Includes 4 ice packs and an insulated mailer to help keep your liquid yeast cold during transit. The Insulated Mailer option is a great way to extend the length of time your ice remains cool!  These special envelopes contain self expanding foam, which creates a form-fitting container that protects and insulates liquid yeast.  This upgrade includes the Insulating Envelope and 4 Ice Packs.

This option fits a number of yeast vials, pouches, or cans, and is made from thick foam insulation.  Because different yeast take up different space, each producer will fit a different quantity in this mailer.  See the chart below for what quantity of what yeast will fit inside.