Distillation or Best-Before Date Noted on Each Batch

once produced and in bulk containers , each batch of hydrolate should be labelled with the distillation date and all other information necessary to track production. Good distillers may even be able to tell you the field or location that the plants came from by the batch code. This helps identify not only products and sources that are different in quantity but also products that are different in effect. 

Calamus (Acorus calamus) root grown in Europe or Asia contains high levels of the toxic keytone beta-asarone. The Canadian variety is completely beta-asarone-free and therefore safe for use in therapeutic applications. Just as with essential oils, we must know all we can about the hydrosols we use.

Reference: Hydrosols The next Aromatherapy; Suzanne Catty