Proof Spirit Introduction

Proof spirit

Introduction: Distillation of ethyl alcohol (C 2H5OH) produces Spirit. Spirit is used as a consumable alcoholic beverage. Pharmaceutical spirit is an alcoholic or hydro-alcoholic solution containing volatile ingredients. The strength of the spirit is measured by the amount of ethanol present in the spirit. Normally, the strength of the spirit is measured in alcohol by volume (ABV).

The following points differentiate spirit from alcohol.

1. Spirits are produced by the distillation. Alcohol is produced by the fermentation.

2. Spirits are a group of consumable alcoholic beverages. All alcohols are not consumable.

3. Spirits mainly contain ethanol. Alcohol may be methanol, ethanol, butanol, etc.

The term “proof” has a historical origin in alcoholic preparations. In the 18th century alcoholic content of spirit was tested by using gunpowder. The spirit that contains enough alcohol ignites the gunpowder. The spirit that ignited gunpowder was called the proof spirit.

Nowadays, the term proof spirit is mainly used for regulatory purposes. It helps the Government, producers, and consumers to understand the alcoholic content in alcoholic beverages.

Nowadays, “proof spirit” is expressed by the amount of alcohol by volume (ABV). A mixture of pure alcohol (absolute alcohol) and water having a specific gravity of 0.91976 is a proof spirit. “Spirit with specific gravity 0.91976 will have 57.1% v/v or 49.28 w/w absolute alcohol and is called proof spirit”.

• · In the USA, a spirit containing 50% absolute alcohol by volume (ABV) or 42.49% absolute alcohol by weight is considered as proof spirit. (That is 50%v/v or 42.49% w/w absolute alcohol)

• · In India and Britain, spirit containing 57.1% absolute alcohol by volume or 49.28% absolute alcohol by weight is considered as proof spirit. (That is 57.1% v/v or 49.28% w/w absolute alcohol).

Definition:

Proof spirit: “Proof spirit contains 50% v/v absolute alcohol as per USA norms or 57.1% v/v as per Indian and Great Britain norms”.

The strength of alcohol (ethyl alcohol) in spirit is expressed by the terms proof spirit, proof strength, or proof gallon.

• · Proof strength: “Proof strength is twice of the percentage of alcoholic strength in spirit”. 100-proof spirit means it contains 50%v/v of absolute alcohol. 90-proof spirit means it contains 45%v/v of absolute alcohol. Conversely, 50% v/v spirit means 100 proof spirit. 90% v/v spirit means 180 proof spirit.

          Proof spirit = % Strength of absolute alcohol X 2. This formula is as per USA norms

           Proof spirit = % Strength of absolute alcohol X 1.7513. This formula is as per Britain norms.

• · Overproof: “Spirit containing absolute alcohol more than absolute alcohol in proof spirit (100 proof spirit) is called over proof.”

• · Under proof: “Spirit containing absolute alcohol less than absolute alcohol in proof spirit (100 proof spirit) is called under proof or below proof”.

• · Gallon proof: Gallon proof is not a standard term to measure the strength or content of alcohol in spirit. It may used in reference to large volumes of spirit measured in gallons.

Q. Converts 80% v/v alcohol into proof spirit opting Indian norms.

Since 57.1% v/v alcohol means 100 volumes of proof spirit

Thus, 1 volume of 57.1% v/v alcohol = 100/57.1 proof spirit = 1.753 proof spirit.

It means 1% v/v alcohol = 1.753 proof spirit.

Thus 1 volume of 80% v/v alcohol = 1.753 X 80 =140.104 proof spirit.

Q. Converts 65% v/v alcohol and 40% volume by volume alcohol into proof spirit and proof strength using Great Britain norms.

As per Great Britain norms, 1% v/v alcohol = 1.753 proof spirit.

Thus, 65% v/v alcohol = 65 X 1.753 proof spirit = 113.75 proof spirit.

Thus, Proof strength = 113.75 – 100 = 13.75

40%v/v alcohol = 40 X 1.753 proof spirit = 70.12 proof spirit.