Zoku claims its insulation can cool the liquid down to iced temperature in less than five minutes. Compared to cold-brewing your own batch, or just waiting for a hot mug to cool down, the convenience provided by a purpose-engineered liner is worth the $30 price.  Search “richard sapper espresso coffee maker” from This Mug Makes Iced Coffee in Under 5 Minutes

Search “richard sapper espresso coffee maker”

Zoku claims its insulation can cool the liquid down to iced temperature in less than five minutes. Compared to cold-brewing your own batch, or just waiting for a hot mug to cool down, the convenience provided by a purpose-engineered liner is worth the $30 price.