How do you properly sterilize bottles before filling homemade liqueur?

Expanded Explanation

Properly sterilizing bottles before filling homemade liqueur is one of the most important steps for long shelf life and clean flavor. Sugar, fruit residue, and moderate alcohol levels can still allow spoilage organisms to survive if bottles are only lightly rinsed. Start by washing bottles thoroughly in hot water with detergent, using a bottle brush to remove any film, dust, or trapped residue from previous use.

After cleaning, sterilize the bottles using a reliable method. Boiling bottles for about 20 minutes is a common and effective choice if the glass is suitable for it. Another option is dry heat in the oven after washing, or a rinse with high-proof food-grade ethanol just before filling. Lids, caps, swing-top seals, and funnels should be sanitized as well, because clean bottles can still be contaminated by dirty closures or tools.

Once sterilized, avoid touching the inside of the bottle or drying it with towels. Let bottles air dry in a clean area or fill them while still warm if your process allows it. The goal is not just to clean the bottle, but to keep it free from new contamination right up to the moment the liqueur is sealed.