Hand Matzos always seem to be round, yet machine Matzohs seem to be square. Is there any company anywhere that produces round machine Matzos? Why not?
Rakusen's of England makes cracker-sized machine "tea matzas", and they're round! (Mind you, you'd have to eat a few of those "crackers" to have a complete serving of matza for the mitzva.) The only ingredients are flour and water, so they truly are matzas. I've occasionally seen them in American supermarkets.
With the early machines in the late 1800s, they'd have a giant roller cranking out a huge flat sheet of dough, then use big cookie-cutters on it. If you used round cookie-cutters, you'd either have to throw away all the dough in between the circle shapes, or would feel pressured to rework it within the 18 minutes, which is going to be hard to do. Therefore they were advised in fact to make them rectangular-shaped.
Of course this raised eyebrows with some traditionalists: "gevalt! Everyone knows a matza is supposed to be round!" The Kesav Sofer (in a pamphlet known as Bitul Moda'a, printed in the back of his responsa on Orach Chaim) briefly allowed for machine round matzas (or even theoretically a pentagonal shape), to give time for people to adjust, while pleading with people to accept the rectangular matzahs, "and in this merit may Hashem gather us from the four corners of the world." (Groan.)
With today's technology I'm sure they could make them round, but as noted that makes packaging more complicated. And besides, if the rabbis of 100+ years ago said that machine matzas should be rectangular, then by golly we'll make them rectangular!
Furthermore, many people feel that the machine matzas can't be used for the seder (which is a different question.) If they started making round machine matzas (or handmade non-shmurah for that matter), people might eat sub-optimal matza seder night, or at least accuse the manufacturer of trying to cause such a confusing situation.
If such matzos are rare or nonexistent, it's because they don't fit as well in a box and thus require either
- a round box, which costs more to make and assemble, or
- more box space per matza, taking up valuable room in shipping etc., and
- empty space in each box, increasing the likelihood of breaking matzos.
Source (so to speak): conjecture.
1- It is more efficient to produce square matzah than other shapes. 2- Most probably, the matzah eaten by the Hebrews leaving Egypt, was square and not round, because the frames used to make bricks were either square or rectangular and so the tradition would probably be to take those same frames and transport the dough that way. 3- The suggestions that one may use the excess dough remaining after the cookie cutter device used to make round matzah would create "Gebroken" matzah, not used by many Jews on Passover.