Place the garlic, salt, and lemon juice in a tall, narrow container, then pour the oil on top.
Insert the hand blender all the way to the bottom and turn it on. Keep it completely still for 2–3 minutes, until the bottom layer thickens and begins to emulsify.
Slowly lift the blender about an inch, lower it back down, and repeat. Continue this gentle up-and-down motion—one inch at a time—until the entire mixture emulsifies and becomes light, fluffy, and smooth (about 6–7 minutes total).
Transfer to a sealed container and refrigerate for up to one month.
