Home   Calendar   Holidays   Fun Holidays   Sourest Day
World Time
Time Made Simple, Anywhere

Fun Holiday – Sourest Day

October 25 is Sourest Day, a day to celebrate all things sour – people or foods.

25 Oct
Sourest Day
Sunday, October 25, 2026
Add to calendar
Young boy eating a lemon.
Take a bite of sour tasting foods on Sourest Day.
©iStockphoto.com/pohreen

The origins of this made-up holiday are unknown, but we can assume that the day encourages people to try our sour foods and to cheer up the sour people in their lives.

Sourness

Sourness is a taste that detects acidity in a food item. Scientists rank substances on their sourness by comparing it to hydrochloric acid, which has a sourness index of 1.

Souring

Souring is a cooking technique that introduces acid to a food item and changes the chemical and physical properties of the food item. It is often used to make certain types of cheeses and yogurts.

The word sour is also used to refer to someone who is angry, disagreeable or irritable. A person who harbors resentment or disappointment is also sometimes called a sour person.

How to Celebrate?

  • Replace your daily beverages with sour beverages like limeade, buttermilk and drinking vinegar.
  • Have sour tasting food all day long. Have sour fruits for breakfast and for lunch have lemon chicken. For dinner make some ceviche, a grapefruit salad and a key lime pie for dessert.
  • Bring sour candy to work for your co-workers or make a dessert that include sour fruit or limes.
  • Know someone who is grumpy and grouchy? Do something nice for them to make them feel less sour.

Did You Know…

…that an average adult has about 10,000 taste buds in their mouth? Taste buds reduce in number as people age.

Sourest Day Observances

Year Weekday Date Name
2025 Sat Oct 25 Sourest Day
2026 Sun Oct 25 Sourest Day
2027 Mon Oct 25 Sourest Day
2028 Wed Oct 25 Sourest Day
2029 Thu Oct 25 Sourest Day
2030 Fri Oct 25 Sourest Day
2031 Sat Oct 25 Sourest Day
2032 Mon Oct 25 Sourest Day
2033 Tue Oct 25 Sourest Day
2034 Wed Oct 25 Sourest Day