One note about boiling the herbs – typically the technique of boiling is reserved for hard plant materials, such as roots and wood, while softer materials, such as leaves, are treated more gently by steeping them for long periods of time.
The reason the recipe calls for boiling the herbs rather than steeping is specifically to extract the bitter, healing elements. Yes, the herbs’ water-soluble vitamins are lost because of this, but for cough drops,, the herbs are much more potent when the bitter elements are present – especially in the case of horehound – so simmer away guilt-free. And don’t worry – considering we’re pairing the herbal extract with a super-sweet honey syrup, the bitterness won’t be overwhelming.
If you’d prefer, you can infuse the herbs overnight: Place the dried herbs in a bowl and set aside. Boil the water, then pour over the herbs. Cover the bowl with a plate or lid and let sit for 8-10 hours. Strain well and continue as directed.
IF you have the time you can stee[ 12 the herbs overnight and boil the other half. Combine the liquids of both before adding honey (or sugar) and continue with the recipe as directed.