Here are portions from an upcoming article I have written for Edible Sacramento.  Look for Port 101: An Everyday Primer in the Winter 2013 edition online and at local distribution points in February.

During the months of the year when the Valley fog chills you
to your very core, it is not uncommon to hark back to the virtues of port.  Few beverages can bring warmth to a frozen
body – this fortified wine, with its alcohol level approaching 20%, is one of
them.  Through the centuries port has
captured the souls of travelling sea farers, the British Aristocracy and
everyday man.  Nary an episode of Downton Abbey goes by without Lord
Grantham slugging back some of the stuff.

There are a number of liberties taken by port makers around
the world, which can be frustrating when trying to define different port
styles.  I’m giving it the ole’ college
try.  The jewel of the port world is
Vintage port.  The most expensive of all
ports, a vintage blend  is aged a short
time in cask and if the port of that year is determined to be superior and
age-worthy, it is “declared” as a vintage and 
bottled unfiltered and unfined and left to age in the bottle.   These
ports are not usually ready to drink for 20-30 years and can last up to 100
years or more! These decadent ports are loaded with sludge, and upon opening, require
skilled decanting to rid the wine of sediment. 
    

Crusted port is sort of the cheap man’s vintage port.  It is a blend of vintages that is bottled
without fining and filtration, resulting in “crust” or deposits of sediment in
the bottle.  It is exported and ready to
drink three years after bottling; it requires decantation.

In the cask aged
category, red ports are traditionally young, fiery, fruity and a blend of both vintages
and vineyards.  Ruby is the simplest
port, and a Reserva is basically a Ruby on steroids.   Both are produced using deep and dark red
grapes (i.e., Touriga Nacional, Touriga Franca, Touriga Barroca, Tinto Cao, and
Tinta Roriz) and aged approximately 1-3 years before bottling.  These wines are technically ready to drink
upon release.  Some Ruby and Reserva
ports are produced from single vineyards (or quintas) and single vintages.   LBV (late
bottled vintage) is essentially a Ruby of a specific vintage that stays in cask
for 4-6 years and is subsequently bottled. 
It requires no additional aging in the bottle, and depending upon
whether it has undergone filtration, an LBV may need to be decanted.  These ports are often made from vintages
deemed quite good, but not technically “declared vintage” years.

Tawnies are likely named as such as because they are
brownish and tawny in color.  Light or young
tawnies-often the same age as comparably priced ruby ports- usually acquire
their coloring from a bit of oak aging, but also from the fact that they are
produced using grapes from slightly cooler areas of port grape regions,
resulting in less intensity of color. 
Additionally, sometimes, port made from white grapes is added, also
affecting color.  These lighter, crisp
and acidic tawnies are quite popular as chilled aperitifs in France.

Aged Tawnies are intense and nutty and have spent a minimum
of 6 years in cask.  Deeply tawny in color,
these ports often display caramel and butterscotch flavors within their silky
texture.  The best tawnies are identified
as aged in cask either 10-20-30- or- Over 40 years.  As bottled tawnies are a blend of vintages,  true age is approximate, except in the case of
Colheitas, which are tawnies produced from a single vintage.

White port, also aged in cask, is relatively uncommon
outside the continent, and is made from, you
guessed it, white grapes; some examples are dry, others quite sweet.  

I chose to study a couple local ports produced by
Revolution Wines and one by Bogle Winery. 
I have tasted these ports in the past and wanted to have my own little
“throw-down”.  In an interview and visit with
Revolution’s winemaker, Craig Haarmeyer, I learned about the two styles they
offer:  the 2009 St. Rey Single Quinta Ruby Port, and the 2008 St. Rey LBV.   It was great to be able to observe the
differences between the two styles. 

 Both Revolution products are made from rare and traditional Portuguese grape varieties including
Touriga Nacional, Tinto Cao, Tempranillo, Souzao and Alvarelhao.   All of the grapes are sourced from the Silva Spoon Vineyard of Ron Silva—for
all intent and purpose a “quinta”, located in the Alta Mesa appellation in
Galt.  Haarmeyer buys roughly equal
amounts of the varieties, ferments them separately and then makes his decision
on the exact blend.

…The first words that came to mind for me when I tasted the Revolution ports were “surprising” and “elegant”… 

Read the complete background story on port, as well as detailed reviews for Revolution, Bogle and a 1955 Antonio da Rocha Leao Vintage Port in February.  xoSB