Avoiding Frozen Waterbottles

[Chris Helwig]

A few people had problems with their bottles freezing at Good Friday. I apologize for not posting this earlier, but here is some tips for future cold rides or races to avoid frozen bottles.

Option 1: Double Strenth Gatorade. Use two full scoops of Gatorade (I find the orange tastes best). It is syrupy, but will not freeze unless it is close to -15. Even then it turns into a slushy and you can still usually get some out. I think it is the low grade road salt in the gatorade that keeps it from freezing, especially when it is double strength.

Option 2: Add table salt to Gatorade or other sports drink. Add a full spoon full on regular table salt to any sports drink and that should also work.

Option 3 : Disclaimer, I have not tried this myself but I hear it works well and that the winner of the 1/2 race did this. Add a tiny bit of vodka to your bottle. Apparently it totally prevents freezing. Maybe if someone has tried this they can post how much you should put in. Some guys swear by this apparently.

[Chuck Norris]

Vodka! Why the Hell didn't I think of that? Gives me a few ideas. Not sure how crushed fruit and a paper umbrella would work in a waterbottle, but I'll try anything.

[Graydon]

Not that I doubt that anyone put vodka in their bottle on friday, but I am doubtful that it actually is the reason their bottle did or did not freeze:

If it was -10.0 degrees Celsius with the windchill at Good Friday, the freezing point depression constant (-1.86) tells us we need a vodka/water ratio 5.38 moles vodka per kg water.

For a 500 mL water bottle, you'd need to add 2.69 moles of ethanol. 1 mol of ethanol is ~ 46g, thus 2.69 moles is ~123 g.

100 proof vodka is 50% ethanol, 50% water, therefore you'd need to add at least 250 ml (1 cup) of vodka to your bottle. Most people raced with 2 bottles - if you could drink that much vodka and win a 1/2 race, I think freezing bottles is the least of your problems.

[Chris Helwig]

Since it appears the Vodka rumours have been myth busted, is there a salt ratio or guideline to how much salt needs to be in a bottle? I have ridden with double strength Gatorade up to at least -8 celcius, and -10 or -11 with the windchill and still been able to drink. A few crazy times I went out colder than that it would tend to turn into a "slushy" but you could still get some liquid out.

[Graydon]

I suspect the "magic" with Gatorade has to do with the trans-fat they add to it (yes, it's in there, read the ingredients) as the anti-clumping agent. I suspect it is hydrophobic and somehow prevents the formation of ice crystals which would initiate the freezing process. Most legit sports drinks don't add oils or trans fats to their product.

I don't think you will find any tolerable amount of salt or sports drink to add to a solution to keep it from freezing. Any foreign substance added to water will cause the freezing point drop, but it has to be a really strong solution to have a significant effect. For every mole of foreign particles dissolved in a kilogram of water, the freezing point goes down by roughly 1.8°C. For example, if you added 5g of salt to your water bottle, that would lower the freezing temp to only about -0.5 degrees C. That's a lot of salt, and not much benefit against solidfying. Ocean-water freezes at about -2 degrees C, and you definitely don't want to drink that much salt.

Sugars would be even less effective, because they have a higher molecular weight, and it would require about 340g of sugar (sucrose, principle ingredient in gatorade) to lower the freezing point the same amount as 28g of salt.

[Chris Helwig]

Looks like the trans fat riddled Gatorade is the best bet to avoid freezing bottles. Double strength of the powder seems most effective, I guess the more trans fat the better :eek: Even though the Gatorade is not a very good sports drink in general, using it on very cold days is better than your bottle freezing up and not being able to drink at all.