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A video designed for bar tenders gives away an industry secret - how to tell whether or not your beer glass has been properly cleaned.
The video, made by beer producers MillerCoors explains the difference between clean and 'beer clean'.
Essentially, detergent residues can mess around with the taste of a beer that otherwise has been meticulous brewed, transported, and stored in order to protect the flavour.
The secret to telling if detergent, oil, or other residues are on the glass (and it's not 'beer clear') is by looking for bubbles that cling to the side, or the form head goes down rapidly.
Picture: Benneta Bar Gears/YouTube screengrab
The video explains that the way to check is by wetting the glass and shaking some salt into it.
If the salt coats the inside of the glass evenly all over, your glass is 'beer clean'. If not, there are still oily or greasy deposits which will attract more salt.
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