Tag Archives: experiments

To squeeze or not to squeeze the soda bottle

I’m the first to admit that sometimes I can be a little nerdy.  Take the subject of this blog post for example.  I have long wondered who has it right.  The person who just closes the soda bottle for storage or the person who squeezes it tight before closing.  Before you say “Of course the squeezing is better.  It gives the CO2 less space to escape into.”,  think about the fact that the bottle is trying to return to it’s original shape, thus potentially pulling the CO2 out of the liquid via a vacuum effect (told ya I was a little nerdy).

Soooo, I performed a little experiment to investigate just who is right.

Question: Should you squeeze the soda bottle to prevent CO2 from escaping the liquid?

Hypothesis: The smaller the volume of air available for the CO2 to escape into, the better.

The Experiment:

I chose root beer for my experiment because it tends to have the largest amount of bubbles (head) when poured which makes it easy to see how much CO2 is left.

I started off by carefully pouring 1 cup of root beer out of two separate bottles into measuring cups.  You can see in this photo how I closed the two bottles.  One closed with no modification, the second squeezed until the soda was at the top of the bottle and sealed.

I then poured the soda into a glass with 2 ice cubes (to promote bubble formation) from a height of 2 inches over the glass.  Then I measured the head created in the glass.  Finally, I tasted the soda to see how “bubbly” it tasted**.  I repeated this approximately every 12 hours until the soda was gone.  
1st Opening:
Both – 1 3/4 inch head. Very bubbly tasting.
12 Hours:
No Squeeze – 1 inch head. Very bubbly tasting.
Squeeze* – 1 1/2 inch head.  Very bubbly tasting.
*Interesting note: The bottle had unsqueezed itself a bit over the time period even though the top was firmly closed.  Maybe my CO2 extraction by vacuum theory has some merit.
24 Hours:
No Squeeze – 3/4 inch head. Slightly less bubbly tasting.
Squeeze – 1 1/8 inch head. Slightly more bubbly tasting then no squeeze.
36 Hours:
No Squeeze – 1/2 inch head. Not very bubbly tasting anymore.
Squeeze – 1 inch head. Slightly bubbly tasting.
48 hours:
No Squeeze – 1/8 inch head. Almost no bubbly taste.
Squeeze – 1/2 inch head. Slightly bubblier tasting then no squeeze.
60 Hours:
No Squeeze – Almost no visible bubbles. Very flat tasting.
Squeeze – 1/8 inch head.  Only slight bubble taste.


The Bottom Line:
The carbonation defiantly lasted longer in the soda that I squeezed before closing both in taste and looks.  It would be my recommendation to squeeze the heck out of the bottle each time to increase the life of your soda.  That being said, either way you do it, once you hit the two day mark neither method was able to preserve enough CO2 to keep the drink very bubbly tasting so drink up!

**Yes, I know that “bubbles” can not be tasted but you know what I mean.  The fizzy feeling on your tongue you get from drinking carbonated drinks.


Filed under Engineering