A term coined by the forest-products industry to describe an abusive subsidy scheme within the industry. Black liquor is a byproduct of creating wood pulp and is used as fuel. As part of the 2005 transportation and ethanol bill, the U.S. government created a tax credit designed to encourage companies to use biofuels by mixing them with fossil fuels (presumed to be their existing energy source). An extension of the bill in 2007 created a loophole whereby paper companies, who were already using a biofuel (black liquor) did the reverse of what the bill intended, adding diesel to their black liquor, to qualify for tax credits.

The paper companies' use of a biofuel/fossil fuel mixture then qualified them for the tax credit, violating the spirit of the bill but not violating the law and allowing them to claim several billion dollars in tax credits. The tax credit distorted global markets by reducing the price of some U.S. paper products and caused Canada to create a similar subsidy to remain competitive with U.S. forest-products companies. The tax credit was scheduled to expire at the end of 2009.