Post by Duncan BoothMcGee says "usually there's no difference, but beet sugar can sometimes
have a slight off flavour".
If the grain size is different then so will be the density. The recipes
in the article all follow the US practice of measuring by volume and
baking is one area of cooking that needs accurate measurements so it
wouldn't surprise me if that was indeed sufficient to explain most of
the difference they found.
I tend to agree. And possibly a certain variation in residual water. But
there will always be "impurities" - it's refined, but not pure sugar.
I'd like to see the "cooks that know" try a double-blind test and then see
what happens.
And as you say the US love of measuring everything in cups (for sugar,
flour, butter etc) would - I expect - lead to more of a variation than
anything in the sugar.
Grain size has nothing to do with the source of the sugar though. It's
purely down the processing in the factories (the market and cultural
differences). Granule size can vary from country to country.
There is basically one grade of "granulated" sugar in the UK, whereas there
are two grades available in Austria (one coarser and one finer than the
UK), and the icing (powder) sugar in the UK is finer than the icing sugar
here.
--
Tim C. Linz, Austria.