Glass: From Liquid to Solid
Glass is magical stuff. When you look at a glass object, you would never guess that it was once a hot, flowing liquid that could be inflated or molded or swirled into almost any shape. What is your favorite thing made of glass?
To create glass you must melt sand, soda (sodium carbonate), and calcium from limestone or chalk at an extremely high temperature. Have you ever seen glass that has a greenish tint? Green glass is made with sand that contains traces of iron.
An average person in the 1500s in northern Europe would have used the kind of glass shown in this picture at mealtime. Why do you think there are big bumps, called prunts, on the outside? Maybe these blobs helped people to grip the glass with greasy hands, or maybe they just made the glass feel good to hold and were used for decoration.
Many of the glasses that have survived from the 1500s were meant for drinking beer. People drank a lot of beer in Northern Europe at that time because it was very difficult to get pure, clean drinking water. Tea and coffee were luxuries. Beer was one of the safest drinks available. It had to be boiled as part of the brewing process, killing any bacteria in the water. There was a low-alcohol beer to quench thirst and a sweet and spicy version that was served warm at breakfast.