SC - Juice of sour oranges--source

[Aelfwyn at aol.com]

In a message dated 3/27/00 4:55:48 PM Pacific Standard Time, Lady Brighid ni 
Chiarain writes:

<< note: orange juice would refer to the juice of sour oranges.  In _The 
 Medieval Kitchen_, it is suggested that one can substitute the juice of 
 two oranges mixed with the juice of a lemon. >>

I am doing the orange chicken recipe from _Medieval Kitchen_ this Saturday 
for feast. Much to my amazement Shop and Save (our Maine grocery chain) had 
juice of sour oranges in the international isle. It is a Goya product so 
probably widely available. Who'd a thunk it?
Aelfwyn