We do not eat mayonnaise very often and I just cannot bring myself to buy the store brands. The 'health food store brands' are high quality ... with a price to match! While I do not go so far as to using grapeseed oil, I am at least content to know it is as fresh as possible with real ingredients that are usually on hand.
Total time is about 10 minutes from start to finish, including clean up. You will only need FIVE things: 1c oil of your choice (of course the different oils may change the flavor of the end product), 1 egg, 1 1/2T vinegar (or lemon juice if you prefer), 1/2t salt, & 1/2t mustard powder. I use a blender, however an electric mixer will work too.
Place everything EXCEPT the oil into the blender. Blend on low speed till mixed (a few seconds). Add the oil while the blender is on low (if you have a Vitamix, I set mine on variable speed 4) - the oil should be a slow, steady stream like this:
Here's a look from the inside just starting:
Below is a shot after about 20 seconds - the mixture will start to look more and more like mayo (mine looks more yellow here than it actually is .. the lighting was bad!). If you add the oil too fast, it will not blend properly ... so make sure to go slow! Soon it will get very thick; you may need to stop the blender to scrape down the sides.
Once all of your oil is gone, it should be done. Does it look like mayo? Does it taste like mayo? I've found that I like a little extra salt and vinegar in mine, however start with what I posted above, and adjust from there. Take notes and put your final adjusted recipe into your recipe box, book, or whatever.
This will make a little more than one cup of mayo; store in the refrigerator for up to about 2 weeks.
If you make it, let me know how it goes!
I am going to try to make an egg-free kind soon. I'll post that if and when it turns out.