It's our pleasure to introduce you to Hearth and our Yerba Mate-based, sustainable energy drinks. We're sustainable in both senses of the word; Yerba Mate comes from the naturally caffeinated leaves of a native species of holly tree found deep in the South American rainforest, whilst the energy boost it provides is far more sustainable than traditional energy drinks, which often give you a massive high followed by a sharp crash.Not only is Hearth from the Earth, it has Heart too. Our Passion Fruit and Lemon & Hibiscus flavours come from real fruit juice, rather than sweeteners or a zero calorie chemical mix designed to replicate real flavour.