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The exploding mumu - a cautionary tale involving geology

Rabaul mumu schematicPETER KRANZ

YOUNG Joseph was an exemplary youngster and he loved his grandparents and did their bidding.

But one day this trust took a disastrous turn.

He had been told to collect some stones from the nearby wara to help make a mumu.

Now, if you don 't know, the mumu is are prepared in a pit with the first ingredient being red-hot stones. But not just any stones - they have to be mumu stones.

Then you pile on banana leaves, meat, vegetables, herbs, coconut milk, more leaves - and cover the whole thing and leave it for a few hours.

But there's an important difference between Igneous stones and the sedimentary variety. Igneous are generally volcanic and have no threads or fissures, as they have been melted hard into one solid block.

Sedimentary stones, on the other hand, are riddled with lines and cavities which can absorb water.

How to tell the difference?

Well Joseph went down to the river to collect some stones for the mumu. He chose the best ones he could see and took them back home.

Unfortunately they were sedimentary.

The mumu was cooking, steam was issuing and the family was gathered for the feast.

Suddenly there was a great bang and a whoosh, and all the relatives were covered with a green smear of vegies, meat and gravy.

Luckily no one was hurt.

Joseph had learned his lesson - don't trust a rock by i's colour.

A sedimentary stone can look like an igneous. But the steam will boil and an explosion will result.

Don't mix your rocks.


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John Kaupa Kamasua

Peter ah yu yet save mumu is the best. People who do mumus have learnt even in traditional days to select the stones carefully.

I am no geologist but I think there is a certain stone that is only native to my mother's people (the Bomai ku tribe )in SineSine. I reckon these stones are the best mumu stones.

We call them kople kraul but dont know the geological name.

Bernard Yegiora should know what I am talking about.

Peter Kranz

Other traditional methods of cooking in the Highlands - which give excellent results - are hollowed out large sections of bamboo, with the bottom section intact. Insert hot coals in the bottom, then leaves and food and coconut milk etc, then seal the top and leave to steam for an hour or so.

Also works with a hollowed out tree stump.

I still reckon we could make a go of a PNG restaurant in Australia using traditional cooking methods. Its worked for other cultures' cuisines. Unfortunately the name 'hard rock cafe' is already taken.

Peter Kuruvita has an excellent programme on SBS exploring Pacific cooking methods.

Not to forget the delicious Tolai version - Aigir.

(umu, mumu and hangi are similar methods)

Peter Kranz

Well I hesitate to mention the old expression "to get your rocks off."

Baka Bina

Peter you should mention that even when you heat up the stones, any stones will heat up and if the structure of the stone is not volcanic, it will burst, sending sharp stone shrapnel missiles.

You don't want to be standing in the way of a shrapnel.

All stones before they can be mumu stones must be fired first. This blackens that stones (don't ask me about the geology of this) and makes them less propensity to exploding.

Volcanic stones also retain the heat longer than sedimentary stones and, for the highlanders who must produce steam in their heavy duty mumu, the stones must be volcanic.

There is a greyish coloured stone with white dots in them that the highlanders use for their mumu but the nambis lain have a lot of volcanic stones.

Robin Lillicrapp

Most definitely concerted preparation. A stony visage helps with avoiding distraction, and a rockabilly for the tea is a must.

Michael Dom

Does this method of food preparation require the application of 'hard-rock' in good quantity (e.g. AC/DC)?

Robin Lillicrapp

Thereby arguing for the application of rock et science.

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