I used to think that this recipe was a hoax. I'd seem multiple iterations of it online (even a science fair project on it), but I just couldn't get it to work. I knew there was at least some substance behind, so I tried half a dozen time and finally succeeded!
Things you need:
- Consumables: old/mature ginger, milk (EDIT: I can only get micro-filtered milk to work; pasteurized doesn't seem to set), sugar
- Tools: Instant read thermometer, bowl, grater, sieve, something to heat milk in, something to cover the bowl with
- Cut and peel chunk of old ginger (the type that does not have green/pink shoots sticking out of it).* You want a chunk that is about 10 grams (1/3 oz.)
- Extract the ginger juice. Here, I grate it up and press it through a sieve, but you can use any other method that you like (so long as you don't cook the ginger). You should have about a teaspoon of ginger juice.
- Put a 1/2 cup of milk (and about 1/2 tsp of white sugar, to taste) in the microwave and heat until it reaches 85 degrees C (185 F).** The time in the microwave will vary. It takes me just under a minute and a half. The best way to do this is check the temperature every 30 seconds or so. If the milk exceeds 85 C, let it cool back down before proceeding. If the temperature is too high, the magical ginger enzymes were be destroyed!
- Quickly pour the hot milk into the ginger juice.*** Cover and let rest for 5 min. Do not jostle it!
- Uncover and eat!****
* Young ginger does not have the enzymes required to make the milk coagulate and turn into pudding.
** The website I read quoted temperatures between 60 and 80C. I am not sure why this discrepancy exists. Perhaps my Canadian ginger has different enzymes? Perhaps heating to 85C denatures some of the proteins in the milk which allow it to coagulate?
*** Some recipes talk about pouring from a certain height and "pulling" the milk. The pulling of the milk was used by cooks to ensure that milk, which had been boiled on a stove, dropped down to the right temperature. We don't need to worry about that here because a thermometer is used. Pouring from a certain height doesn't really make any sense to me other than ensuring that there is enough agitation for everything to get mixed up. Just pour quickly right into the center of the bowl and you should be fine.
**** Hopefully the pudding will have thickened up by now. In the photo, you can see that I can even rest a spoon on it. If it is still watery and you have followed the instructions to the teeth, it is most likely the temperature of the milk that was off. If it was too hot, the ginger enzymes are dead and there is no salvaging. If it was too cool, there may still be salvation. The only way to tell is to pop the bowl in the microwave for 10 seconds and the check again. Repeat this once or twice, checking for the consistency each time. If the milk was too cool, the custard will set as it heats up in the microwave. (If you heat it for too long, the milk will split and the whey will separate off as if you were making cheese.) If the milk was too hot, you will still have left with gingery liquid milk after a couple reheats. Still pretty tasty though, so just drink and try again!