SC - Yolks vs whites

[Philip W. Troy]

linneah at erols.com wrote:
> 
> Pardon my ignorance, as you all have many times before, but what does an egg
> yolk do (other than fat and taste) that egg white doesn't?  I'm trying to keep the
> fat content down as much as possible and was wondering if substituting would
> effect anything seriously.  I know that the taste will be different, but what
> else?
> 
> Thanks,
> Linneah

There are some dishes in which the substitution of egg whites for whole
eggs or yolks would make a big difference.

While the yolk contains virtually all of the fat of the egg, the white
contains most of the protein. Albumen in the white tends to curdle when
cooked, so it isn't as good for things like custards as yolks or whole
eggs would be. Also, without the fat, baked goods tend to be a bit
tougher. Conversely, egg yolks generally tenderize baked goods, since
they contribute some shortening fat.

I suspect the thing to do is to find some recipes that use egg whites,
so as eliminate at least some of the less effective experimentation. Off
the top of my head, I think I recall that there are various biscuit
recipes that call for egg whites (certainly things like the white bisket
bread found in Elinor Fettiplace, which is essentially meringue, and
quitperiod, no matter what you may have read). Ditto macaroons. Also the
cheesecake called sambucade in the Forme of Cury uses egg whites and a
curd cheese, which could easily be of the low-fat variety.

I'm sure there are several others, but would have to check into this a
bit deeper.

Happy hunting!

Adamantius