Q:

What does the phrase "grain and hair of life" mean?

from the Wapshot Chronicle by John Cheever:

For with his maturity, Moses had found in himself a taste for the grain and hair of life.

The context doesn't really help so much in understanding.

A:

The hair and the grain are the two outermost layers of an animal hide. When a hide is tanned the hair is removed, and the grain, the irregular surface, is usually sanded and polished to eliminate imperfections. 
Now take a look at Cheever's use of this as a metaphor in its context; Moses has risen very early in the morning to go fly-fishing:  

He gathered in his line and made another cast, wading so deep in the pool that his crotch got wet, a blessing, he thought, hoping that the cold water would discourage his mind from ever leaving such simple pleasures, for with his maturity Moses had found in himself a taste for the grain and hair of life.  

Moses' taste for the hair and grain of life is a preference for life in its simplest natural state, without being artificially "processed" by socialization.  

