There are some questions in life that can’t be answered simply, like whether we were created by some divine deity or whether the chicken or the egg came first, and then there are some that are equally curious but much simpler to answer.
The other morning on a journey through the kitchen I noticed how incredibly white the mayonnaise in the fridge was and started to ponder why it might be so… The fact is that when I make mayonnaise at home it is really yellow which makes sense because egg yolks are yellow, but when I buy it in a shop it is oh so very white.
What I needed to know is why isn’t the shop mayonnaise yellow, do they bleach it or something?
Obviously they don’t actually bleach mayonnaise, it would be a pretty extreme way of whitening and even ‘bleached flour’ isn’t actually bleached. With flour they add a ‘bleaching agent’ to oxidise the outside of each grain, but I digress…
What I discovered is that commercially produced mayonnaise is actually whiter than the stuff that you might make at home for a number of reasons, I have decided to call them the 3 W’s:
W1 – Water
You don’t add water when you make mayo at home but many commercial producers (like Hellman’s) do. Read the label on a jar of shop bought mayonnaise and it is very often the second ingredient listed by volume after the oil.
W2 – Whites
You almost certainly use only yolks but commercial mayonnaise often uses whole eggs in place of or in addition to yolks. Egg whites don’t emulsify as easily as yolks do, which is why you will often see Lecithin listed in ingredients – it is an emulsifying agent.
W3 – Whisking
The more air that you get into your mayo the whiter it appears due to the magic of oxidisation. Mayo produced in a factory uses massively powerful mixers that beat a lot more air into the mixture than your puny home blender/food processor/hand and whisk can manage.
There are a couple of other possible factors that I can’t make begin with a W. The yellowness of the final mayo can also be influenced by the type of oil that you use, some add more colour than others and where the eggs come from. Compare the colour of a yolk from an organic corn fed free range chicken and one from the cheapest supermarket egg and you will see what I mean.
Oh, and just for the record. I don’t believe in any deity and I’m fairly sure the egg came before the chicken.