Originally Posted by Tina At Sugar Wishes:
Can I ask a really stupid question?
Why not use fresh egg whites?
Hi Tina (and everyone 
). As the engineers we are, and after a lot of experimentation, we have reached to the following conclusions: as we all know, royal icing is basically a mixture of egg whites and sugar, and in order to prepare it, we can use the egg whites in one of these forms:
- Egg white obtained directly from a fresh egg. The albumin concentration in the egg white is lower than the one we can obtain with dried albumin, and for this reason, the icing will have an inferior quality.
- Pasteurized in a liquid form. The icing has a poor quality for the same reasons as in the previous point.
- Meringue powder. The main ingredient here is dried egg whites, that is, albumin, and depending on the manufacturer, additives vary: stabilizers, anti solidifiers such as starch, aromas, cream of tartar and white colouring. It does not have any water so, when we use it, we can increase the proportion of gram proteins in the water, which will allow the icing to have much better quality than in the two previous points. Wilton or Lorann Oil are brands with manufacture MPowder.
- Using egg albumin. By dehydrating the egg whites we obtain the pure protein it is made of, also known as albumin.
We always use dehydrated egg albumin for our royal icing. There is a massive different in the result and with the right proportion there is no problem with taste or smell.
Hope this was helpful for you and have a great weekend!