Using a homemade herb oil adds a great finishing touch to your dishes. Herb oils are also nice in vinaigrettes for a hint of freshness. There are many ways to infuse oil depending on the ingredient being used. This technique focuses on the use of delicate herbs such as basil and mint.
The beginning steps describe a widely used method for creating herb oils. However using an Aeropress in the last step speeds up the finishing time drastically and gives a better yield than the traditional passive method of letting the oil drip through a fine filter with just gravity.
Avid coffee drinkers may know of the Aeropress. The Aeropress is a single serving coffee maker that is a cross between a french press and a Vietnamese coffee maker. Coffee ground and water are combined in the chamber and an airtight plunger is used to push the liquid through a paper filter directly into a cup. The Aeropress is highly regarded for the quality of coffee it produces at a very affordable price.
The more hardcore coffee drinkers will even recognize that I am using the inverted method for filling the Aeropress. I didn’t have time to take many pictures so those needing a visual reference can simply Google “Inverted Method Aeropres” for general tutorial.
Just a few things before we get started:
– I used a 1:2 herb to oil ratio. You can change this but in general, I feel this ratio strikes a good balance between yield and taste.
– I used basil as my herb but you can use any leafy herb. Mint, cilantro, even arugula works great.
– The oil you choose is up to you. A neutral oil such as sunflower, vegetable or grapeseed will highlight the flavor of the herb, but some people love to use olive oil and that’s fine too.
– Why blanch? SCIENCE TIME! Enzymes naturally present in the leaves will start to decompose the plant over time and turn the leaves brown. Blanching kills the enzyme and increases the shelf life of the oil. However, blanching does leech some flavor from the herb and heating the herb for too long will make it taste like wet grass. On the other hand, not blanching the herb will lead to color and flavor degradation over time. If you’re using the oil right away, skipping the blanch step may be a viable option.
Fresh Herb Oil – yields about 1 cup
2 qt water
1 tbsp kosher salt
100g fresh leafy herb
– Add water and salt to a pot and bring to a rolling boil
– Have a colander in the sink ready to strain the water and set up a bowl of ice water so the herb can quickly be cooled
– Please herbs into boiling water for 10-15 seconds, making sure that all leaves are submerged
– Quickly strain out the herbs by pouring it through the colander. Cool immediately in ice bath
– Remove the herb from the ice bath and squeeze as much water out of it as possible. One way is to ball up the herb and place into a paper towel to squeeze. When you think you’ve squeezed all the water out, replace paper towel and squeeze some more
– Place herb and oil into a blender and blend. Do not blend too long as heat generated from blending will compromise the color
– Set up the Aeropress for the inverted method. To do this, insert the plunger about half an inch into the chamber of the Aeropress so when turned upside-down the Aeropress can hold liquid in the chamber without leaking
– Pour the blend of oil and herb into the chamber and screw on the filter with a clean paper filter insert
– Before reverting the unit, push the chamber down into the plunger until there is no more air in the chamber
– Revert the Aeropress onto a sturdy vessel and press slowly until all the oil is extracted. Because you are pushing oil through pulp in a device intended for water and ground, there will be some resistance. Be patient and make sure the vessel the oil is going into can handle the pressure you are putting on it. Push too hard and the herb may push through the filter
Preparing an infused herb oil is typically a full day process with a lot of waiting involved. One misstep could mean you don’t have enough oil for service. Gravitational forces can only extract the oil out so far so fast. Having containers of dripping oil in the walk-in with strainers and coffee filters precariously balancing on top are not only space hogs but a spill waiting to happen.
This method requires more active time to prepare but drastically cuts down the whole recipe time. There is also a greater yield when mechanically pressing the oil through the filter.