Handling is only part of the difference. Uncirculated coins, like those found in the annual mint sets, are indeed minted separately from the regular business strikes. The circulation sets are built with coins minted from the normal business run.
The part about satin finish no longer applies, but the rest of it is certainly true (slightly higher coining force, early strikes from dies, special cleaning after stamping, and special packaging).
Quote:
uncirculated
The term "uncirculated" may have three different meanings when applied to a coin.
First, it can refer to the particular manufacturing process by which a coin is made.
Second, it can be used as a grade when referring to a coin's degree of preservation and quality of the strike.
Or third, "uncirculated" can point to the fact that a coin has not been used in everyday commerce.
At the United States Mint, we use the term uncirculated when referring to the special coining process used to make the coin, which gives it a satin finish. Uncirculated coins are manufactured using the same process as circulating coins, but with quality enhancements such as slightly higher coining force, early strikes from dies, special cleaning after stamping, and special packaging. Uncirculated coins may vary to some degree because of blemishes, toning, or slight imperfections.
http://www.usmint.gov/about_the_min...uncirculateduncirculated
The term "uncirculated" may have three different meanings when applied to a coin.
At the United States Mint, we use the term uncirculated when referring to the special coining process used to make the coin, which gives it a satin finish. Uncirculated coins are manufactured using the same process as circulating coins, but with quality enhancements such as slightly higher coining force, early strikes from dies, special cleaning after stamping, and special packaging. Uncirculated coins may vary to some degree because of blemishes, toning, or slight imperfections.
The part about satin finish no longer applies, but the rest of it is certainly true (slightly higher coining force, early strikes from dies, special cleaning after stamping, and special packaging).





















