When you expect a piping cup of coffee from your brewer but get something a lot cooler it may cause you to scratch your head, and likely think the brewer is malfunctioning. But before you are convinced it's the brewer, we have a couple things to consider that may be a big game changer in the temperature in your coffee.
First off, for the coffee brewers such as Technivorm and Ratio, water moves through these brewers only by the pressure caused by boiling water in the heating element. There is no pump that moves the cold water from the reservoir into the heating element, and then through the tubing to the showerhead, unless it is already at a boil. This reduces the likelihood that the coffee brewer is delivering cold water over your coffee grounds, because it couldn't physically get there unless there was steam pressure caused by boiling water to push the water through. Additionally, the genius in this design is that while you want the water to be hot, you don't actually want boiling water to hit your bed of fresh ground coffee. So as the water flows toward the showerhead it cools slightly, stabilizing from 197- 200º which is the optimal brew temp for coffee.
Now, with that in mind, there are some other factors involved that will affect the temperature of your coffee. With the Technivorm and the Ratio Eight, there are a lot of glass and metal components that sitting overnight can get quite cold. Think about it this way: if you have a cold cup and pour something warm into it, it is going to lose some heat. The exact same thing happens with your coffee brewer and a cold carafe (and other parts of the coffee brewer). That is why if your finished brew temperature is too low, preheating the carafe will help keep more heat in your coffee. In fact, it can make the difference of 10-15 degrees!
On The Ratio Eight, the hand blown glass carafe incorporates the dripper and holding vessel in one unit. This substantial mass can draw a lot of heat out of the coffee, especially when the room temperature is colder or if the carafe becomes chilled while transferring water to the tank. You can preheat the carafe with hot water from your sink, a kettle, or by running a brew cycle of any size without coffee. Alternately, you could fill the tank beyond your intended batch size and stop the brew cycle when the tank reaches the desired level by pressing the start button. If you run more than intended, just top up the tank as needed. These techniques can also be used to rinse the paper filter and preheat at the same time. These tricks can be used on either the Ratio Eight or the Technivorm.
Try this out, and let us know what you think!