#112 Frozen! Burning! It Even Melts Metal!? The Surprising True Face of Vinegar

Exploring the mystery of "Glacial Acetic Acid" that freezes at 16 degrees.

As the concentration of vinegar approaches 100%, it begins to freeze at a surprisingly high temperature of 16 degrees Celsius. Because it solidifies easily in winter, chemical plants must keep it warm using a method called "tracing," where thin tubes carrying steam are wrapped around the pipes. The episode shares the unique struggles faced on-site, not unlike dealing with frozen water pipes in winter.

We also discuss the unexpected danger that although it is a food product, it is "flammable."

Did you know that 100% pure acetic acid is classified as "hazardous material" under the Fire Service Act? It has the property of catching fire when heated to around 40 degrees, and could potentially ignite from static electricity or sparks. It is surprising to see this sharp, material side of vinegar that we would never imagine from the vinegar we consume daily.

What is this powerful corrosivity that can even dissolve metal?

Although known as a "weak acid," acetic acid shows its teeth to metals like stainless steel when in high concentrations and at high temperatures. The fact that it can erode even sturdy materials under certain conditions highlights the depth of chemistry. There is much more to discuss, so please be sure to listen to the full episode.