https://www.usni.org/magazines/naval-history-magazine/2021/february/finding-cure-scurvy

Gilbert Blane was appointed to the staff of Admiral George Brydges Rodney as Physician to the Fleet in 1779. Blane was a medical reformer who was convinced by Lind’s original experiment with citrus and appreciated the need for a practical way of storing them. After considerable experimentation, he determined that adding 10 percent “spirits of wine” (i.e., distilled ethyl alcohol) to lemon juice would preserve it almost indefinitely, without destroying its beneficial properties.