According to a study published last week in online journal PLOS ONE, our hunger for rich, creamy Alpine cheeses may have begun as far back as the Iron Age.

As Science Daily reports, a team from Newcastle University and the University of York in England examined 30 fragments of ceramic pots found at six different sites in Switzerland’s mountains. The ancient fragments dated from Neolithic times to the Iron Age, and were uncovered from the remains of stone buildings similar to ones used by today’s alpine cheese maker for cheese production during the summer months.

An analysis of the Iron Age pottery fragments revealed they contained residues of compounds produced when milk, produced from cows, sheep, or goats, is heated. As New Historian reports, experts think the vessels could have been used to warm the liquid, which is an essential step in the cheese making process.

The study sheds new light on the origins of mountain cheese making in Switzerland. The food is one of the country’s greatest exports, and an important part of its economy. In fact, half of Switzerland's milk yield goes into the making of cheese. However, little is known about the early history of Alpine cheese making because the region’s archaeological sites are poorly preserved.

While experts have previously found evidence of early cheese production in lower altitudes, they didn’t know much about when—or why—our ancestors started making the Swiss staple in the mountains. They now say that alpine dairying may have coincided with a time when increasing population and the growth of arable farming in Switzerland’s valley pastures drove animal herders up into the Alps.

Ancient humans may have felt compelled to make alpine cheese for several reasons, Quartz reports. It could have served as a high-protein food during the winter months, or it might have been a less land-intensive food to produce in the rugged mountains. Our dairy-loving ancestors might have also made and consumed cheese to show off their social status. Since cheese is difficult to make, eating it demonstrated wealth and affluence.

[h/t Science Daily]