Short answer: It is best to avoid it.

From a Jain dharma standpoint:

• Any drink containing alcohol (madya) is strictly prohibited. If the coffee is infused with whisky or has any alcohol content, it is not allowed.
• Even “whisky barrel–aged” coffee (beans stored in used whisky barrels, then roasted) is discouraged. Though it may have little or no alcohol after roasting, it promotes the taste/aroma of an intoxicant and encourages a rajasic, stimulating habit, which goes against samyam (self‑restraint).
• Tea/coffee themselves are generally discouraged by many Jains because they are stimulants and can foster dependence; during vows/festivals (e.g., Paryushan) they are commonly avoided.

Traditions:

• Shwetambar and Digambar alike prohibit alcohol. Guidance on tea/coffee varies by community and personal vows, but the more disciplined path is abstinence.

For simple references:

• Alcohol in Jainism
• Can Jains drink coffee