annually on October 25th (since 1977)
Richard Ankli in 1977
Created by Richard Ankli of Ann Arbor, Michigan, Sourest Day has a twofold purpose: to emphasize the balance of things in nature—on account of its proximity to Sweetest Day and to recognize sour people—because it also honors Ankli's old roommate, Eric Sauer, on his birthday. Contrasts of life are sought, sour people are recognized, and sour food and candy are eaten.
How to Observe Sourest Day
Celebrate by seeking out contrasts in life in an attempt to find a balance of things in nature. If you usually are sweet to others and enjoy sweet food, spend the day being sour and eating sour food. If you usually play it safe, live dangerously. If you like hot food and showers, have them both cold. If you are an early riser, hopefully you got up late today! Recognize all the cantankerous, grumpy, and sour people you know, who likely rarely get any praise. Eat some sour candy like Warheads, Toxic Waste, Lemonheads, and Sour Patch Kids, and eat some sour foods such as lemons, limes, grapefruit, cranberries, rhubarb, vinegar, kefir, kombucha, and sauerkraut.