This past month, after continually lamenting the price of good dijon mustard and the lack of mayonnaise not containing canola or soy oil available at the grocery store, I decided to embark on a homemade condiment making journey! I started with mayonnaise and was shocked at how easy, inexpensive, and delicious it could be.  Homemade mayonnaise has a velvety texture and a more subtle taste.  In fact, it doesn't remind me at all of the Hellmanns mayo I thought tasted so disgusting as a child.  Below is the recipe I use for making mayo by hand.  This may sound laborious but it really doesn't take longer than 5-10 minutes.  I've also included instructions for making it with a blender or a food processor (neither of which I own).  And yes, this recipe does include a raw egg yolk.  I buy local free range eggs and feel confident about the health and quality of them.  The risk of salmonella lies mainly in conventional eggs coming from crowded feed lot chickens being fed antibiotics.  Before you use your egg, you can always do the fresh egg test by putting the egg in a bowl of water.  If it sinks, it's still good to eat.  If it floats, discard it. 
  

Basic Mayonnaise
Makes about 1 cup
1 large egg yolk at room temperature
*(if egg has been refrigerated, cover it w/ warm water and let sit for 5 minutes)
1 tsp Dijon mustard
2-3 tsp fresh lemon juice
3/4 c sunflower or olive oil
sea salt
-Recipe from Deborah Madison
 

1) Place egg yolk in bowl (1 qt should be big enough) and whisk it vigorously until thick and sticky.  I use a fork and this works fine.  Generally 1-2 minutes is plenty.
2) Stir in the mustard, a pinch of salt, and the lemon juice.
3) Whisk in the oil very slowly in a thin stream until the egg and oil have begun to thicken (when 1/3-1/2 of oil has been added).  Continue to whisk in the remaining oil in a thin, steady stream.  *Season to taste with additional salt, spices, etc.  I've been adding turmeric to mine lately or making an garlic aioli mayo by pounding 4-6 cloves of garlic into a paste with my mortar and pestle and adding this to the finished mayo.  
4) That's it! Your mayo is now ready to eat.  If it seems to thick, you can whisk in a little more lemon juice or water as needed. Cover and refrigerate until ready to use.  This mayonnaise should last up to 2 weeks in the refrigerator.  

In a blender: Put a whole egg, the mustard, and a pinch of salt in the blender with 1/4 c of oil and turn it on.  Add the remaining oil in a steady stream until all is incorporated, then add the lemon juice.
In a food processor: Use a whole egg plus another yolk. Plan to use an additional 1/2 c of oil and adjust the other ingredients accordingly to taste.  Start with eggs, mustard, and salt.  With the machine running, add the oil in a steady stream until all is incorporated.  Add the lemon juice.