Hario’s factory remains the only heatproof glass factory in Japan. It is still in the same place that the company operated from back in the 1950s.
Thanks to the combination of materials they’ve concocted, Hario’s heatproof glass has special qualities. For example, Hario glass is microwave safe and it also doesn’t allow for the transfer of odours. This is perfect for coffee brewing so what you produce is always fresh.