在使用树脂木材的碱性制浆过程中，木材中的松香和脂肪酸被皂化并溶解在废蒸煮或消化液中。由于黑液通过蒸发浓缩，一些有机酸皂和一些不皂化物质变得不溶，可能会从黑液表面撇去。如今，许多碱性纸浆厂都有酸化装置，用于将这些塔尔油撇渣转化为原油塔尔油；因此，许多工厂向化学品制造商推销这种产品。 塔尔撇油的分析方法见TAPPI T 635《塔尔撇油的分析》本程序仅适用于原油“酸化”塔尔油的分析。酸化过程中的操作变量会以各种方式影响油的质量； 因此，生产商和消费者都使用这些分析测试来监控原油的质量。

In the alkaline pulping processes using resinous woods, the rosin and fatty acids in the wood are saponified and dissolved in the spent cooking or digestion liquor. As the black liquor is concentrated by evaporation, some of the organic acid soaps plus some unsaponifiable material become insoluble and may be skimmed from the surface of the liquor. Many alkaline pulp mills today have acidulation plants for converting these tall oil skimmings to crude tall oil; therefore, many mills market this product to chemical manufacturers. The methods for analysis of the tall oil skimmings are contained in TAPPI T 635 “Analysis of Tall Oil Skimmings.” This procedure pertains to analysis of the crude “acidified” tall oil only. Operating variables in the acidulation process can affect the quality of the oil in various ways; therefore, these analytical tests are used by the producers as well as the consumers of crude tall oil to monitor its quality.