Hebrew word · H1155

בֹּ֫סֶר

voser

unripe grape

Unripe grape(s), sour grape(s): grapes in the green stage before they ripen. The word is a collective singular here.

Appears 4 times in 4 verses of the Hebrew Old Testament. · Updated October 31, 2026

What it means

unripe grapes, sour grapes

Also means: be.ser (בֶּסֶר "unripe grape" H1154)

Abridged from Brown, Driver and Briggs, A Hebrew and English Lexicon of the Old Testament (1906), via STEPBible.org (CC BY 4.0).

Range of meaning: Unripe grape(s), sour grape(s): grapes in the green stage before they ripen. The word is a collective singular here.
Against the English: 'Sour grapes' (KJV, BSB, WEB, and most modern versions) is accurate in itself, but modern English 'sour grapes' is an idiom from Aesop's fox for pretending to despise what you cannot have. YLT's 'unripe fruit' avoids that.
How it drifted: The English idiom 'sour grapes' comes from Aesop's fable of the fox and the grapes. It entered English from the 15th–17th centuries and later became the dominant meaning of the phrase. The KJV translators' 'sour grapes' predates the idiom's modern dominance.
Used elsewhere in the period: Isaiah 18:5 ('the flower becomes a ripening grape', boser gomel); Job 15:33 ('he shakes off his unripe grape like a vine'); Jeremiah 31:29–30. The Septuagint uses omphax ('unripe grape'), a word also known from Greek agricultural writing for the sour juice of green grapes.

Range of meaning: Grapes at the unripe stage: hard and green, very sour and astringent, meaning they dry and pucker the mouth. Elsewhere it can mean the young grape just forming after the flower (Isa 18:5) or unripe fruit that a vine drops (Job 15:33). Later Hebrew still uses boser for unripe grapes or fruit.
Against the English: KJV 'a sour grape' and most modern versions' 'sour grapes' sound like a kind of grape that is sour. The word is about ripeness, not variety. YLT's 'unripe fruit' is the most precise. The English idiom 'sour grapes' adds a meaning of its own that has nothing to do with Hebrew (see drift).
How it drifted: The modern English idiom 'sour grapes' comes from Aesop's fable of the fox who calls the grapes he cannot reach sour. That idiom means sneering at what you cannot have, and it now crowds out the agricultural picture.
Used elsewhere in the period: Hebrew Bible: Isa 18:5; Job 15:33; Jer 31:29–30; Ezek 18:2. The Greek Old Testament (Septuagint) uses omphax, the normal Greek word for an unripe grape. The Vulgate has uva acerba, 'harsh/bitter grape'.

Isaiah · 1

Isaiah 18:5 וּבֹ֥סֶר and unripe grape[s]

For before the harvest, when the blossom is gone and the flower becomes a ripening grape, He will cut off the shoots with a pruning knife and remove and discard the branches.

Jeremiah · 2

Jeremiah 31:29 בֹ֑סֶר sour grape[s]

“In those days, it will no longer be said: ‘The fathers have eaten sour grapes, and the teeth of the children are set on edge.’

Here: Green, unripe grapes (singular used for the whole crop). Eating them early is greedy, foolish and harsh in the mouth. It stands for the ancestors' sin.
Jeremiah 31:30 הַבֹּ֖סֶר the sour grape[s]

Instead, each will die for his own iniquity. If anyone eats the sour grapes, his own teeth will be set on edge.

Ezekiel · 1

Ezekiel 18:2 בֹ֔סֶר sour grape[s]

“What do you people mean by quoting this proverb about the land of Israel: ‘The fathers have eaten sour grapes, and the teeth of the children are set on edge’?

Here: Grapes picked green, before they ripen. They are intensely sour and astringent, and eating them is foolish and impatient. The picture is of an act whose unpleasant effects ought to fall on the one who did it.

Word data: STEPBible.org (CC BY 4.0), main text only.