Definition of "acidulate"

acidulate

/əˈsɪd͡ʒʊ.leɪt/

verb
third-person singular simple present acidulates, present participle acidulating, simple past and past participle acidulated
1. (transitive) To make slightly or moderately acid; to acidify.
2. (transitive) To make sour in a moderate degree; to sour somewhat.
  Quotations
  Twenty leeches were ordered to be applied round the nose every two days; frequent emollient fomentations; the local vapour bath; general bathing; stimulating pedilavia; a strict regimen; vegetables, milk, white meats; demulcent or acidulated drinks; avoidance of exposure to the sun or to cold air; flannel waistcoat and trousers. This treatment, being strictly observed for two months, caused all the inflammatory symptoms to disappear, […]
  1827 May 1, “XXVI. Spreading Ulcer of the Nose.”, in James Copland, John Darwall, John Conolly, editors, The London Medical Repository and Review, volume XXVII, number 161 (New Series, volume IV, number XXIII), London: Printed for Thomas and John Underwood, 32 Fleet Street, page 465
3. (transitive) To use an acidic catalyst, with the chemical change being emphasised over the importance of the change in pH. Used in the processing of biodiesel co-products.