How can I prevent bacon mayonnaise from splitting when above fridge temp? I know how to fix a split mayonnaise made with olive or vegetable oil - that's not a problem.

I have made Kenji Lopez-Alt's recipe for animal fat mayonnaise (bacon fat, for putting on a burger). It emulsified beautifully, chilled wonderfully.. and then as soon as you put it on a burger it gets too warm and splits faster than a gymnast at the Olympics.

The recipe I used:


2 egg yolks
1.5tbsp Dijon
1tbsp white wine vinegar
salt and pepper
600mL bacon fat
800mL vegetable oil


Two egg yolks should be more than enough to emulsify this, and indeed were -- I had to add tons of vegetable oil just to get the right consistency. But as soon as the bacon mayonnaise gets above fridge temp, it splits immediately. It re-emulsified with agitation, but that's a bit tough to do when one is trying to serve a burger in a restaurant. Help?
I think the problem is actually not the heating, but the refrigeration!  

Consider: bacon fat solidifies easily and thickly, and does so even at room temperature. When you throw it in the fridge, the micro-droplets of bacon fat will turn to solids and clump together. These solid droplets are frozen in place when solid, but when you thaw it, they melt and reveal how wrecked your emulsion is.  Now, you could add additional emulsifying agents (lecithin, extra yolks) but that's not really going to solve the problem of refrigeration.

The solution is to break up the bacon fat as it melts, and re-establish the emulsion before it can break.  To do this, you have to whisk constantly as you gently heat the mayonnaise, generally in a warm water bath. 

How to execute this in a restaurant setting:

Prep a big batch of bacon-mayo and throw it in the fridge. Just before service, warm some water in a pot and throw a cup of the mayo in a small bain marie or metal 6th hotel pan.  Immerse the bain/pan in the pot, and whisk it as it melts.  Hold the mayonnaise for service in water warm enough to melt bacon fat, and DISCARD THE WARM MAYONNAISE EVERY TWO HOURS AND THAW A FRESH BATCH.  Make sure no cooks get lazy about that -- it's a food safety problem.  Ideally, you should be using pasteurized eggs to reduce the risk of salmonella. Basically, you're treating your mayonnaise like a Hollandaise or Bearnaise.  

I've found that the thawing trick works fairly well for home hollandaise (which most people say shouldn't refrigerate), and which does the same thing if heated fast.  It should apply to easily-broken mayonnaise too.