If you're like most people, you've been taking a lot of hot coffee out of the fridge lately. Maybe it's because you've been drinking a lot more coffee since the holidays and after the return to work. Or maybe it's just a way to beat back the cold weather by keeping your drink warmer longer. Regardless, I bet at some point after putting your cup of java in the fridge, you started wondering if it was safe to keep doing that or if there was some risk of breakage involved. Well, as long as you're using a tempered glass pot (which is what most coffee makers are), then there's no reason to worry about any kind of disaster happening when taking hot liquid out of cool temperatures—it won't break!
The glass pots that come with the packs are made of borosilicate glass (also known as tempered glass), which has a low coefficient of expansion. That means it can handle different rates of expansion and therefore won't shatter if you put it in the fridge for too long.
If you don't want to chance putting your hot coffee pot in your fridge, wait until it cools down and then put a lid on top. That way, when the temperature changes, there's no pressure on the pot from inside or out—and nothing will break!
Borosilicate has high mechanical strength, good thermal shock resistance and excellent chemical resistance to alkalis and acids. In addition to laboratory equipment, it's also used for the manufacture of glass-ceramic cookware.
The answer to this question is a resounding YES! Borosilicate glass has a low coefficient of expansion, which means it can handle different rates of expansion. This is why borosilicate pots are often used in the kitchen and elsewhere—they can survive extreme temperature changes without breaking.
Because of its ability to withstand drastic temperature fluctuations, borosilicate glass will be just fine if you put it in your fridge or freezer for an extended period of time. This includes both glass cups and coffee mugs (which are made from the same type of material). However, it's not advisable to put hot liquids directly into these containers if they're already full because there may not be enough room for them to expand properly before hitting the lid.
In other words, it's not like one side of the glass is expanding at a different rate than another side because it's tempered. Theoretically speaking, if you were to put hot coffee in your fridge overnight and then drink from the same cup in the morning, there is no reason to believe that it won't break when cold liquid touches its surface.
Tempered glass has a low coefficient of expansion and can handle different rates of expansion, so when you take it from a very hot temperature to a much cooler one (like putting hot coffee in your fridge), there's no stress on the material that might cause it to shatter like regular window glass would do. Tempered glass is also used in car windows and safety glasses because they can withstand sudden changes in temperature without breaking or getting damaged.
If you have a tempered cookware set, like Pyrex casserole dishes or mugs with lids that come together as one piece, then these products are safe for use when storing food items such as soups or oatmeal overnight after cooking them on the stovetop.
Tempered glass is a great material for pots and pans because it can handle different rates of expansion. If you put hot coffee in the fridge, it won't break your pot because the tempered glass has been hardened at high temperatures to make it more resistant to deformity when subjected to sudden changes in temperature.