Before you do anything, please ensure you are wearing the appropriate protective clothing, including gloves and goggles. Do not let the lye mixture or the finished soap mixture touch your skin or you may get a lye burn. Keep pets and young children away. Work in a well ventilated area.
Slowly add the lye into the water and stir until dissolved. Set aside to cool. While your lye mixture is cooling, melt all your oils and butters together. Let the oil mixture also cool. Once both the lye mixture and the oils mixture have cooled down to around 50℃ (or lower but ideally within 10℃ of each other), slowly add the lye to the oils and blend with a stock blender until trace is reached. Add the activated charcoal and blend to incorporate, then add the essential oil and blend. If you like you can also add in some clay (this will make the soap lovely and creamy) but this is optional. Pour the soap batter into molds, tapping them to release any trapped air bubbles. Then insulate your soaps for at least 2-3 days, allowing them to harden up. Once they are hard you can remove them from their molds and leave to cure for at least 6 weeks.