While peeling improves the flavor of turmeric, you'll not want to do that when you ferment it. We want the beneficial bacteria that grows naturally on the skin, to make fermenting possible. If you absolutely want to peel yours, you'll need to add a couple of tablespoons of starter culture. This can be juice from a previous ferment or whey from strained yogurt or cheesemaking.
Roughly chop the turmeric. If you're using a scale, weigh your food processor bowl, record the weight and tare it to zero in grams. Add the turmeric, record the weight, and process. I used a food processor.
Add peppercorn or fresh ground pepper (the piperin will oxidize quickly and lose its benefits, so don't use ground pepper from a box).
Now calculate your salt. You'll be using 2% of the weight of the turmeric in salt. If your turmeric weighs 400 grams, this is your formula: 400 x .02 = 8. You'll be adding 8 grams of salt. If you don't have a scale, add 1½ tsp per pound of turmeric.
Give the paste another whirl to incorporate the pepper and salt.
Using a funnel, transfer your ingredients into the fermentation jar.
With your pickle packer, or spoon, press the ingredients firmly into the jar to eliminate air bubbles and to submerge the ingredients in the brine.
Cover the ingredients with a fermentation weight or a ziplock baggie that's filled with 2% salt brine. If your jar is only half full, this is actually the best solution, so you can reduce the air space that occupies the jar.
Seal with a fermentation lid.
Place a plate under it and leave it for 10-21 days in a darkish corner at about 70-80℉. 3 weeks is the recommended time for long fermentation. But it will be pretty good after a week.
Maintenance and Observing: Keep a casual eye on your fermentation. You don't need to do anything if it looks ok. It will start to bubble after a few days and might possibly ooze out of the jar. If you see a whitish layer on top, that should be skimmed off every few days.
If you're using a regular mason jar lid, don't forget to burp it every day.
Now you can open it, look at it, smell it. If nothing seems off, taste some. If it's good, take out the weight and top with a regular lid and place it into the refrigerator or cellar. If your turmeric paste is a little dry and your brine isn't covering your ferment anymore, you can add a little brine from another ferment or just add some raw vinegar to cover the ingredients and keep them from getting moldy on top. Most ferments will keep for at least a year. I have kept many of my ferments successfully in a cellar with fluctuating temperatures (35-60 degrees) even for 2 or more years.