What is malt extract?

Malt extract is basically an unrefined sugar derived from malted barley. It is the primary source of fermentable sugars in homebrew. The more you add, the greater the alcohol content, body and flavor of your beer.

What is the difference between "Gold/Light" malt, "Amber" malt and "Dark" malt?

For the most part, malt extract manufacturers will not disclose the mash ingredients of their extracts. "Gold", "Light" and "Pale" are three names for the same thing. These malt extracts are primarily made from Pale Malted Barley, such as American 2-Row (if it is an American extract), or British Pale Malt (if it is British). Light malt extract is the lightest, and most neutral extract you can buy.

"Amber" malt extract is darker and sweeter than "Gold/Light/Pale" extract. Like light malt, it is normally made from a base of Pale Malt, and may be darkened with caramel malts, Vienna malt, or Munich malt.

"Dark" malt extract is normally the darkest malt extract you can buy. It leaves behind more residual sugar than Light or Amber malt. Dark malt is normally made from a base of Pale or Munich malt, and darkened with caramel malt or a very small amount of black malt. It does NOT contain a substantial amount of roasted grains, such as chocolate malt or roasted barley. If you are making a porter or a stout, you would often be better off working with light malt extract, and steeping chocolate malt and/or roasted barley.

What is the difference between malt extract syrup and dry malt extract (DME)? What is the ratio of DME to malt extract syrup?

DME is malt extract that is almost completely dehydrated, whereas malt extract syrup still contains some water. Because of the additional processing, DME is normally more expensive than malt extract syrup.

A good rule of thumb is that dry extract is 1.2 times as concentrated as syrup. Syrup is 0.8 times the concentrate of dry. For example, 1 pound of dry extract would equal 1.2 pounds of syrup, and 1 pound of syrup would equal .8 pound of dry extract.