Why does alcohol make us pee so much? – The science behind ‘breaking the seal’

Why is it that on every night out, I spend half the night queueing for the loo? And before that I face the inner turmoil of ‘do I go or hold it in?’ to avoid ‘breaking the seal’, because apparently when you let yourself pee once the floodgates are open and you just can’t stop needing to go. I just had to find out why alcohol has this effect on us, and if the ‘breaking the seal’ is a real thing.

breaking the seal
Alcohol making you pee so much is particularly an issue at a festival with horrible porta-loos that you queue 20 mins for the privilege of using…

Why does alcohol make us need to pee so much?

Drinking makes us need to go so often because it is a diuretic (that’s a fancy word for ‘substance that makes you need to wee a lot’). It has this effect by acting on the pituitary gland, reducing the amount of anti-diuretic hormone (aka Vasopressin) the pituitary gland releases. Normally anti-diuretic hormone would act on the kidneys and make them reabsorb water, so there is less volume of water in your urine – making you produce less pee. But when alcohol reduces the amount of anti-diuretic hormone, the excess water is not reabsorbed by the kidneys, and all that extra liquid ends up increasing the amount of urine we produce when we drink. 

By the way – when we are drunk, so much water gets flushed out of our body that our liver has to grab water from other organs to be able to deal with all the toxins we give it on a night out. This includes water being drawn from the brain, which gives us that all too familiar headache the next day.

Does switching to shots help?

Some friends think that switching from pints or other long drinks to shots will make the need to pee less because the volume of liquid is less. These friends are wrong – the diuretic effect is still just as bad with shots because it’s the alcohol that makes you go more, not the increased volume of liquid you are taking in. 

Does ‘breaking the seal’ make it worse?

As I said before, we all tend to hold it in until we are about to burst because of a common conception that the diuretic effect of alcohol works in a ‘once you pop you just can’t stop’ kind of way, in that once we have that first wee, we then won’t be able to stop. There is actually no evidence for this. It is a lie. What actually happens is that by the time you let yourself pee, enough time would have passed for the diuretic effect of alcohol to kick in. Its has nothing to do with when you decide to go / how long you wait – so just do everyone a favour and next time you drink stop squirming and just go and pee! 

So I have once again cleared up one of life’s great mysteries using science, you may thank me Friday night with a glass of champagne (you will probably find me in the line for the loo…)

Till next time,




Why does champagne pop? – The science of poppin’ bottles

Science of champagne pop

I love a glass of champers, but it’s always a tense moment when I try to open a bottle without causing an inevitable volcanic eruption of bubbles, resulting in an expensive puddle on the floor. Why does champagne have to be such an awkward drink, with it’s big explosion and obnoxious popping sound? It even demands a different shape glass! I just had to find scientific reason why something so good has to be so fussy…

Science of champagne
One simply can not graduate without a full champagne glass

Why does champagne pop?

To understand this you need to know that carbon dioxide is dissolved in the wine, and there is also some carbon dioxide in the air space between the wine and the cork. Before you open the bottle the amount of carbon dioxide gas in the wine and in the air space is balanced out. When you open the bottle, the carbon dioxide is released, this is what makes it pop!

But not all of the energy stored in the bottle is released as sound! You may be one of the unlucky people to have been hit with a flying champagne cork (first word problem). The reason the cork flies is because some of the energy stored in the closed champagne bottle is released as kinetic energy, which gives the cork some air time. If opening a bottle fills you with fear of breaking windows/ someone’s nose, you can change how much the cork flies by changing the temperature of the wine. Research has shown that the warmer the champagne, the bigger the CO2 cloud is released, so the cork flies further. This is because a change in temperature changes how soluble CO2 will be in the champers. A colder wine is a safer wine apparently.

Why so fizzy?

A rush of CO2 is released when we pop a cork, which is why it can erupt into a bubbly mess, but it gets fizzy in the first place from a process called fermentation. Yeast molecules digest sugars found in the grape juice into CO2 and ethanol, and its the CO2 that gives the bubbles and the ethanol that gives the happiness. What is special about champagne compared to other alcoholic beverages is that it ferments twice, the second time inside the bottle. Loads of chemicals help this process along and a different composition of chemicals will alter the taste of the champagne, which is partly why some are delightful and some are not so great.

Why does champagne need a special glass?

As if we didn’t have to be careful enough with this stuff it requires it’s own style of glass, but why? Research has found that the shape of a champagne flute really does affect the taste, with a taller, more narrow glass providing a better flavour. Much more CO2 was present at the top of a narrow champagne flute then at the top of a wider glass. This is important because CO2 bubbles in champagne carry aroma molecules on them up through the liquid and release them when they pop, so more CO2 bubbles reaching the top of the glass will stimulate your sense of smell, and in turn improve the taste.

This effect works even better when the bubbles form from the bottom, centre of the glass so that the gas can carry more aromas and stimulate your nose more. Bubbles will tend to form from where there is an imperfection in the glass, this is why really posh champagne flutes are often purposefully scratched in this place.

Here’s a top tip: pour your champagne at an angle – research has found that this preserves double the amount of CO2 bubbles, which gives us a better smell and therefore taste!


Till next time,