Did millions of eggs make the UST Main Building appear white?

Separating architectural myth from historical fact.

You are stuck in traffic along España Boulevard when your eyes drift toward the iconic Main Building of the University of Santo Tomas. Bathed in sunlight, the massive structure seems almost white against the Manila sky.

Then someone repeats a story many Filipinos have heard before:

“Alam mo ba? Kaya maputi ’yan kasi may itlog sa ginamit na halo noong itinayo.”

It’s one of those urban legends that sounds just believable enough to survive for generations.

But historical records and architectural evidence do not support the claim.

The myth likely stems from a real chapter in Philippine architectural history. During the Spanish colonial era, builders sometimes mixed egg whites into argamasa, a lime-based mortar used in the construction of churches and stone structures. The practice has long been associated with heritage landmarks such as Baclayon Church in Bohol and other centuries-old religious buildings.

The UST Main Building, however, belongs to a completely different era.

Designed by Fr. Roque Ruaño, O.P. and constructed between 1924 and 1927, the building rose during the American colonial period, when reinforced concrete and steel had already become standard construction materials. By then, modern Portland cement had largely replaced the lime-and-egg mixtures associated with earlier Spanish-era construction.

There is no evidence that eggs were used in the construction of the Main Building.

The building’s light-colored appearance also has a far simpler explanation. The structure is made of exposed reinforced concrete that has weathered over nearly a century. As the material ages, it develops a pale gray tone that reflects sunlight strongly. Under Manila’s intense tropical sun, the façade can appear almost white from a distance.

Special lighting during university celebrations further reinforces that impression. On many occasions, the Main Building is illuminated in brilliant white to symbolize Veritas or Truth, the Dominican motto of the university.

If anything, the real story behind the Main Building is far more remarkable than the egg myth.

The structure is widely recognized as one of the Philippines’ earliest earthquake-resistant buildings. Inspired by lessons from Japan’s devastating 1923 Great Kantō earthquake, Ruaño designed the building as a series of independent structural sections capable of moving during seismic activity.

Nearly a century later, the Main Building remains one of the country’s most important architectural landmarks, having survived war, earthquakes, and generations of Thomasians.

So the next time someone points to its bright façade and says it was made white by millions of eggs, the evidence suggests otherwise.

Its pale appearance is primarily the result of exposed reinforced concrete, natural weathering, and the way the material reflects sunlight—not breakfast ingredients.

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