Question submitted via the contact form: Is Aperol high in Oxalic Acid?
We don't know what the oxalic acid content of Aperol is.
However, we guess that you ask this because it is believed that Aperol contains rhubarb. The rhubarb used in bitter alcoholic beverages/amari like Aperol is rhubarb root, which is considered safe to consume (the leaves are the problem not the roots or stalks).
More information is on the rhubarb page.
(photo from Aperol Spritz Facebook Page)