Before thermometers were invented, brewers would dip a thumb or
finger into the mix to find the right temperature for adding
yeast.  Too cold, and the yeast wouldn't grow.  Too hot, and the
yeast would die.  This thumb in the beer is where we get the
phrase "rule of thumb".

In English pubs, ale is ordered by pints and quarts.  so in old
England, when customers got unruly, the bartender would yell at
them to mind their own pints and quarts and settle down.  It's
where we get the phrase "mind your P's and Q's".

Beer was the reason the Pilgrims landed at Plymouth Rock.  It's
clear from the Mayflower's log that the crew didn't want to waste
beer looking for a better site.  The log goes on to state that
the passengers "were rushed ashore and made to drink water so that
the seamen would have  more beer".

After consuming a bucket or two of vibrant brew they called aul,
or ale, the Vikings would head fearlessly into battle often
without armor or even shirts.  In fact, the term "berserk" means
"bare shirt" in Norse, and eventually took on the meaning of
their wild battles.

In 1740 Admiral Vernon of the British fleet decided to water down
the navy's rum.  Needless to say, the sailors weren't too pleased
and called Admiral Vernon, Old Grog, after the stiff wool grog ram
coats he wore.  The term "grog" soon began to mean the watered
down drink itself.  When you were drunk on this grog, you were
"groggy", a word still in use today.

Many years ago in England, pub frequenters had a whistle baked
into the rim or handle of their ceramic cups.  when they needed a
refill, they used the whistle to get some service.  "Wet your
whistle", is the phrase inspired by this practice.