A-to-Z List of Essential Oils with a Slightly bitter Aroma:
Aroma Description: Rich, spicy, sweet, soft, warming yet slightly bitter. It is also slightly woody in character and is reminiscent in aroma to that of true clove buds but is of course much stronger in aroma.
(Citrus × aurantium)
Aroma Description: Citrusy. The aroma is tangy like grapefruit, but yet is sweet. It is reminiscent to the aroma of the grapefruit rind, but more concentrated.
Aroma Description: Strongly herbaceous, earthy, effervescent green aroma with a slightly bitter, penetrating high note and a clean herbal body note; its long herbaceous drydown is very tenacious
Aroma Description: Fresh and sweet with a somewhat sharp (bitter), earthy/herbaceous aroma.
Aroma Description: Balsamic, Earthy, Herbaceous, Pungent, Resinous, Rich, Slightly bitter, Slightly musky, Slightly spicy, Strong, Warm, Woody
Orange, Bitter (Petitgrain)
(Citrus × junos)
Aroma Description: As the name implies, Bitter Orange Essential Oil smells like a cross between the sweetness of sweet orange oil and the slight bitterness of grapefruit oil.
Aroma Description: Astringent, Coniferous, Cool, Earthy, Exotic, Herbaceous, Pungent, Slightly bitter, Woody
Aroma Description: Very subtle aroma, mildly sweet, tart and earthy
Aroma Description: Balsamic, Earthy, Exotic, Sensual, Slightly bitter, Slightly spicy, Strong, fruity, alluring