<<Disclaimer: Verify this information before applying it to your situation.>>

Well, I learned a lot -- thanks all.

My original question was: I'm curious about the difference between potato
flour and potato starch.  I notice in Betty Hagman's bread book she uses
each of them in a different flour mix.  I'd like to know what the difference
is between the two and how they act differently in cooking and baking.  Our
local grocery store has "potato starch flour" in their natural foods
section.  I haven't bought it because I don't know if it would be ok to use
in place of either the potato starch or potato flour in recipes.  My first
thought was it's labeled that way because it's potato starch in a "flour"
form (i.e. powdered instead of granular???).


The responses I received follow:

Potato flour is much heavier than potato starch, and is rarely used and
if so, in very little quantity.  You cant interchange them.  Just follow
the recipes by the letter. Tapioca starch and tapioca flour is the same
though.  You can go to this other excellent site:
http://forums.delphiforums.com/celiac/messages/

*****

Potato flour is heavier than potato starch. ( I don't know why it is
sometimes referred to as potato flour starch.)  I use potato flour in
cookies, gravies, sauces - slightly less than I would use of wheat flour.
For breads & pie crusts I use the starch.  The nicest thing about potato
flour for cookies is that I don't use guar/xanthum gums. Most health food
stores seem to carry the starch.  The only place I have been able to find
the flour is thru Ener-G

*****

"potato starch flour" as found in the grocery store is "Potato Starch"
to Bette and most other recipes. Potato Starch is much finer and whiter,
much like cornstarch in texture. Potato Flour is much heavier and has a
more pronounce potato flavor.  That is why it is a smaller portion of
the blend in a recipe.   It is harder to find, but I get it online. The
two are NOT interchangeable. For the best use of the two, go to
www.astoriamagazine.com and get the Kaiser Roll recipe.  It's free.
Makes the best bagels and pizza I've made in two years.

*****

Any time I've seen something labeled "potato starch flour", it has
referred to potato starch.  The flour is denser and has a different
texture.  Once you've seen both they're easy to tell apart, but
difficult to describe.  They both have their uses, but I use potato
starch far more heavily than I use potato flour. You may also wish to
compare prices between the potato starch in the health food section, the
potato starch in the regular baking section or Jewish food section (not
all stores have it, period, but some will have it in both spots), and
the potato starch at an Asian market. The Asian markets which carry
Japanese goods will have potato starch (which means most of them, at
least in the US).  The potato starch in the health food section tends to
be the priciest, and the potato starch in the Jewish food section (if
they have it), tends to be the same price or cheaper than the Asian
markets (on potato starch only - the other starches are all cheaper at
the Asian markets). Your mileage may of course vary ;-)

*****

Potato flour is much more sticky like Sweet Rice flour. Potato Starch flour
is used in her first mixture of flours. Using Potato flour and not the
starch would produce a gummy sticky product.

*****

Potato flour is make from whole potatoes.  It has lots of fiber and will
hold as much water, like a sponge, that you want to add.  It hold moisture
in baked goods.  Potato starch & potato starch flour are the same
thing--just the starch.  It thicken to produce a gooey texture--I use it in
place of wheat flour to thicken my German potato salad. Potato starch flour
is also found in the kosker food section in grocery stores in areas where
there is a Jewish popolation. There is nothing really 'natural' about a
product which is pure starch, kind of like 'natural' corn starch.  Not like
whole grain or stone ground...just starch.  Below I'm including a recipe for
sponge cake that appears on the back of Manischewitz potato starch.  Like an
angel food cake with cholesterol.  {{Tami here -- if any one wants this
recipe please message me.}}

*****

Potato starch flour is the same as potato starch.  They are both real white,
with a consistency similar to corn starch. Potato flour, on the other hand,
is not as pure white, and is not as fine textured.  It more resembles the
looks of wheat flour in a container.  I personally, do not ever use potato
flour, but I use potato starch all the time in  my GF baking.  Also,
according to what I have read, the two are NOT interchangeable in recipes.

*****

Potatoe flour would sink the Titanic. Very few recipes use it. Potato starch
is wonderfully light and used in just about everything we eat.  I buy pounds
and pounds and pounds of this and of tapioca starch which makes wonderful
easy to roll pastry.

*****

they are truly very different products, and one does not substitute for the
other. Both of course come from potatoes, and so are quite safe for us
celiacs.

*****

Potato flour is the whole potato dried and ground; potato starch/potato
starch flour is the starch of the potato separated with water, dried and
collected.  Potato flour is heavy and is generally used in very small
portions.  Potato starch (flour) is used with rice flours, generally in
addition to tapioca starch (flour) to make a better baking mix.

*****

I buy both form ENER-G.  I use both.  I find both vastly different.  Starch
is more like cornstarch.  Flour is more like brown rice flour in consistency
but requires vast amounts of liquid. Starch readily mixes with liquid.
Flour takes a tremendous amount of liquid to achieve the same consistency.
I use the flour when I want the "heavy" and starch when I want a "regular".
If this is of any help to you. I have my own GF mix.  When I accidentally
used the flour, nothing was turning out.  Everything was way too heavy or
wouldn't rise, etc.  I tend to use some flour when I'm making bread because
I want the heaviness esp. in rye bread.

*****

Think of it as the difference between corn starch and corn flour.  One is
the whole food, the other has just the starch extracted from it.  Anything
labeled 'potato starch flour' will be the pure starch.  You can tell by
looking at it:  it will be this pure white extremely fine powder, like
cornstarch.  The potato flour is a much heavier powder that appears a bit
grayer than the starch and as a different texture.  Bob's Red Mill sells
both.  The potato flour will never have the word 'starch' added to its name.

*****

I can tell you that potato starch flour is potato starch.  I also know that
the two products are NOT interchangeable in recipes, but I can't tell you
why or what is different.