What does it mean when a liquor bottle says 40% ALC by vol (80 proof) ?

As we understand alcohol is lighter than water in Science studies. 40% of ALC means 100% of liquid 40% is alcohol. The higher the percentage is , the stronger the liquor is. Usually beer only have less than 10% of ALC ( except for some strong brew ) .

In early distillation of liquor, the product would be mixed with black gunpowder then a flame applied. When the mixture would burn, this was considered as "proof" of the alcohol content of the liquor. When chemical analysis was later developed, it was determined that this was a 50% alcohol content by volume, that is one half of the liquid was alcohol. Hence, the "proof" value is twice the percentage of actual alcohol in the liquor. Grain alcohol ("everclear" is a popular name) is about 160 proof, or 80% alcohol, a very potent potable.

Old historical stuff mixed with chemistry. People drink liquor for its alcohol content, and they want full buzz for their dollar. So how do you measure the 'proof' or percentage of alcohol content of what's essentially an alcohol / water mix? The classic way is to drip some of the mixture in question into the old campfire. If the mixture is 50% alcohol or more, the fire will flare up. If it's less, then it won't. So a minimal mixture of alcohol and water that'll cause a flare-up was termed '100 proof.' If you cut this mixture half-and-half with water, you'll get 50 proof, which is 25% alcohol.

There are ways of cheating in this process, none of which you'd want to try, like mixing in flammables like lighter fluid to increase the flame.

The proof system for stating alcohol content is a complicated, non-linear system based on an old method of determining alcohol content by testing how much booze you can pour on a pile of gunpowder and still ignite it. It was used by customs officers working out the excise duty payable on the booze, which depended on the alcohol content. Non-linear means that100 proof isn't exactly twice as strong as 50 proof. Alcohol hasn't got the same density as water, so if you add 40 mls. of alcohol to 60 mls. of water, you get a different strength from adding 40 grams of alcohol to 60 grams of water. So when you state the percentage of alcohol, you need to state whether it's by weight or volume.

It means that 40% of the product is pure ethyl alcohol. Proof is a number double that of the alcohol percentage. Ethyl alcohol is the active ingredient i.e. the compound that makes you intoxicated.

There are 190 proof (95% alcohol) products which must be handled with great care as they can kill you or catch fire. 100% alcohol would volatilize almost instantly so some water is needed to keep it in a liquid state.

alcohol content of the liqour. the higher the stronger the better lol ♥

its 40 % alcohol

It means you drink too much lady.

means youre going to have a good night lol