Bottle caps have become an integral part of our daily lives. Whether enjoying wine and beverages or using them as seasonings in cooking, they are indispensable. The ease of opening and sealing performance of bottle caps vary depending on the material and design; some are effortless, while others require considerable effort. Looking back at history, bottle caps did not exist from the beginning. In ancient times, people typically used natural materials such as clay to seal wine, which gradually evolved into materials like pig bladders. The sealing technology for wine also underwent changes from oilcloth to oak and cork stoppers. Cork stoppers were favored for their tight seal and ability to infuse the wine with oak aromas. Furthermore, their expansion upon contact with wine further enhanced the seal, which is why wine is often stored upside down.
However, for older spirits with plastic caps, storing them upside down requires extra care. The polyethylene in the plastic can react with alcohol, which can easily lead to the loss of flavor and may also produce a plastic odor, affecting the quality of the wine. In contrast, aluminum caps or screw caps have gradually become mainstream due to their superior sealing and convenient opening method. Aluminum caps can be opened with a simple twist, making them easy for both women and men with less strength. However, when facing someone you like, you might suddenly feel powerless and need their help to open the cap for a romantic touch. Of course, this is just a minor incident; wine tasters primarily focus on the alcohol and ethanol content. For this interesting topic of "methanol," perhaps we ordinary people can better appreciate its nuances. Speaking of which, here's a little-known fact: the most widely used bottle cap is actually the beer bottle cap, designed like a crown, combining the advantages of tinplate and a rubber liner. This type of cap was also common in older baijiu (Chinese liquor) from the 1980s, and was known in the old liquor community as a beer cap or pressure cap.