Both liquid malt extract and dried malt extract are made from wort (unfermented beer), which is made from mashing grains. Liquid malt extract is made by evaporating the water at low pressure and fairly low temperature until it is a thick syrup. (Brewery grade) dried malt extract is made by spraying droplets of condensed wort into a tower under a vacuum. As the droplets fall, they shed moisture and fall to the bottom as a powder.
Dried malt extract (DME) is a more dense than liquid malt extract (LME) because more water has been removed from it. If you dissolve 1 pound of dried malt extract in a gallon of water, the specific gravity would be near 1.045. If you dissolve 1 pound of liquid malt extract in a gallon of water, the specific gravity would be in the range of 1.0331.038.
Because it contains less water, dried malt extract keeps longer (as long ad you keep it sealed away from any moisture, even the moisture from air). However, because less water has been removed from it, wort made from liquid malt extract is lighter in color.
Chris Colby
Editor
beerandwinejournal.com