Peel ginger and turmeric root. (Peeling with a spoon is the simplest method and also be aware – turmeric will STAIN EVERYTHING, including your hands. Wear gloves, cover cutting boards and any surfaces.)
Quarter the lemon and chop the ginger root and turmeric into smaller pieces. (if using a blender)
Combine ingredients in a heavy duty blender, and blend until the contents are as pureed/juiced as possible.
Double strain through a cheesecloth and a fine wire mesh sieve.
Bottle and store refrigerated 2-3 weeks.
Notes
If the blender is smaller, divide the ingredients into smaller batches. If you have a juicer that is heavy duty enough to handle the ginger root, juicing the ginger, turmeric, and lemon would be a preferred method.