Expert: Spencer W Thomas - 3/9/2007

Question
Does a tapped keg have to stay cold? The keg with a hand pump?

Answer
Yes.  Once you have tapped a keg with a hand pump, you are pumping in microbes (bacteria and fungi) from the air with each pump.  These will eventually spoil the beer, whether it's kept cold or not, but keeping it cold will slow down the spoilage significantly.

Spoiled beer is not hazardous to drink, but it won't taste very good.  It might get sour (most likely), or develop plastic-like or smoky flavors.

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