Organic material like bread typically only stays preserved after undergoing carbonization. Credit: Canton of Aargau Get the Popular Science daily newsletter💡 Breakthroughs, discoveries, and DIY tips sent six days a week. The entire field of archaeology hinges on what can withstand the test of time. This typically means that most excavations center on hard evidence including structural remains, pottery, weapons, or metalwork. Occasionally, researchers discover something softer that’s been preserved for thousands of years despite the odds. In Switzerland, archaeologists recently identified what may be an especially rare find. While clearing the grounds of an upcoming residential development about 20 miles northeast of Zurich, specialists at the Aargau Cantonal Archaeology service found what they believe is a chunk of charred, 2000-year-old Roman bread .…