All about coffee by William H. Ukers

2 by William H. Ukers, Ukers, William H. (William Harrison), 1873-1945

Chapter 80: 8. _Ash Insoluble in Acid--Official_

Chapters

Chapter 80: 8. _Ash Insoluble in Acid--Official_

Boil the water-insoluble residue, obtained as directed under 9, or the total ash obtained as directed under 7, with 25 cc. of 10-percent hydrochloric acid (sp. gr. 1.050) for 5 minutes, collect the insoluble matter on a Gooch crucible or an ashless filter, wash with hot water, ignite and weigh.
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