• 酉(wine vessel; ferment)
• 夋(slow manner; leisurely pace)

Fermenting alcohol produces sourness, which is exactly the character for sour.

• 黃(yellow; ripe grain field)

A mature golden rice plant with its stalk, roots, and heavy drooping grain panicles forms the image of this character.

• 瓜(melon; gourd (pictograph))

The character 瓜 depicts a melon hanging loosely from a vine.

• 酉(wine vessel; ferment)
• 夋(slow manner; leisurely pace)

Fermenting alcohol produces sourness, which is exactly the character for sour.

• 黃(yellow; ripe grain field)

A mature golden rice plant with its stalk, roots, and heavy drooping grain panicles forms the image of this character.

• 瓜(melon; gourd (pictograph))

The character 瓜 depicts a melon hanging loosely from a vine.