<snip>One gram is, in fact, a very tiny amount and I suspect that it
would be of no consequence....
One other thing, a gram is very hard thing to visualize. How much is
a gram? A teaspon or a tablespoon, on the other hand, is something
for which we all have a working knowlege.<snip>
Everyone finds a system for measuring items that works best for
them. Dave is comfortable with volume based measurements. I on the
other hand, get much more consistent results when I use weight (or
mass) based measurements. It is well documented that the weight of
one cup of flour will vary from person to person to person (and can
vary by cup to cup for the same person). These variation can range
from 1/4 oz to 1/2 oz. When measuring 4 cups of flour the error can
be as much as 1 cup or 25% from the stated recipe. This is because
of how the flour is put in the measuring cup - i.e., how you scoop up
the flour, how much force one uses. Think of flour as brown sugar
and consider the difference between a packed and an unpacked unit
(tbp, cup, etc.) - the weight of brown sugar in an unpacked vs a
packed unit will vary with the amount of force used to fill it.
Dave is not thinking of a gram with the right frame of mind - it is a
mass based unit and should not be thought of in terms of volume. As
a massed based unit you cannot visualize an equivalent volume unless
you know the density of the material you are measuring. The best
analogy I can think of, is everyone knows how much they weight but
nobody knows how much volume they take up! A cup is a volume based
measurement and a gram is a weight based measurement.
A gram of feathers or air takes up a lot more volume than a gram of
lead, just as a gram of yeast takes up a lot more volume than does a
gram of water. If you really want to visualize a gram you must know
the density of the material. Water for example has a density of 1
g/cm3, therefore 1 gram of water takes up the volume of one cubic
centimeter. Flour and instant yeast have densities less than water
so 1 gram of each has a volume greater than 1 cubic centimeter. For
comparison the volume of a cube 1 inch by 1 inch by 1 inch is about
equal to the volume or a cube 2.5 cm by 2.5 cm by 2.5 cm.
By measuring all your ingredients by weight you will avoid the errors
and inconsistencies that are inherent in volume based measurements of
dry ingredients.
Another member wrote: <snip>The only warning is to avoid direct
contact between salt and yeast as it will kill the yeast.<snip>
This advice is not really accurate. You can safely measure all your
dry ingredients together. If salt and instant yeast make contact,
salt will not kill the yeast. The yeast cells are dormant in this
freeze dried state, for salt to kill a cell like yeast the yeast must
be in an active state (i.e. hydrated) and the salt concentration must
be much, much higher than in bread recipes. Obviously the salt in
dough does not kill yeast or your bread would never rise. What
happens when you are making dough is that once you add the liquid
ingredients the salt eventually dissolves in the "wet" hydrated
flour. It is questionable whether the small amount of salt in bread
has any measurable effect on the yeast cells. Some book authors out
there claim that the salt regulates yeast, which is true in
laboratory settings - however, all the documentation I have seen, the
salt concentrations are much higher than that found in bread
recipes. There is also some data to suggest that salt contributes in
a very small way and by some unclear mechanism to the crumb structure
of bread. However, the main function of salt is as a flavor enhancer
- it makes things taste better.
Tom