1. Why Does Pudding Need Water in the Oven Tray? How an Oven Steam-Bakes Food
Ovens are also called "top fire" appliances, used to steam-bake food [1]. They trap hot air and steam from the food inside the chamber, heating it at over 100°C (about 212°F) [1]. Dictionaries state that for foods needing low-temperature heating, like pudding, you should fill the tray with water [1].
It is thought that water prevents the temperature from rising too high. Water does not get much hotter than 100°C (about 212°F) once it boils. If water surrounds the pudding mold, the pudding warms gently even if the oven air is very hot. This explanation is an interpretation based on reference materials; the dictionary simply says to add water for low-temperature heating.
How can a box of hot air adjust things so gently? First, let’s look at how ovens differ from frying pans and microwaves.
2. How Ovens, Frying Pans, and Microwaves Heat Food Differently
A frying pan heats the bottom surface using heat conducted from below. A microwave vibrates the water inside food using microwaves, making the food itself generate heat [3].
In contrast, an oven keeps the chamber temperature constant and warms the entire food slowly from the outside, wrapping it in heat [3]. Because it traps hot air and steam, food is less likely to burn or become hard compared to direct-fire roasting, according to dictionaries [1].
Manufacturer explanations suggest that because ovens apply heat from four directions, large cuts of meat cook evenly. However, "four directions" is specific to one company’s description; the placement of heat sources varies by model [2]. So, when exactly does this slow, wrapping method work best?
3. What Ovens Are Used For: Baking, Roasting, and Making Gratins
Dictionaries list uses such as baking bread and cakes, roasting, and making gratins [1]. Manufacturer guides also include roasted meats and fish, cookies, and roast potatoes [2].
Looking for common points, we can say three things: First, foods where dough needs to rise or the whole item needs consistent temperature over time. Second, large pieces where the outside might burn while the inside stays raw. Third, dishes like gratins that need browning all over. These three categories are an interpretation of the listed uses, not stated directly in the sources.
Hitachi’s explanation notes that oven heating is suitable for dishes where you do not want strong browning, or foods that take a long time to cook through [3]. The key point is that ovens are useful not just for browning, but also for cooking thoroughly without burning.
4. Heater Ovens vs. Fan (Convection) Ovens: Differences in Browning and Even Heating
Oven heating methods generally fall into two types: those using heater radiation and those moving hot air. One type that moves hot air is the convection oven, which uses a fan to circulate air [4].
One appliance guide explains that in heater heating, radiant heat combines with convection (moving air) and conduction (heat from trays or racks). This balance allows for both outer browning and internal cooking. The way browning forms also changes depending on the combination of top and bottom heaters [5].
Encyclopedia-style explanations state that convection ovens are good for making many dishes quickly, but radiant heaters tend to produce darker browning. Differences depend on the model and dish [4]. Which is better depends on what you are cooking. Some studies show heat transfer numbers, but these mostly study industrial ovens. You cannot apply those numbers directly to home ovens.
5. The History of the Oven: From Cooking in the Ground to Microwave Ovens with Oven Functions
According to dictionaries, the prototype of the oven was a method of steaming-baking food buried in soil. It later developed into kiln-like and brick-built forms [1]. In Japan, countertop ovens appeared from the Meiji era [1].
Microwave ovens with an oven function first appeared in Japan in 1977. Toshiba’s predecessor completed the first microwave model in 1959, and home models came out in 1968 [6]. If a microwave is a box that warms from the water inside, adding an oven function means adding a feature that wraps heat from the outside.
Wikipedia says ovens were first used in Indus Valley Civilization settlements. However, because dates are hard to verify with primary sources, no specific year is given here [4].
6. How to Use Your Home Oven's Manual to Check Its Heating Method and Temperature Range
You can make two observations using the instruction manual for your home oven or oven-microwave.
First, look for whether it says "hot air circulation" (convection) or "heater." Check what temperature range you can set. Manufacturer materials suggest some models can be set from about 30°C (about 86°F) for fermentation up to around 300°C (about 572°F) [3]. It is fun to compare your model’s range.
Second, look in cookbooks or recipes for dishes that require filling the tray with water. Besides pudding, what other dishes use this method?
Always use the oven with an adult present. Wait until the inside and trays are completely cool before touching them. Be careful of burns and follow the safety warnings in the manual.