Mom used to cook rice in palayok (clay pot). It was a good cooking vessel. I had rarely eaten rice that was too dry, too wet or burnt. She was also using it to cook other dishes especially the slow cooked sinaing na tulingan. However, the clay pot posses one great disadvantage, fragility. It was extremely sensitive to drop and other slight forces. A drop from one inch height is enough to cause breakage. The risk of wasting food is high.
Mom gradually replaced all palayok with steel cauldron, the gray colored kaldero. I think it is made of cast iron or an alloy resistant to rusting. I rarely see a rusty kaldero. It’s a fragile metal but not as sensitive as palayok. Dropping the vessel from a height of five feet might break it depending on floor type and position of vessel on impact. Some cauldron contains holes. Perhaps manufacturing flaws that can only be observed after few consecutive uses. A cheap metal strip is sold for a very cheap price. Especially manufactured to cover cauldron holes. The bottom always gets black. Wooden stove cooking will make it black in a jiffy. The sides get a lighter shade. LPG stove will also blacken the bottom slower over a long period of use. Probably a carbon deposits from firewood and metal degradation. Scrubbing the blackened surface is not recommended. Doing repeatedly gonna thin the metal and shorten the cooking equipment life.
Clay pot also suffers from this blackening syndrome. Scrubbing the bottom will also thin the clay and shorten its shelf life.
Cooking rice in both medium entails the same technique. Wash the rice three times or until the last washing is clear. Place in kaldero/palayok and add same volume of water. One measure rice + one measure water by volume. Set the fire and let boil. Boilings causes partial opening of cover releasing water vapor and water. Lower the fire when bubbling commences. Set it to lowest setting when bubbling ceases. Turn off if rice is well done.
When bubbles start to get fewer. The vessel can be opened to see rice status. Add more water if the rice is too grainy or hard, scoop out excess liquid or leave as is. This is done only if the exact rice to water ratio is unknown. Opening it too often often ruins the end result.
Based from my observation, the trick for cooking large quantity is different. During our stay-in ROTC training, one of my batch mate cooked rice using a large cauldron. It could accommodate more than five kilograms. The result was a real mess, unevenly cooked rice. The bottom was burnt, the sides are well done and the center and upper portions were raw.
I can only cooked rice with a regular household cauldron of about 3 to 4 gatang capacity. Gatang is a non-standardized unit of measurement for volume. Empty milk can is the popular choice. Size depends on one’s preference. Some are using plastic cups, drinking glass or ceramic mugs. Modern electric rice cookers use cups instead.
Large rice quantity is usually cooked in tulyasi. Equal amounts of washed rice and water are placed in the large vessel. It is continually stirred until water is almost all absorbed. Banana leaves are then placed as cover. Wood fire is set to low until the rice is well done. It is tricky and requires a good judgment.
The electric rice cooker. It is a device invented for the sole purpose of cooking rice. Though other dishes can be cooked in it, like nilaga, bulanglang and soups. Using one is the lazy way to cook rice, the convenient way rather. It also involves washing and measurements but removes further user intervention. Less mistakes provided that measurements are more or less accurate. Place in equal measures of rice and water. Plug the cooker and set. The heating coil will boil the water and rice mixture. When all the water is almost all absorbed, the temperature will rise beyond 100ºC and will trigger the off or stay warm switch. Getting a too wet or gritty rice is likely but burnt is not.
Unlike manual cooking, commercial e-rice cookers (capacity of 3.7 to 5.5 kg, 20 to 30 cups) are able to perform as good as home e-rice cookers.