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Reviews > Hydration Systems > Bottles > Forty Below Bottle Boot > Owner Review by Michael Pearl


May 01, 2017


NAME: Mike Pearl
EMAIL: mikepearl36ATyahooDOTcom
AGE: 43
LOCATION: Hanover, New Hampshire, USA
HEIGHT: 5' 9" (1.75 m)
WEIGHT: 155 lb (70.30 kg)

I have a great appreciation for the outdoors and get out at every opportunity. I am a three-season, learning to be a four-season backpacker and year-round hiker. Currently, my trips are two to three days long as well as an annual week-long trip. I utilize the abundant trail shelters in my locale and pack a backup tarp-tent. I like to cover big distances while still taking in the views. I have lightweight leanings but function and reliability are the priority. I mostly travel woodland mountain terrain but enjoy hiking beautiful trails anywhere.


The Bottle Boot

The Forty Below Bottle Boot is an insulating water bottle holder. It is used to prevent fluids from freezing during outdoor winter activity. It is made of neoprene much like a wetsuit used for diving. The purpose is the same: to keep what is inside the neoprene warmer than what is outside the neoprene.

Manufacturer: Forty Below Ltd
Year of Manufacture: 2014
Manufacturer's Website:
MSRP: US$19.95

Made in: USA
Material: Neoprene

Listed Weight: 4.5 oz (126 g)
Measured Weight: 4.6 oz (131 g)

Sizes Available: 16 oz (0.5 L), 24 oz (0.71 L), 32 oz (1 L), 51 oz (1.5 L) and 48 oz (1.42 L)
Size Reviewed: 32 oz (1 L)

Colors Available: Red, Royal Blue, Black, Yellow, Pink, Green and Purple
Color Reviewed: Black

1/4 in (6.5 mm) thick closed cell neoprene foam insulation
Velcro front closure
Webbing belt loop
Fits bottles up to 3-3/4 in (9.5 cm) in diameter and 8-1/2 in (21.6 cm) tall IMAGE 2


The Bottle

Manufacturer: Hunersdorf
Year of Manufacture: 2014
Purchased at:
MSRP: US$10.00

Made in: Germany
Material: PE (Polyethylene)

Listed Weight: 4.8 oz (135 g)
Measured Weight: 4.2 oz (120 g)

Sizes Available: 32 oz (1 L), 51 oz (1.5 L)
Size Reviewed: 32 oz (1 L)
Dimensions Listed: 3-3/4 in (9.5 cm) diameter by 8-1/8 in (21 cm) height

Colors Available: Transparent bottle with yellow cap

Temperature Rating: -40 F (-40 C)

Forty Below does not manufacture the Bottle but sells it on their website. In an internet search I was unable to find a company website for Hunersdorf, only other sites selling their bottles.

The Hunersdorf Bottle is a water bottle made of somewhat soft, semi rigid squeezable plastic. The cap is slightly oversized requiring less dexterity to open and close.


I have used the Forty Below Bottle Boot and Hunersdorf Bottle for three winter seasons. The Boot and the Bottle have always been used together. The only exception is when snuggling with the cozy, warm Bottle in my sleeping bag. They have been used in temperatures ranging from 40 to -15 F (4 to -26 C) on numerous day hikes and at least ten overnight backpacks. I have carried room temperature to boiling water as well as tea with honey in the Bottle.

IMAGE 3 IMAGE 4 The Bottle Boot has cushiony feel and is stretchy. All the seams are even and neatly sewn. After two seasons of use there are no frayed stitches or signs of wear. The Velcro closure is easy to open and close even when wearing gloves or mittens. This is a huge plus when it's very cold and a quick sip of water is needed. I usually clip a carabiner on my hip belt or shoulder strap, then clip the belt loop of the Bottle Boot to the carabiner. This makes for quick and easy access preventing prolonged breaks and loss of precious warmth. When the temperature is just cold I will slip the Bottle out of the Boot to drink. The Boot being stretchy the Bottle slips in and out easily. When it's very cold I detach the Boot from the carabiner to preserve the water temperature as much as possible. Only on the coldest day of -15 F (-26 C) did ice build up in the Bottle. On these very cold days I carried the Boot and Bottle in my pack. I would tuck the Boot in around an extra jacket or hat: this would act to further insulate the liquid in the Bottle. This occurred after several hours of hiking and the Bottle was halfway empty. The ice was a thin layer at the top of the water line. The ice was easily broken up with a squeeze of the Bottle and the remaining water drinkable. On a hike at a temperature of 0 F (-18 C) and about six hours of hiking I didn't have any ice in the Bottle. This was after filling the Bottle with near boiling water and driving an hour to the trail. The last of the water on the trail was not warm but it was not frozen either.
The Hunersdorf Bottle has a bulky cap with raised ridges on the sides. This along with coarse threads makes getting the cap on and off very easy even in gloves or bulky mittens. The bottle itself is not a rigid, hard plastic but rather flexible or squeezable. Being squeezable is beneficial if the fluid in the Bottle freezes. If not frozen solid the Bottle can be squeezed making it easier to break up any ice formed. Sometimes I find it difficult to consume enough water when it's cold. When boiling water I think of making tea. So for one hike I put tea with honey in the Bottle. The aroma alone encouraged me to drink more while hiking. The only minor downside to putting "flavor" in the Bottle was that it retained a faint hint of tea. This is just in smell and when filled with plain water does not affect the taste.


The Forty Below Bottle Boot and Hunersdorf Bottle work as a great team. Together they help to maintain a drinkable supply of fluids in winter conditions. I have been nothing but pleased with their performance during every use. Whenever I head outdoors in freezing temperatures I warm some water and fill my Hunersdorf Bottle wrapped in the Forty Below Bottle Boot.IMAGE 6


Boot hook-and-loop easy to open and close wearing gloves and mittens
Boot helps keeps liquids from freezing
Boot easy to attach to belt or pack strap
Able to remove and replace Bottle cap with gloves or mittens
Can drink from Bottle in or out of boot


Not a thing
While not a negative to me, the Bottle has retained the aroma of tea.

This report was created with the Report Writer Version 1.5 Copyright 2017. All rights reserved.

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Reviews > Hydration Systems > Bottles > Forty Below Bottle Boot > Owner Review by Michael Pearl

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