You can find the italian recipe on my site http://www.federicoferrazzani.eu/.
Step 1: Ingredients
700 cc of water
40/50 gr of 100% pure liquorice extract
200/250 cc of neutral grain spirit 95%
300 gr of sugar
The liquorice is in the form of small black pieces made only from 100% pure liquorice extract with a bitter and intense taste. When you buy it be sure the only ingredient is liquorice (not sugar or anything else).
Step 2: Procedure
Stir constantly the content to prevent it from burn and to facilitate the dissolution of the pieces. If before we reduce the size of the pieces of liquorice we reduce the times of dissolution, but is not fundamental.
Once all is melted licorice you can add the sugar off the heat and continue to turn to melt it. Cover and let everything cool down.
Once it is cold you can add the alcohol, stirring the whole.
Step 3: In the bottle
Put it in the bottles. It will take 4 or 5 weeks off so it all builds to perfection.
The recipe given is balanced, but as tastes are not all alike, you can modify and customize, for example by increasing the amount of alcohol if you want a liquor a little stronger. But I recommend making changes in small doses.