"Victor Sack"
> Lass Chance_2 wrote:
>
>> Most "cramed" soups start with a roux.
>
> Not really. There are various ways to bind soups and sauces, and roux
> is by no means the default. I posted about this before. See, for
> example,
> <http://groups.google.com/group/rec.food.cooking/msg/dcc7ede9851ada04>.
>
> Clam chowder, which the OP had in mind, would not necessarily need any
> additional binding, since the starch in the potatoes contained in the
> soup may well provide enough of it. Whether any extra binding is needed
> might depend on whether one prefers the chowder to be more creamy or
> more chunky. Many traditional chowder recipes omit any extra binding.
>
> Victor

Both clam and fish chowders as made in Maine use the potatoes for
thickening. Once they are cooked, smushing some of them provides plenty of
starch. Both are also left to be eaten the next day, during which time they
thicken more from leached starches.
My mother would have fainted at the idea of putting flour into it or eating
it the day you cooked it.