Mumu: A traditional method of slow cooking in Papua New Guinea

P A Sopade, Food Technology Section, Department of Applied Sciences, University, of Technology, Lae, Papua Ned Guinea

One of the traditional techniques in Papua New Guinea is cooking with the mumu. The mumu is an earth oven that is formed by heating stones which are subsequently put in with the food or arranged around and on the food. The heat in the stones is transferred to the food to cook it. The earth oven is known by various names amongst the South Pacific islanders:

· in Samoa, Tonga and Cook Islands it is umu
· in Tahiti it is ahimaa
· in Solomon Islands it is motu
· in New Zealand it is hangi

Generally, black river stones are used and hard wood is preferred as fuel. All sons of food are cooked in the mumu at the same time, but usually the more delicate ones are put on top. The time spent cooking depends on the quantity of food being prepared; it can take anything from one hour to overnight. Mumu is often used during ceremonies, but even households with modem ovens will use mumu on occasions.

Types of Mumu

Papua New Guinea is a land of contrasts; from swampy plains to high alpine mountains and broad upland valleys. Mumu appears to be more common in the highlands, where pottery is very limited. The following types of mumu have been identified;

Rabaul mumu

Alotau mumu

1. Rabaul

In Rabaul a pit is usually dug in which the stones are heated. The size of the pit and the quantities of stones and firewood are dependent on the quantity of food to be 'mumurised'. While the stones are being heated, food is prepared with coconut cream and wrapped in banana leaves. The banana leaves are conditioned over the fire which is heating the stones. The charcoal is removed from the heated stones, and the wrapped food is placed on some of the hot stones. The remaining stones are place on top of the wrapped food before covering the mumu. With banana leaves and jute bags, neither sand nor earth is used and it is usually left for about four hours. All the foods are cooked together and the food is baked rather than steamed as the moisture in the mumu is limited to that held in the leaves and the food. The temperature of the food can be as high as 250°C.

A similar type of mumu was observed in the Western Province (Daru) but no pit was dug and tree bark was used in covering the mumu instead of banana leaves.

2. Alotau

This type of mumu is referred to as dry mumu because, even though the foods are wrapped and cooked together no coconut cream is used in the food preparation. A pit is dug and when the stones are hot. the charcoals are left amongst the stones. The food is wrapped as in the Rabaul mumu and it is put on the hot stones. More hot stones may be put on the food, but more leaves are used to cover the food before the dug earth is used to complete the covering and keep the heat within the mumu. Smoldering firewood is placed on the earth cover to keep the top layer hot.

The additional heat from the top ensures that a high temperature (greater than 200°C) is maintained in the mumu throughout the duration of cooking. The hot charcoals complement this. This relatively constant high temperature is needed to ensure that the food is properly cooked as the absence of coconut cream will reduce heat conduction. As with the Rabaul type. baking is the predominant process.

3. Goroka

This type is typical of mumu in the Eastern Highlands Province. The stones are heated in the pit and most of the charcoal is removed afterwards. Banana leaves are put on top of the stones and the food is wrapped in separate segments. Hot stones may be put in or on to the wrapped food and earth is used to complete the covering. Water is then poured on to the hot stones through a special opening. This generates steam within the mumu. More earth is used for the cover to keep the steam inside. The cooking duration in the Goraka mumu is the shortest, possibly because of the steaming effect. The food appears less baked than in the other forms of mumu and the temperature of the food is usually below 100°C.

Goraka mumu

Mount Hagen mumu

4. Mount Hagen

A different type of mumu is found in the Western Highland Province. A relatively deep pit is dug which is conical in shape. Stones are heated on the ground away from the pit, the bottom and sides of which are lined with banana leaves before some hot stones are put in. Food is transferred separately into the pit and the hot stones are put directly in the food. Coconut cream is not used and neither is water poured on to the hot stones nor are the food segments wrapped in banana leaves. When all the food has been put in, the protruding leaves from the sides of the pot are used in the final food wrapping. Grasses and additional banana leaves are used for the final covering to keep the heat within. Baking is expected to be the predominant form of cooking.

The temperature in the mumu can be as high as 250°C and because of contact between the stones and the food, the food approaches the temperature of the stones. The high food temperature demands that the mumu is uncovered within a short time to prevent over-cooking. It is unusual for this type of mumu to be left overnight. A similar type of mumu has been recorded in Western Samoa, but coconut cream was not used and no pit was dug.

Discussion

Mumu is pan of the culture in Papua New Guinea and the field study revealed that mumu is cherished by the people. Mumurised foods are reportedly rich in flavour and are preferred to foods from conventional ovens for this reason. In theory, cooking foods in a mumu seems convenient, but in practice it is very labour intensive. Concerns have been raised concerning the fire hazard and environmental implications of the mumu materials. However, the major concerns must be the undercooking and overcooking of food and post cooking contamination, as well as migration of materials from stones to foods. At present laboratory tests are being used to examine temperature distribution in the types of mumu discussed above and associated microbiological issues.