Ordering a blush wine at a restaurant has been known to make wine purists, well, blush. They're as beloved by casual drinkers as they are reviled by snobs, but one thing is certain: they're a refreshing, not presumptuous summertime classic. No picnic basket would be complete without a bottle tucked in for a jubilant sunny-weather swig.
Northern California's Almaden Vineyards launched the first American blush wine in the early 1940s. It was Grenache Rosé, a distinctly pink wine with a sweet kick. It was successful enough on the market for that success to be a detriment; "serious" wine connoisseurs turned up their noses, and the public at large began to think that blush wines were necessarily somewhat sweet. When the Sutter Home winery introduced their White Zinfandel in the 70s (by spectacular accident, when the yeast that normally ferments the sugars in their production of zinfandel died), blush became a household name. The wine was sweet and swillable, and wineries that produce the most of it (Sutter Home and Beringer) still make a killing from that particular juice.
It's important to note that the juice of any grape is clear, or "white." It's the grape skins that add two important elements to the wine: color and tannins. The introduction of color is simple--the longer the skins are left with the juice, the deeper the color of the liquid. Tannins are a bit more complicated. Put simply, tannins are compounds that plants have evolved to protect themselves against bacteria and fungi. In grapes, tannins are located in the seeds and stems. Because tannins constrict the mucous membranes, they have an astringent effect on the mouth. That feeling of slight constriction gives the wine its "structure." There are four ways to introduce these elements during the wine making process to produce a blush wine.
The first method used to produce blush wine is called "limited maceration." Quite simply, this means that the grape solids are left in the juice after crushing. After waiting for a certain period of time, the winemaker then "racks" the grapes, which essentially means straining out the stems, seeds and skins. A paler blush is achieved if these bits are only left in for a short while; the longer the seeds, stems and skins are left in, the darker the wine. Typically, the solids will be left in the juice for just a few hours (six to eight).
The second method, saignee, is a process whereby some of the juice from the crushed grapes, called "must", is bled off of the mixture before the fermentation kicks into gear. The rest of the wine becomes "regular" red wine, and the juice that was taken from the lot is then mixed with "white" juice and crafted into a blush.
The third method, pressurage, also called "direct pressing," utilizes traditional white-wine grapes with naturally darker skins. It's generally held to be the most refined of the blush methods, and is used most commonly by blush winemakers in France's Provence appellation. Which, unlike most of the rest of the wine making world, is dead serious about blush and rosé. The darker skins of the grapes, left in the mix for a bit, provide a pinkish color while lending their tannic "backbone" to the wine.
You're unlikely to see the term "rosé d'assemblage" anywhere but a Champagne bottle, but this method of creating a blush--simply mixing a bit of red wine into white wine--is uncommon, but not extinct. Viewed by many winemakers and connoisseurs as "cheating," rosé d'assemblage is usually the method whereby pink Champagne is created.