The water in my Ratio Four isn't hot enough. 

If the coffee that your Ratio Four is producing is not hot enough, there are a couple of things that we can change in the brew routine and equipment used to maximise the final temperature.

Why we don't use heat plates.

In the design of the Ratio Four, we have made the intentional decision to omit a heat plate. While heat plates help to preserve or even raise the temperature of your brewed coffee in the carafe, the addition of heat also acts as a catalyst to speed up the breakdown of chlorogenic acids in your coffee into quinic acid (the active ingredient in tonic water) and other byproducts that are responsible for the flavors associated with "stale" coffee.

How the Ratio Four heats

The Ratio Four heats water with an aluminum flash heating element capable of bringing water to a boil in seconds. Water then travels through the supply lines and out the shower head, propelled by heat pressure and the internal pump.

After the flash heating step, your brew water begins to lose heat energy as it continues through the brew path, exiting the shower head around 195-205 degrees. Once the water is exposed to the air and ambient room temp, it will continue to lose energy, but the machine is designed to take advantage of this heat loss,  so water hits the coffee bed around 195-200 degrees, which is where most experts, including the SCA, agree proper extraction occurs

How to maximize the temperature in your carafe.

The science:

When hot water comes into contact with a cooler object,  heat energy is absorbed by the cooler object. The amount of heat energy that an object can absorb varies. Items that absorb more heat energy tend to hold onto heat energy and are better for insulation. Items that absorb less heat energy will not absorb as much heat energy, but also will not offer much assistance in maintaining temperature. There are multiple points along the brew path where temperature loss can occur due to heat energy lost to materials.  We can use this information to reduce temperature loss with a couple of adjustments to your routine. 

In practice:

The brew basket: The plastic in the brew basket of the Ratio Four absorbs less heat energy than metal, but pre-heating the basket and pre-wetting the coffee filter can be very helpful to minimize temperature loss in the brew-bed. The importance of this step only increases when you replace the default dripper with a metal or ceramic one. 

The carafe: The carafe is the other piece of the puzzle for temperature maximization. The glass carafe that comes standard with the Ratio Four is designed for quick service; preheat and serve immediately for best results.

Preheating becomes even more important when a thermal carafe is paired with your Ratio Four.  While the metal in a thermal carafe will absorb more heat if it is not preheated, when properly heated, it can insulate your coffee and keep it hot for hours, with no additional heating and little to no "stale" flavor.

Conclusion

Experts agree that removing a heater from your coffee setup ensures that your coffee tastes better longer. With a little bit of preheating, you can make sure it stays hotter longer, as well.