NPK Fertilizer corn steep liquor powder 42% (a.k.a. condensed fermented corn extractives) is a by-product of the corn wet milling process. According to the Corn Refiners Association, “CSL is a viscous liquid mixture consisting entirely of water-soluble components of corn steeped in water” .organic fertilizer corn steep liquor powder 42
Since the corn kernel is a complex mixture of starch, protein, oil, water, fiber, minerals and vitamins, the corn wet milling process yields many widely used products such as corn oil, corn germ meal, cornstarch and high fructose corn syrup. Corn is soaked, or “steeped” in 120°F to 130°F water containing 0.1%–0.2% sulfur dioxide for 24–48 hours. The sulfurous acid formed induces chemical and physical changes in the kernel, in effect separating the starch and insoluble protein by cleaving protein disulfide cross-links in the endosperm protein matrix. (Dailey, 2000.)corn steep liquor for agriculture
The sulfurous acid also helps to control undesirable microorganisms, and allows dissolved sugars to be converted to lactic acid, which helps to maintain a pH near 4.0. During the steeping process, about 6% of the dry weight is dissolved, which is then evaporated to condense the steepwater into corn steep liquor. (Corn Products International, 2009.) The remaining insoluble corn kernel is then further processed to produce many products used in foods, livestock feeds and fertilizers.100% Water Souble organic Fertizilizer corn steep liquor powder 42