[Sca-cooks] Egg tempera query

[Phil Troy/ G. Tacitus Adamantius]

Also sprach Avraham haRofeh of Sudentur:
>  > >I'm assuming there is some added water content, but has anyone here
>frozen
>>  >egg yolks and then defrosted them and used them for tempera painting? Is
>>  >that a Yay or Nay on the Feasibility Front?
>>
>>  I have a half gallon of eggs whites in my freezer (less what I have used)
>>  and it works fine for me whatever I use it for.
>
>Egg whites freeze beautifully - egg yolks don't. The emulsifiers in the yolk
>are substantially (up to 50%) less effective after freezing.
>
>Avraham

This is interesting; either different rules apply or it's an example
of he difference between theory and practice. Harold McGee actually
recommends, in "The Curious Cook", that smaller quantities of frozen
and thawed egg yolk (specifically because they are thicker) be used
for things like mayonnaise, to reduce the risk of salmonella and that
sort of nastiness. I suspect that the result is less stable than
ordinary mayo, because it relies more on the thickness of the yolks
(similar to the way mustard is used to help emulsify some
vinaigrettes) than on the emulsifier/detergent (this last being a
chemistry term; look it up) qualities of the yolks. I guess it does
come under the heading of "different rules".

Adamantius