Sourest Day 🍋

Overview

Sourest Day, observed annually on October 25th, is an unofficial holiday dedicated to celebrating and embracing all things sour. Participants often mark the occasion by indulging in intensely tart foods, candies, and beverages, from puckering lemons and limes to extreme sour candies, challenging their taste buds with a burst of tangy flavor.

Origin and story

It is a modern, whimsical holiday with no known ancient origins, primarily celebrated for fun.

Popular items consumed on Sourest Day include sour candies like Warheads or Sour Patch Kids, and naturally tart fruits such as lemons, limes, and cranberries.

Quick facts

• DateOctober 25
• TypeCultural / community observance
• Great forFriends, Families, Classrooms, Teams

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Ways to celebrate

Scientists didn't actually pin down how sourness gets detected until surprisingly recently. While receptors for sweet, salty, bitter, and umami had long been identified, researchers only confirmed the specific protein behind sour taste, called OTOP1, in 2018 — it acts as a channel letting acidic hydrogen ions flow directly into taste cells, triggering the pucker.

Push your tolerance

• Work through an extreme sour candy a level at a time, rather than jumping straight to the most intense option, to actually notice how the sensation builds.

Read about the discovery

Helpful resources: USC News covers the identification of the OTOP1 protein in "USC researchers determine how sour tastes are sensed by humans."

Taste it in natural forms too

• Bite into a plain lemon or lime wedge, or try unsweetened tamarind, to feel sourness without any sugar cutting the edge off.

Did you know?

Kids generally tolerate — and even enjoy — much higher levels of sourness than adults do, which researchers think is part of why extreme sour candy is marketed so heavily to children and teens rather than grown-ups.

Fun facts

• It is a modern, whimsical holiday with no known ancient origins, primarily celebrated for fun.
• Popular items consumed on Sourest Day include sour candies like Warheads or Sour Patch Kids, and naturally tart fruits such as lemons, limes, and cranberries.
• The holiday encourages people to explore the wide range of sour flavors, from subtly tart to powerfully puckering.

Sources and attribution

• USC researchers determine how sour tastes are sensed by humans (USC News)

External links may lead to third-party websites.

Continue your streak

Open one more holiday before you go to build daily momentum.

• Yesterday: National Bologna DayQuick context from the day before.
• Tomorrow: Mincemeat DayKeep the streak going with tomorrow's pick.
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• Popular: Spouse's DayA fan favorite with broad appeal.

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FAQ

When is Sourest Day?

It is observed on October 25 each year.

What is Sourest Day?

Sourest Day, observed annually on October 25th, is an unofficial holiday dedicated to celebrating and embracing all things sour. Participants often mark the occasion by indulging in intensely tart foods, candies, and beverages, from puckering lemons and limes to extreme sour candies, challenging their taste buds with a burst of tangy flavor.

How do people celebrate Sourest Day?

Work through an extreme sour candy a level at a time, bite into a plain lemon or lime wedge, and read up on OTOP1, the sour-taste protein scientists only identified in 2018.

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