Homemade Cough Syrup
Coltsfoot, Slippery Elm, Horehound (expectorant & demulcent), Thyme (expectorant), Marshmallow (demulcent), Anise, Eucaplytus.
Make a tea using 1 ounce (6 teaspoons) of dried herb to 1 litre of water. Place the full ounce of dried herb into the litre jar and fill it to the top with boiling water. Cap tightly. After 4-10 hours, decant your infusion, saving the liquid and squeezing the herb to get the last of the goodness out of it.
Measure the amount of liquid you have (usually about 3½ cups). Pour this into the saucepan and bring to a boil. Reduce the heat until the infusion is just barely simmering. Continue to simmer until the liquid is reduced by half (pour it out of the pan and into the measuring cup now and then to check). This step can take several hours; the decoction is not spoiled if it is reduced to less than half, but it is ruined if it boils hard or if it burns. Keep a close eye on it.
When you have reduced the infusion to less then two cups, add 1.5 cups of honey and bring to a rolling boil. Pour, boiling hot, into your jar. (Sterilize the jar by boiling it in plain water for a few minutes just before filling it.) If desired, add some vodka to preserve the syrup.
Allow the bottle of syrup to come to room temperature. Label it. Store it in the refrigerator or keep it in a cool place.
Adapted from http://www.ashtreepublishing.com/bookshop/articles/herbal-expert-part8.php