Generally, even the mayonnaise varieties that claim on the front label to be "made with olive oil" are actually made with a blend of oils that includes olive oil but is primarily comprised of other oils (e.g., soy or canola) which are not mentioned on the front label. With the recipe included here, you will know with absolute certainty which ingredients you are consuming, and you will be using ingredients that actually contribute to your health such as, raw unfiltered apple cider vinegar, raw honey, and flax seed.
The first key to foolproof mayonnaise is to use a stick blender (or immersion blender) and the accompanying mixing cup. If you are accustomed to making mayo in a regular upright blender, then you will appreciate that the stick blender method does not wear out your arm by requiring you to drizzle oil into the mayo in a slow, steady stream. The other key to fool-proof mayo is to use a recipe like this one that is based on a mixture of flax meal and water, rather than eggs.
This mayo will likely have a slightly green hue from the grapeseed oil, and specks of flax meal will also be visible in the finished product.
Grapeseed oil adds a fairly neutral flavor to mayonnaise. If you substitute extra virgin olive oil or any other stronger tasting oil, you may wish to increase the amount of honey.