Recipe ID: 1589527 is where you can find the red wine version.
See Recipe ID: 2012676 for chestnuts simmered in their inner skins.
Also see Recipe ID: 2373598 is another recipe for simmered chestnuts.
Also see Recipe ID: 2360503 for the sake version.
Put the chestnuts in an enamel pot and cover with water. Once boiled, leave the chestnuts to simmer for a few minutes, then turn off the heat and wait for the water to become lukewarm.
Carefully peel off the outer shells, trying not to damage the inner skin of the chestnut. Add them back to the pan with enough water to cover and 1/2 teaspoon baking soda and bring to a boil. Simmer until the liquid in the pan starts to turn red.
Place the chestnuts in a dish of cold water, and keep soaking them while rubbing away as much of the inner skin as possible with your hands.
Repeat Steps 2 & 3 and use a toothpick to carefully remove any thick fibers. Check to see that the chestnut is cooked.
Add the chestnuts and the ingredients marked with ● to the enamel pot and cover with an aluminium foil (or preferably Japanese paper) lid. Boil on a low heat then leave to simmer for 15-20 minutes and cool. Repeat this Step 3 times.
After the 3rd time, leave the chestnuts to soak in the liquid overnight for extra taste (if using an aluminium foil lid, remove it, if using Japanese paper, keep it on). If the room temperature is quite high, then leave them in the fridge.
Once one night has passed, put the chestnuts and juices in a jar and store. They will last a short while in the fridge but if you put them into a sterilized container and put them in the freezer they will keep for longer.
Story Behind this Recipe
I usually simmer chestnuts in red wine, but fancied trying white wine this time.
By adding these chestnuts to a plastic bag (with no top) and placing them in the chilled compartment of my fridge for 1 hour, the sweetness increased tenfold. This time I used a whole bottle of wine and didn't add any water. It's best if you have 800 ml of wine, but you can make this recipe with 720 ml as well.