The answer to this question strongly depends on whom you’re asking. Today, some winemakers, usually ones who have some sort of financial interest in it, maintain that grape treading was an essential part of winemaking history. However, historians think that this was a very rare practice. Nobody is saying that ancient people didn’t crush grapes using their bare feet to extract the juices. Sadly, humans had a much better alternative to this method for at least 6000 years. We know this because, in 2011, archaeologists discovered an archaic winery that had a wine press back in 4000 BC in Armenia.
We have been making wine from at least 5400 BC, which would suggest that early humans must have had a simple method for grape crushing before the invention of the winepress system and, most probably, that simple method involved using feet. This is also supported by several existing artwork pieces and other references from history illustrating people crushing piles of grapes while they stood in a huge vat. The most notable pieces are from ancient Egypt, where it’s believed that crushing grapes was a part of winemaking. This has been proved by several artwork pieces depicting that.
However, it’s important to know that this by no means was the only step in the grape juice extraction process. Grape stomping is an inefficient method of extracting juice from grapes, and up until very recently, humans didn’t like wasting anything related to food. According to historians, after the grape treading, the ancient Egyptians would then keep the leftover into a large sack. It’s said that poles were tied to sack’s four corners, and by turning them, the rest of the grape juice was extracted from the leftover grapes.
In every civilization where wine presses were used to make wine, there is very little evidence that they also used grape treading; They simply didn’t need to do this and had a much more efficient method to make wine. The only exception that we found was in Ancient Rome, where grape treading was a common way to extract the first juices from the grapes. The Romans believed that the first juices of grapes had special properties, which the rest of the juices did not. Even in this case, it’s said that Romans still used to the wine press system to extract the juices after grape treading took place.
So, winemakers don’t really walk over grapes using their feet because this was an inefficient way of extracting juice from the grapes. But there is still some evidence that this might have happened, but very rarely, mostly winemakers used winepress to extract the juice from the grapes.