Add to ORKGThere has been a long history of applying organic additives (OA) in mortars, and an understanding of both their historical uses and the scientific study on them is fundamental to produce restoration materials which are compatible with historical mortars. In this paper, a critical analysis of literature is given, on both characterisation studies of historical mortar samples as well as studies of laboratory-made mortar specimens. By doing so, we hope to provide more insight to future work in the field of architectural conservatio