Which Side of Aluminum Foil Should Touch Food?

アルミホイル (commonly referred to as 錫箔, though not actually tin) is made by pressing aluminum into thin metal sheets. Approximately 75% of its applications are in the packaging of food, 化粧品, and chemical products, making it a very common material in daily life and industry.

しかし, when using aluminum foil to wrap or cook food, many people wonder: which side should actually touch the food?

This is actually related to its manufacturing process—most rolls of aluminum foil sold on the market have one shiny side and one matte side. The essential difference between the two sides is minimal, and there is no obvious impact when used casually in daily life.

But if you want to optimize the usage effect, here are two practical tips. In terms of reflectivity, の matte side has a reflectivity of about 80%, 一方 shiny side can reach 88%. したがって, when cooking, it is better to use the shiny side to wrap food, as it can reflect heat more effectively and speed up the heating process of the food.

If you only use aluminum foil to store food, it is recommended to use the matte side to touch the food first. Because the shiny side has a smoother surface, some sticky foods (such as rice and meat) may adhere to it, affecting access and cleaning.

In addition to this single-shiny, single-matte type, there is also double-sided shiny aluminum foil available. During its single-sheet rolling process, both the upper and lower surfaces come into contact with the rollers, so both sides form a bright metallic luster. If you are worried about choosing the right side, buying this type of aluminum foil can completely solve the trouble.

Aluminum foils of different alloy grades have significant differences in performance and application scenarios. The following table clearly sorts out the core information of common grades for easy selection based on needs:

合金グレード	合金タイプ	Core Characteristics	Application Scenarios
シリーズ 1 (1235, 1060)	Pure Aluminum Foil	Aluminum content ≥ 99%, excellent ductility, 強い耐食性, no harmful alloy composition precipitation, soft texture and easy to shape	食品包装, 料理, baking containers; mainstream choice for daily household use
シリーズ 3 (3003)	Aluminum-Manganese Alloy Foil	Higher strength and wear resistance than Series 1, excellent low-temperature resistance, not easy to become brittle in refrigeration and freezing environments	食品包装, chemical product packaging, refrigerator liner gaskets
シリーズ 5 (5052)	Aluminum-Magnesium Alloy Foil	高強度, tear resistance, 優れた耐食性, and higher high-temperature resistance than Series 1 そして 3	高温調理, barbecue food wrapping, outdoor food insulation packaging
シリーズ 8 (8011)	Aluminum-Silicon Alloy Foil	Balances ductility and hardness, good processability, flat surface, often double-sided shiny	食品包装, high-end packaging for cosmetics/medicines

For household scenarios, priority should be given to シリーズ 1 または 8 アルミホイル, which can better adapt to food contact, 料理, and storage needs, ensuring better safety and user experience.