Malt extract, in particular liquid malt extract or LME, is known to create a darker finished beer because it is a concentrated product created with heat and low water content. It allows for the brewer to skip the time- and attention- intensive processes of mashing and sparging, since these processes are completed to create extract. A wort is made through mashing and sparging, then concentrated down to a thick syrup (for LME, powder for DME) by boiling off most of the water.
Many malt makers boil the wort under vacuum pressure to keep the boiling point of the water low, but the time, heat and reduced water content will darken the melanoidins, or primary coloring agents, in the wort. Therefore, even malt extract made with very light-colored malts will be darker than a comparable all-grain wort made from the same malt. This can cause a challenge when brewing very pale beers such as Kölsch with malt extract.
1. Do Not Caramelize Partially-Dissolved Malt Extract
As you pour liquid malt extract into hot water, it does not dissolve evenly or instantly. It instead needs to be stirred to combine with the water because it is thick like molasses. Small, caramelly blobs of extract can remain, even after attentive stirring. If the bottom of the pot your cooking in is hot, those small blobs can caramelize onto the bottom of the pot. Scorching extract onto the bottom of the pot is sure to darken the wort.
To avoid darkening your extract brew, be sure to turn off the heat before stirring extract into the water. You will want to stir until you no longer see small partially-dissolved blobs of extract in your wort, then continue to stir for about a minute for good measure.
2. Do a Partial Mash or Steep using DME
Dry malt extract undergoes similar processes to liquid malt extract, however even more water is removed, allowing it to stay fresher and store longer. Brewing with dry malt extract also provides a lighter finished beer than brewing with liquid malt extract. Many brewers choose to start with a very light-colored dry malt extract then mash or steep specialty grains until the proper color is achieved.
3. Be Sure Your Extract is Fresh
Fresh and properly-stored liquid malt extract is crucial for achieving a lighter finished beer. The older liquid malt extract gets, and the more it is exposed to heat/warmth, the darker the melanoidins in the extract become. If you want to be confident that your beer will stay on the lighter end of the spectrum, you’ll want to be sure the Best By date on your extract is far off and you are storing it in proper conditions.
Though even with all of these smart tips at your disposal, it’s important to remember that lightening your beer will not make it any more flavorful or refreshing. It’s a greater priority to choose the right extract for the style of beer you wish to brew, than for the color you believe it should have.