i have been pickling my own kiam chai/hum choy and it has been very satifying as the taste can be adjusted to your own liking. I am sharing my experience and hope that all who are far away from home and good freshly pickled kiam chai/hum choy is not available. Nothing is better than a bowl of hot kiam chai/hum choy soup in a cold winter's day. This soup is also good for the hot summers as the chinese consider salt to 'har for' (cantonese) - in english to douse the fire in you, especially when a piece of tofu is also added to the soup.
4 lbs (kai choy) 芥菜, mustard green, washed & drained
Generous amount of table salt(enough to sprinkle onto the mustard green)
4 quarts rice water,(is water which you use to wash rice, then drain for use. if not, substitute
1 tbsp rice flour) or enough to cover
1 tbsp sugar
Salt(more if you were not heavy handed to begin with when you sprinkle salt onto kai choy initially)
Dried galangal slices
Turmeric powder (about 1/4 - 1/2 tsp)
a large pot or saucepan
a large 4 quart glass bottle
Wash kai choy/mutard green and leave to drain dry
Cut kai choy mustard greens into half, leave in a large colander or several colanders. Sprinkle kai choy generously with salt and leave aside for about 6 hours to draw out the moisture and wilting the kai choy. Discard the drained liquid whilst wilting.
Bring rice water, and the rest of the brining ingredients to the boil. Set aside to cool before using.
After the kai choys have wilted, squeeze as much of moisture from the wilted kai choys and then pack them into a large glass bottle, making sure you firmly press the kai choys down
Using a piece of plastic wrap, push it down the top of the kai choy and to the sides of the bottle. This will help to prevent the kai choys from floating above the brining solution
Close the lid and set aside in a cool place to ferment for 5-7 days.
Check on the greens every day and if you see any whitish bloom on the surface of the brining solution, skim it away(i do not have any, perhaps it is cooler in my kitchen).
After 7 days of brining, the kai choys should have matured, without any visible green. Remove the mustard green without squeezing out any liquid.
Wrap the mustard greens in cling film and store refrigerated in an airtight container.