On the Trail of the Phoenix – Cleaning Old Brass Moulds
Chinese New Year is around the corner and for many of us, the baking and making of Chinese New Year cookies and other delectable goodies has started. It is barely a month from all that Christmas cooking and feasting, and just when we thought that we could rest our ovens and stomachs for a while longer, it is time to get busy again! But this is no surprise as once Tang Chek is past, traditional households look forward to the coming of “Chun” (spring) and of course Chinese New Year celebrations. Time to take out all those kueh moulds which had been kept away over the last year and for some, even longer. Wooden moulds to tekan kueh koya and cutters and crimplers for kueh bangket (kuih bangkit), aluminium or steel clam-shell moulds for kueh belanda (kuih kapit) and of course the heavy brass ones for kueh baulu (kueh bolu or kuih bahulu). Let’s not forget the tortoise-shaped wooden moulds for making kueh koo (angku kueh) for sembayang tikong on the birthday of the Jade Emperor which falls on the 9th day of the Lunar New Year as well! Many peranakan households still have old moulds which have been handed down over the generations, used by the bibiks of the past to whip up all those popular snacks which are enjoyed over the festivities. My personal favorites are the kueh baulu moulds incidentally, so its a good time to take them out for a good scrub amidst all that spring cleaning to be done!
When it comes to cleaning old brass moulds, there are various schools of thought. Commercial metal polishes like brasso and autosol are generally no-nos, due to their toxicity. Food grade ones for pots and pans are generally frowned upon as well, not wanting to take the risks of poisoning your guests with these dainty little sponge cakes which might have been carelessly laced with the remnants of the metal polish if extra care was not exercised to ensure their cleanliness and integrity. One of the most widely used and well circulated methods amongst vintage ware collectors for cleaning old brass moulds seems to be the use of tamarind, tapping into the acidity of these tropical fruit to work on the tarnished surfaces of the moulds. “Ayer asam” as it is commonly known works of course but the peranakans of the past, with much ingenuity devised another method of cleaning old brass moulds using pineapples instead! Needless to say it worked beautifully and I must say, quite satisfyingly as well!
The principle behind the use of pineapple in cleaning moulds is basically the same as tamarind, i.e. the natural acids in pineapple juice. Citric acid and ascorbic acid specifically, amongst traces of other types of acids which may be present to help corrode and remove the oxide layers which result in the tarnish. Apart from that, fresh pineapple pulp is packed with bromelain, an enzyme which function well as a meat tenderiser, and may perhaps have some kind of positive effect on working on all that kitchen grime accumulated on the moulds over the years as well. No scientific proof on the latter of course but who cares! I doubt anyone would be bothered too much by the science behind it as long as it works! The nyonyas of the yesteryears most certainly weren’t anal retentive enough to go about discovering the science behind it all. All they did was to make sure that the pineapples helped to clean their moulds well enough for them to make smackeroo kueh baulus! Since Chinese New Year is barely two weeks away, it is kueh tair (pineapple tarts) making season again! The bits of wastage from the pineapples to make pineapple jam for kueh tair serves well for me to experiment on the effects of pineapple on mould cleaning. The skin which had been shaven off is usually discarded. But it is perfect to be reused as an “al naturale” mould cleaning agent!
Same with the “gorged out” bits of pulp containing the “eyes” and seeds of the pineapple. Not to be wasted as well as these too can be used!
The method is incredibly simple. All I did was to blitz the skin and to-be-discarded pulp with a blender until a loamy concoction was obtained. In a matter of seconds, the pineapple cleaning agent is made and ready for use!
The slurry is then smeared generously onto the surface of the moulds. All that is left to do is to wait! Simply leave the moulds overnight and allow time for the various componentsin pineapple pulp to work its magic! One would soon be rewarded with naturally cleaned moulds!
The second photo in this blog post shows the mould on the left which had already been cleaned while the right one had not. This is done so for the contrast between the two moulds which actually looked almost identically black when I first received them. I cleaned up one and was absolutely elated with the results, being equally astonished by the effectiveness of pineapple pulp as well! Nyonya dulu kala pandey skali! The photo just above shows the mould on the right been cleaned as well. The results are quite apparent. What was interesting for me, was what the cleaning up process revealed. These two old moulds are actual hand crafted, with the markings in the cavities etched up manually and not by machine. The lack of uniformity in the motif somewhat adds on to their beauty and of course the human touch on them bears signature of their age. It is also quite interesting to observe that their base tones are of a different shade, with the left piece being somewhat lighter than the right. This probably stems from the varied compositions of copper and zinc used to alloy the brass used to make these moulds.
Since I had quite a bit of pineapple pulp to work with, I took the opportunity to clean up some of the kueh baulu moulds from my small collection as well. The pineapple pulp did well to remove most of the tarnish and grime, yet leaving behind a trace of patina for one to reminisce and be reminded of the age of the pieces. I actually quite like the idea of the cavities remaining somewhat darker than the rest of the mould, further accentuating the already pronounced outlines on these old fellas. Some folks may feel that these old moulds are pieces of antiquities and should not be cleaned up, allowing their original patina to reflect their age. But I think that these pieces of kitchen utilitarian ware should continue to be used whenever possible, in hope that these common practices of the past will become an extension of the cultural and culinary heritage for us in the present. Cleaning them up is merely reinstating them to their former glory.
For a more pragmatic reason, these moulds probably work better than the currently available ones which are made from aluminum. The former is copper based and thus naturally a better conductor of heat than brass itself. The layer of clay plastered onto the bottom of these old moulds would also mean that heat distribution would be more uniform. Finally, the etched out designs in the cavities of these moulds made long ago seemed to be significantly more pronounced thus allowing the kueh baulu produced to have more well-defined imprints on them.
Now that the moulds are properly cleaned up, they are ready to rock and roll in the kitchen for some kueh baulu! All I need now is a good o’ recipe which churns out those nostalgic kueh baulu which are crisp and crusty on the outside and soft and spongy within. If you have a good recipe to produce such kueh baulu, please share it with me!