Chestnut Preserves From The "Little Forest"

["Notes on how to measure:

for every 500g chestnuts, use 1 tbsp baking soda; 60% sugar of total weight peeled chestnuts; a good splash of preferred optional additions.", "Place chestnuts in a bowl and cover with boiling water. Let steep for 30 minutes. This step helps peel the hard shell.", "Carefully peel the hard skin, leaving soft skin in tact. The more soft skin is broken and the nut exposed, the more fragile they become as they braise and may fall apart.", "Place peeled chestnuts in a bowl or the wide bottom pot you'll use to simmer, cover with cold water mixed with baking soda. Let it steep for 8 hours/overnight. This step offsets the bitterness in the skin.", "Transfer the chestnuts with its soaking water to a pot if still in bowl. Simmer for 30 minutes. This is the first cleanse. Skin foam during simmering process. The water will be dark and bitter. Drain. Renew water. Do this a total of three times. The water from the third cleanse should be the color of light red wine.", "After the last drain, gently remove any big veins and skim off patches of fury bits left on the soft skin. You're not removing the soft skin, just tidying it up. The pointed end of a skewer helps this task along.", "Just barely cover the chestnuts with clean water. Add your 60% of sugar. Simmer until all the sugar is dissolved. Right before switching off the heat, add your splash of preferred aroma. Or omit altogether. I added a generous splash of cognac.", "Spoon into a clean jar, cover with soaking syrup and let cool completely before storing in fridge. I placed thin lemon slices inside the jar to infuse as it ages.", "Though it can be consumed right away, the real treat lies in the several-months wait. Try it on the first day and every few days after that; take pleasure in notes that change over time. The longer they sit it the syrup, the stickier, gooier and chewier they transform. It's a good thing."]