The beauty of yerba mate loose leaf is that it can be brewed both hot and cold.The ideal temperature at which Yerba Mate can be brewed hot is somewhere around 80 degree Celsius. This is somewhere off the boil. A common way to understand your mate water is to put it off the stove when fish eyes kind of water droplets start appearing at the bottom of the vessel. This is where your mate water is ready to be poured over the loose leaf. As for the cold or terere brew you can load it with ice. But make sure you wait for around 25/30 seconds before you sip as yerba mate loose leaf may take a bit longer to brew cold.