What do feta, cucumbers and cottage cheese have in common?

Social media and the internet are changing how people cook and relate to food.

First they came for the eggs. Then the feta cheese, caviar, cottage cheese and cucumbers. In some countries, these ingredients even sold out: Iceland experienced a shortage of cucumbers, and feta briefly vanished from grocery store shelves. The reason for the raids? Aficionados of online cooking were eager to recreate viral videos in which each of these ingredients starred.

Few topics are as appetising to netizens as cooking, especially over the holidays. Food is the fourth-most popular subject on the internet (trailing only films, music and phones), up from 17th place in 2009, according to GWI, a consumer research firm. No other subject's rank has risen by more in the past 15 years, besides sport (though it remains less popular than food).

The abundance of online food content not only causes occasional ingredient shortages when a video goes viral. It is also making cooking more social. TikTok videos starring chow attract tens of millions of viewers. Mukbang (eating broadcast) videos, in which people gorge in front of a camera and field live comments from viewers, started in South Korea but have spread to the West and are now popular globally.

The internet has propelled people without notable restaurants or cookbooks to chef stardom. For example, around 21 million people subscribe to the YouTube channel of Nick DiGiovanni, a 28-year-old Harvard-educated food personality, about the same number as subscribe to that of Gordon Ramsay, a famous British chef.

That social media has caused interest in food to rise as fast as home-baked bread should not come as a surprise. Everyone has to eat, and cooking is a common hobby. Video is also an efficient medium for instruction - more precise, in many ways, than the written word. Americans who recently cooked turkeys for Thanksgiving can testify that "golden brown" to one cook may look underdone to another and even burnt to a third.