Carolyn Nadeau's translation of Francisco Martinez Montino's The Art of Cooking, Pie Making Pastry Making, and Preserving:

Page 515

Elderflower Vinegar

Gather elderberry flowers and put them in a basket. They should be packed together and let them rest twenty-four hours. Then over a cloth or tablecloth, begin shaking the flowers over it and the little flowers should fall off and the bare stems with no flowers should remain. Then, set the flowers aside to dry, but without direct sunlight, because that takes away its flavor. When the flowers are thoroughly dry, take six quart glass carafes and put as many flowers inside as you can hold in two hands. Fill with good white vinegar and seal it with the appropriate cork and parchment paper. Then set it where it will be exposed to sun and evening dew and leave it until all the flowers are on the bottom of the carafe. Next, decant the vinegar into other carafes, tightly cork them, put damp parchment paper on top, and tightly tie them up so none of the vinegar’s sharpness escapes. Then, you can refill the carafes where the elderberry flowers are, seal them with cork and parchments, and two months later, you’ll have another batch of elderberry vinegar that is almost as good as the first. This will last all year. If you want to add to each carafe three of four carnations, they should be thoroughly dry. This will give it a clove flavor. If you want to add three or four little dried rose buds, you can also add them, and it will give it a very good flavor.

Redaction:

Separate elderflower blossoms from the stems.

Put in white vinegar in a jar.

Set the jar outside until the blossoms sink to the bottom of the jar.

It took from June 18 to October 4 (108 days) for the blossoms to sink.

Strain off flowers and bottle vinegar.