flat lager

[markjohnson]

when pouring a pint it goes flat before putting it on the bar, why?

[adydb]

You forgot a glass?......

 

Serious though, if its in a pub its a simple case of their gas (Carbon Dioxide) isn't pumping into the beer.  

[Flurfl]

Just doesn't have much gas dissolved in it I would expect..

[rinkytink]

 

Another possible reason for flat / flat looking beer is incorrect detergent or rinse aid levels in your glass washer. If these are still present on the glass when the beer is poured it can have a great impact on quality.

[buchanan]

Could also be down to being badly poured - you need to hold a pint glass almost horizontally when you begin to pour then lovingly, and steadily bring up, finishing with the glass upright.  Begining to pour with the glass already upright will knock the gas out of the liquid.