Use clean, nonreactive equipment such as stainless steel, glass, or food-grade plastic, and keep the oil unheated. The finished oil needs prompt refrigeration and a short storage time because fresh basil adds moisture to the mixture.

What you need

For one small batch, gather:

• 1 packed cup fresh basil leaves
• ½ cup olive oil, preferably extra-virgin
• A blender
• A clean bowl for an optional ice bath
• A clean, dry, covered container
• A fine sieve, only if you want to strain the oil

“Packed cup” means gently filling a measuring cup with leaves, without crushing or pressing them hard. The starting ratio makes a thick, spoonable sauce. You can blend in a little more oil if you want a looser drizzle.

Choose equipment made from stainless steel, glass, or food-grade plastic for contact with the wet basil and oil. Avoid reactive aluminum or copper. The oil does not need to be warmed: extra-virgin olive oil’s smoke point varies by product and refinement, and heat is not part of this recipe.

Wash and dry the basil

Rinse the basil under clean running water to remove dirt, then remove tough stems. Dry the leaves thoroughly with a clean towel or salad spinner. Water left on the leaves can dilute the mixture and reduce its quality.

For a brighter green color, blanch the leaves: dip them in boiling water for 10 seconds, then transfer them straight to an ice bath. Drain and dry them very well before blending. Blanching is optional, and it does not make the finished oil safe to store at room temperature.

Next step: Set out clean equipment before you begin, and decide whether you want to blanch the basil. Either way, dry the leaves well.

Blending and Finishing Technique

Blend the prepared basil with unheated olive oil until the leaves break down and the mixture looks smooth. Strain it through a fine sieve if you want a clearer oil, or leave it unstrained for a thicker sauce. Add salt when serving, not as a way to preserve the mixture.

Simple method

1. Prepare the leaves. Wash and remove tough stems. If you are blanching, dip the leaves in boiling water for 10 seconds, chill them in ice water, and dry them thoroughly.
2. Measure the ingredients. Add 1 packed cup of basil leaves and ½ cup of olive oil to a clean blender.
3. Blend. Blend until the leaves are finely broken down and the oil has an even, green appearance. Stop and scrape down the sides with a clean utensil if leaves cling above the mixture.
4. Adjust the texture. For a thinner drizzle, blend in a little more oil. Add it gradually so you can stop when the consistency suits your dish.
5. Strain if desired. Pour through a fine sieve into a clean container. Straining removes leaf pieces, but it is optional and does not extend safe storage.
6. Serve or chill. Serve promptly, or transfer to a clean, dry, covered container and refrigerate immediately.

A blender turns the leaves into a smooth sauce; a sieve separates some of the leaf material from the oil. Neither step is a preservation method. Add salt at the table or just before serving so you can season to taste.

Next step: Use clean utensils when transferring or serving the oil, and move any portion you are saving to the refrigerator promptly.

Refrigerated Storage, Freezing & Cleanup

Fresh-basil oil is a moist, low-oxygen food mixture. Keep it at or below 4°C / 40°F, refrigerate it promptly, and use it within 4 days. Do not keep homemade fresh-herb oil at room temperature, even if it looks or smells normal.

Why room-temperature storage is unsafe

Fresh herbs can introduce moisture and may carry bacterial spores. When herbs sit in oil, the oil creates a low-oxygen environment. Some bacteria, including the bacteria that cause botulism, can grow under low-oxygen conditions if other conditions allow.

A clean-looking jar does not show whether the oil is safe. Blanching, refrigeration, and added salt do not turn this fresh mixture into a shelf-stable product. Keep it chilled and follow the short storage limit.

How to store or freeze it

• Refrigerate the oil promptly in a clean, dry, covered container at 4°C / 40°F or below.
• Use refrigerated oil within 4 days. Discard any remaining oil after that.
• If you want to keep it longer, freeze it promptly in small portions. Take out only what you plan to use.
• Do not leave it on the counter to thaw or store it there between uses.

Freezing is a way to keep portions for longer than the refrigerated limit, but it does not make the oil suitable for room-temperature storage. No specific freezer duration is given here, so label portions with the date and use them while their quality is good.

Clean up safely

Refrigerate leftovers within 2 hours of preparation, and sooner when possible. In practice, the safest, simplest routine is to transfer the oil to the refrigerator as soon as you finish blending and serving.

Wash the blender, utensils, sieve, and storage container with hot, soapy water after use. Do not reuse a dirty or wet container for the next batch. Moisture and food residue can affect the quality of a fresh sauce.

Key takeaway: Refrigerate promptly, keep the temperature at or below 4°C / 40°F, and discard after 4 days. Freeze promptly if you need to keep portions longer.

Serving Ideas and Dining Presentation

Basil oil works best as a finishing sauce: spoon it onto food just before serving to keep its fresh herb flavor noticeable. Start with a small amount, then add more to taste. Keep the container chilled while you prepare the meal, and return unused oil to the refrigerator promptly.

Try it on:

• Roasted or steamed vegetables
• Cooked fish
• Pasta
• Bread served at the table

For a simple presentation, drizzle a little over the finished dish rather than mixing it into a hot pan. This keeps the recipe’s fresh, unheated character and helps you control the amount. Season the food or the portion of oil you are about to serve with salt; do not rely on salt to preserve the remaining batch.

In my cooking classes, a common point of confusion is whether a greener oil is also a safer one. It is not. Blanching can help preserve a bright color, but the same storage rules apply whether the basil was blanched or blended raw. Color and texture are serving choices; refrigeration and the four-day limit are safety steps.

Next step: Plate only the amount you need, then put the covered container back in the refrigerator.

Frequently Asked Questions

These answers cover the key choices in making, serving, and storing fresh basil oil. The main points are simple: use clean equipment, keep the oil unheated, refrigerate it promptly, and do not treat blanching or salt as preservation. When in doubt, follow the stated cold-storage limit.

Can I use raw basil?
Yes. Wash the basil, remove tough stems, and dry the leaves thoroughly before blending.

Do I have to blanch the basil?
No. Blanching for 10 seconds and chilling in ice water is optional and helps preserve a brighter green color.

Does blanching make the oil shelf-stable?
No. Blanching does not make fresh-basil oil safe to store at room temperature.

Should I heat the olive oil?
No. Use unheated olive oil for this recipe.

How much oil should I use?
Start with ½ cup olive oil for 1 packed cup of basil leaves. Blend in a little more if you want a thinner sauce.

How long does basil oil last in the refrigerator?
Use it within 4 days, keeping it at or below 4°C / 40°F. Refrigerate it promptly.

Can I leave the oil on the counter during a meal?
Do not store it at room temperature. Serve a small portion and return the covered container to the refrigerator promptly.

Can I freeze basil oil?
Yes. Freeze it promptly in small portions if you need to keep it longer than the refrigerated limit.

Can I add salt before blending?
You can season the portion you are about to serve, but salt does not preserve the oil. Add it when serving.

Can I use a wet jar?
No. Transfer the oil to a clean, dry container, then cover and refrigerate it promptly.

(This article was written by one of our staff writers, Daniel M. Whitaker. Visit our Meet the Team page.)