Field and test information
Despite an extension for the long-term test, October and November weather in my region has been mostly mild, so I have not been able to add to my experience with the Granite Gear Winterizer (which was, however, fairly extensive during the Field Report period). Over the total test period, the Winterizer was used for around ten days on a mix of day hikes and overnight backpacking trips in the Catskill and Adirondack Mountains of New York State, at elevations to 4500 ft (1372 m). Much of the hiking involved off-trail excursions over tough terrain i.e. "bushwhacks," and included a number of the more difficult Catskill peaks. Minimum pack load was 12 lb (5.4 kg) or so for day hikes and up to 28 lb (11.3 kg) for backpacks. The lowest temperatures experienced during the testing period were at night, down to approximately -15 F (-26 C).
Product Use and Performance
The Winterizer (courtesy Granite Gear)
The Winterizer is, as previously noted, a useful tool for winter day hikes, during which it generally prevents ice from forming in the tube of my hydration system. To some extent its usefulness depends on conditions. It is less practical at very cold temperatures, approximately 0 F (-18 C) and below. Some care is necessary in use, and in transporting the pack containing the hydration system. In winter conditions, the Winterizer will not prevent the tube from freezing up if the unit is stored in an unheated car trunk for any protracted period, en route to a hike. If the hydration tube within the Winterizer does indeed freeze, the insulation makes it difficult to thaw it out in the field, unless just the mouthpiece is affected.
Removing the insulation for the purpose of defrosting (which can be done using a chemical heating pad, or warm water on a stove) is not that easy, and is a very frustrating exercise in the cold. It involves removing the hose from the mounting on the cap that attaches it to the reservoir (or alternatively, removing the mouthpiece), pulling the hose from the Winterizer sleeve, defrosting as noted above, and then replacing the hose in the sleeve (and reattaching the hose or mouthpiece). As noted in the Initial Report, inserting the hose in the Winterizer is tricky at the best of times.
It is for these reasons that I have reservations regarding the use of the Winterizer in winter backpacking. By exercising care in gently blowing as much water as possible out of the mouthpiece and hydration tube, and by immediately detaching it from the reservoir when stationary for any period (using a standard cap to close off the reservoir and expelling all water from the tube), it is possible to keep the system operational. The problem is that if these precautions are overlooked, the system will inevitably ice up. It's up to the user to weigh whether the effort involved is worth the benefit. I do tend to under-hydrate in winter (and frequently pay for it with leg cramps once I'm bedded down for the night). For this reason, I will continue to try to use the system this coming winter, but I must report that my experience last winter was not encouraging. It may be that with practice I'll have more success. I may amend my report in due course to this effect.
I have not had any problems to date with keeping the Winterizer clean. I've not seen any tendency for mold to grow on it, and it is still mold- and must-free. The use of a heating pad in the mouthpiece pocket does seem to work in keeping the mouthpiece free from ice. I was not pleased with the clip on the mouthpiece pocket that's designed to keep it attached to the pack. This does come loose from pack straps all too easily. I'd prefer to see a clip that locks in place on the pack harness. What's supplied doesn't have enough tension to do the job well.
On another design note, I wish the Winterizer was slightly longer. It is a foot (0.3 m) shorter than my Platypus hydration tube. While that uninsulated portion is protected in part by being in my pack, it is the section that is most likely to contain water, and I don't think that the pack contents are effective as insulators. There are likely to be too many gaps where the tube is exposed to the ambient air. Indeed, if I'm using a 3 L (3 qt) Big Zip in the vertical orientation, basic physical principles indicate that water is going to be present in the uninsulated portion to the same height as it stands in the reservoir. At the outset of a trip, this may mean that the entire uninsulated section will be full. Unless I have pre-heated the water (not always possible), my experience is that this is the portion of the tube where freezing is most likely to occur on very cold days. Ideally, I'd like to see the insulation extend all the way down to the outlet of the reservoir.
Summary
I had posed a series of questions that I'd been examining in this test in the Initial Report. I've been able to answer most of these to my satisfaction. The Winterizer is a useful addition to the pack for winter day hikes, especially when the weather is not of Arctic intensity. The insulation does help prevent freezing in the hydration tube, and the provision of a pocket to contain a chemical warmer to prevent mouthpiece icing is a definite plus.
The Winterizer works with both Platypus and CamelBak systems (I have not tested others). It's durable and (so far) odor free. I've experimentally soaked the Winterizer in an enzyme cleaner (Mirazyme), and no harm came to it (nor would I expect any problems), and this will be my solution, should an odor problem arise. I'm not especially pleased by the sternum strap clip, which does not hold at all well.
I've found no better way than that described in the Initial Report for inserting the tube, and I really feel that a zip running along the tube would make the Winterizer far easier to use, and may in fact prove essential for backpacking use. Still, I do think the Winterizer addresses a real need, and despite these various concerns I recommend its use for winter day hikes. I have reservations about its use for backpacking, although it may be that with still more practice I'll be able to come up with a truly effective strategy.
I'd love to see the following improvements:
1. A full length zip for easy removal.
2. Insulation (perhaps as an adhesive foam add-on) to cover the section of the hydration tube that's within the pack.
3. A truly effective sternum clip.
I thank BackpackGearTest and Granite Gear for permitting me to participate in this test.
