This article is from the Food Preserving FAQ, by Eric Decker firstname.lastname@example.org with numerous contributions by others.
Unless specified otherwise, sugar is granulated sugar. Dissolves easily,
easy to pour and measure, and all the recipes are calibrated to its volume
email@example.com (Prograf) writes:
what are the precautions I should take when storing white sugar for long
periods of time? Is there a way to keep it from getting hard? I've
checked the FAQ but couldn't find any information about it. [ thank you
for your question. The info is NOW in the FAQ - ED]
For longggggg term storage of sugar you can use honey rather than refined
sugar. Honey needs to be stored in food grade poly pails. Guard against
water penetration. If you wish to keep white sugar from lumping you will
need to keep it absolutely and perfectly sealed from moisture. Use poly
food pails and seal well to keep moisture out. Sugar has an immense
affinity for a water molecule.
If you wish the flavour of refined white sugar there is another way.
Make a 50% solution of sugar ( use filtered or distilled water ) and
bottle it off. Yeah I know it is sugar but if you want to preserve it
for a long time you will need a vacuum. Oxidized sugar solution is
yucky. You should Pressure Can it to exhaust the jar. 50% sugar
solution doesn't need pressure but by using a pressure canner you can
get the high vacuum that BWB cannot produce. For shorter term storage
you can store 50% sugar solution in gallon bottles of the type used for
laboratory reagents. Typically the glass is dark brown [ mandatory imho]
and the stopper has a plastic seal [ highly recommended ] not cardboard.
Using a funnel, fill right up to the narrow neck. Leave at least 1 inch
for expansion. Make sure there is no sugar solution around the rim - wipe
it with a clean damp cloth to be sure. The stoppers are equally clean and
used straight from a pot of lukewarm water. Apply the stopper tight. Store
in a cool, dry dark place.
How to get a 50% solution?
Weight of sugar and water to make one gallon.
To make a 50% solution put 1,892 grams of sugar into a pot with 3,785 grams
To make a 50% solution put 2,272 grams of sugar in a pot with 4,545 grams
It will be more than one gallon but by working this way you get the
correct solution. You WILL need to heat the solution to get that much
sugar to dissolve. Do not overheat or you will scorch the sugar and
induce a bad taste which will magnify with time in storage.
The idea behind making a defined solution is you know exactly its strength
which will allow using it in nearly any recipe.