This recipe uses an immersion blender. You need to use a cup or glass that is only slightly bigger than the immersion blender. If your blender came with a blending cup, that's a great one to use. Otherwise, consider a canning jar that is just slightly bigger. Using a large bowl or larger cup will not work.
Place all ingredients in a tall jar or cup that fits your immersion blender.
Place the blender at the bottom of the jar and blend on high without moving the blender. Once you see mayo start to form, you can move the blender slowly upwards until all the mayo is blended. Do not over blend. This will take less than 20 seconds.
Store in refrigerator immediately and up to 1 week.
Storage Notes: There are varying opinions on the shelf-life of homemade mayonnaise. Some people won't keep their mayo longer than three days no matter what, while others say it expires when the date on the egg carton says so. I have found that a week is just about right. You'll notice a slight change in flavor, consistency and sometimes even color when it starts to turn. But above all, please keep it in the fridge at all times! There are also plenty of folks out there that do not use pasteurized eggs. That is your prerogative. With a little one at home, I tend to err on the side of caution and use the pasteurized eggs for this.
Please note that the nutrition data below is a ballpark figure. Exact data is not possible.