We want to preserve fresh lime juice in bottles for use at home without being spoiled, say, for a month or two.
Ask this in the chemistry section.
All silver will oxydize over time. The air contains minute particles or ions which react with the silver to form the dark coat of oxidation we call tarnish. To remove it the easiest I just spread a slurry of toothpaste and water over the piece and brush it gently with an old soft toothbrush until it comes clean. This is the fastest way I have found to clean silver jewelry. Once the tarnish is removed, I rinse the piece with warm water and dry it with a soft towel or, in a pinch, with a paper towel.
Sterling silver is 97.5% pure silver and 7.5% copper alloy. This copper alloy reacts to humid conditions and acidic skin by tarnishing (brown) and oxidising (black). Lime is a very acidic fruit so the copper in the silver is reacting to the acid in the lime and tarnishing or oxidising. Clean it as soon as possible with a silver polishing cloth.
