How to Stretch Leather Boots Five Methods:Freezing Heating Rubbing Alcohol Commercial Stretching Spray Boot Stretcher If the new pair of leather boots you pined for and eventually bought are uncomfortably tight on your feet, you can stretch the leather out for a more customized fit. Likewise, if your trustworthy pair of leather hiking boots has shrunk over time, you can stretch them out to return them to their original condition. There are a few different methods you can use the stretch your leather boots at home. Method 1 of 5: Freezing 1. 1 Fill a resealable plastic bag with water. Fill roughly one-third to one-half of the bag with water. Squeeze out as much air as possible before sealing completely.[1] • To remove the air, seal most of the bag, leaving only a small gap open in one corner. Gently squeeze the portion of the bag without water in it until the plastic sides come together. When you have brought the sides together as closely as possible without spilling water, seal the remaining gap. • Use plastic bags marked as "freezer bags" to reduce the risk of breaking the bag inside the freezer. • Choose the best size for your boot. If the toe or heel needs to be stretched, a quart (liter) size bag should suffice. If the entire foot portion or calf portion of the boot needs to be stretched, choose a gallon (4 L) size bag.