"Egg (sometimes enriched) matzah" are matzot usually made with fruit juice, often grape juice or apple juice, instead of water, but not necessarily with eggs themselves. There is a custom among some Ashkenazi Jews not to eat them during Passover, except for the elderly, infirm, or children, who cannot digest plain matzah; these matzot are considered to be kosher for Passover if prepared otherwise properly. The issue of whether egg matzah is allowed for Passover comes down to whether there is a difference between the various liquids that can be used. Water facilitates a fermentation of grain flour specifically into what is defined as chametz, but the question is whether fruit juice, eggs, honey, oil or milk are also deemed to do so within the strict definitions of Jewish laws regarding chametz.
