For Daniel.

1. Make cider. Back in 2001, when I was moving to Portland, Jesse Hix gave me a recipe that I have loved ever since: get fresh-squeezed, unpasteurized apple juice in a bottle (or, better yet, squeeze it yourself, especially if you live in Sweden and there is a bounty of apples falling from the trees). Getting cider yeast from a brew shop is great, but bread yeast will do the job; add some sort of yeast to your juice. (I suspect that you could use the natural yeast from the apple skins, too, which would be amazing.) Then, get a party balloon, dip it in a 10% bleach solution to kill any bacteria on it, and place it over the bottle opening, as if you were going to fill it like a cider balloon. Place it somewhere warm. The yeast will start eating the sugars and produce alcohol and carbon dioxide; the gas will fill the balloon; the balloon will inflate. At the same time, a small amount of gas will escape every day. As the sugar is used up, less sugar will be available for the yeast and less gas will be produced. Eventually, the balloon will collapse; this is when the fermentation is done. If you are going to bottle it, Jesse suggested adding a spoon of sugar to a bottle, then pouring the cider on top; it would carbonate naturally as the new sugar was consumed.
2. An alternative, inspired by Iain: make tepache by mixing 100g of dark brown sugar with 1L of boiling water, then letting it cool. Cut the sides of a pineapple off, then the flesh, and put the flesh aside. Cut the sides up, then cut the core up into thin strips, and put it in the cooled syrup. Add cloves, cinnamon, nutmeg, anise, etc. Place this inside a clean glass jar and let it ferment for a few days, or a week, or more. Stir it, making sure that the pieces of fruit get submerged regularly. Take out the fruit after a few days, but let it continue to ferment.
3. Or make tepache, then use the tepache as a yeast starter to make ginger beer like Karel used to drink when he was a teenager. Put 100g of sugar and 1L of water in a slow cooker with a lot of sliced ginger, and maybe cardamom, cloves, cinnamon, etc., and let it cook for…I don’t know, four hours, or overnight. Drain out the hard stuff, let the liquid cool, and add it to a glass jar with a bit of tepache and let it ferment.
4. Another alternative: buy cider.
5. Now you have some sort of alcoholic beverage. I recommend this recipe for making cider vinegar, but the TL;DR route: pour the alcoholic drink into a one-liter jar and add a mother of vinegar. If you do not have mother, allow a fruit fly to land on the liquid, then kill the fly and let it soak in the liquid for a bit, then remove it (if you don’t want fly in your vinegar, that is). The acetobacter that lives in the mother, or on the fruit fly’s legs, will start consuming the alcohol and reproducing. The byproduct will be acetic acid.
6. Oh, and for jars: I prefer Le Parfait, Arc, or Le Practique 1L flip-top jars; better yet, a 2-3L jar will give you more surface space for aeration. (If you get any used French canning jar on eBay or at a flea market, it is going to be perfect.) The ring that goes around these jar tops has enough leeway to pinch the cheesecloth or cling film and still close around the top. I find that IKEA and Kilner jars tend to have tighter rings (using less metal to save costs, perhaps), so it never clasps properly when you try to connect the ends with cheesecloth underneath.
7. Cover the opening with cheesecloth to prevent other insects from getting in, put the metal ring around the lid of the jar, fasten it, and leave it to sit for about a month with the lid off. Check it every few days; if the mother builds up on the top in a thick layer, just push it down to the bottom, where it will stay. Because acetobacter needs oxygen, some people suggest using an aquarium bubbler to aerate the liquid; this can, apparently, reduce the time needed to make vinegar from a month to a week. I find that whisking the cider into a froth every couple of days accelerates the conversion into vinegar for far less cost, and whisking anything into a froth is fun for kids to do.
8. Oh, and you can use beer instead of cider. A mango IPA or a chocolate stout adds interesting tones to a vinaigrette, too, and can be paired with salad ingredients – mango IPA vinegar with peaches and nuts, or a reduced chocolate stout vinegar with pears and walnuts, for example.
9. After a few weeks, try your vinegar. If it tastes tart, it’s good.
10. Once the vinegar is ready, make a brine with 50g salt and 1000g boiling water. Let it cool.
11. Get a head of garlic, peel each bulb, and set them aside in a bowl for a minute.
12. Get some ginger. I could suggest an arbitrary amount, but…use as much as you think is good. Peel it, then slice it and add it to the garlic in the bowl.
13. Get a lot of chili peppers. Use a kind that you like. It is usually better to buy them from an independent grocer, because you can get them by weight instead of the small packages sold at supermarkets to rank amateurs who only consume, say, 10 Carolina Reapers with their blueberry pancakes. Cut the stems off, then put them in a new 1L jar so they mostly fill it.
14. Add the garlic and ginger on top so that it is maybe 1cm below the edge of the jar. If the peppers are on top, I find that they are so light that they push out of the brine more easily, whereas when the garlic is on top, it pushes everything down. This could be a figment of my imagination.
15. Alternately, put everything in, then slice some raw beets and put the slices on top so they push everything down.
16. Pour the cooled brine into the jar until it is to the edge, or just below.
17. Pull off a big square of cling film. Put it over the jar, and push it down so that it covers the liquid. Allow it to fall around the sides, and then put the ring of the jar on so that it pinches the cling film all around. The point is to keep the vegetables submerged, which helps prevent mold from forming.
18. Put the jar on a plate or bowl to catch any dripping liquid, and put a small glass cup on the cling film to push the peppers, garlic, and ginger down under the brine. For this, I like Duralex glasses; they have rounded edges, and I believe – without any evidence – that they are reinforced glass, so if they fall, they will not shatter as easily. Also, they are French glass, and I somehow, apparently, developed a strong bias for French glass.
19. Wait. The lactic acid bacteria on the peppers will thrive in the brine and produce bubbles. The bubbles will rise, and push liquid out of the jar into the bowl or plate, and push the glass cup up. Once every few days, take the cup off, un-clasp the ring, gently pull the cling film off, and replace the cling film on the pepper mixture so that there is very little air inside, then seal it up again. Bubbles will form, the glass will be pushed up, liquid will escape. If you do not put the jar on a bowl or plate, the liquid will soak into your wife’s grandmother’s antique sideboard that she gave you when she moved into her nursing home, discoloring it horribly, as if you’d poured acid onto it in a perfect circle, and you will need to either refinish the top (which is difficult if it is well-loved and the corners are perfectly worn by generations of casual bumps) or hide it by placing an old wine crate on top and pretending it is there to hold things of value and import, adding heavy or awkwardly-shaped and delicate things whenever your inlaws visit.
20. Once the liquid is cloudy, drain the brine into a bowl and put it aside.
21. Put the pepper/garlic/ginger pieces into a blender. Add one cup of vinegar and one cup of brine, and blend it. The amount of liquid is arbitrary; add more or less as you see fit.
22. The sauce is done.
23. You can try to incorporate the brine into other recipes or just toss it out. Any extra vinegar can be aged for six months to a year, then used, or just used immediately, and the mother can be set aside to make new vinegar.