“I have seen some of the same grapes used to make ‘blush’, ‘blanc’, and ‘rose’ wines. In some cases from the same winery! Could you tell me the difference?”
I’m not sure that I can because there is no code, law, or regulation which governs the terminology regarding the color of wine. Each producer can use the terms interchangeably even though it may be confusing for the consumer. All three of those terms can be used for blush wines but they do not tell whether one is dry, medium or sweet! Let’s explain the process.
A wine grape whether white or red, is composed of skin, pulp and seeds. While the skin is red in Merlot, Zinfandel, or Cabernet Sauvignon the pulp is actually white. The natural pigment in the grape resides in the skin cells. When red grapes are crushed, they are left to ferment on the skins. During this fermentation the skins impart their color to the resulting wine.
If you lightly crush the red grapes and draw the unfermented juice on the skins into another tank, that juice will ferment without skin contact. This method will make white wine out of red grapes or at least as white as the skins will allow.
Obviously, you have to be fast. Some skins are so dark that even the slightest contact (1/2 an hour) will give the barest “blush” some color. The skin also adds tannins and structure to the wine. Removing them produces a lighter fruitier product, The seeds add harsh, sometimes bitter elements and are also removed. “Blanc” wines receive little or no skin contact. With very fast and rather expensive equipment, it is possible to make a totally white wine from red grapes. If one wants a “blush” of color leaving the grapes on the skins for 2-3 hours should do it
“Rose” wines are left on the skins overnight to give them that pinkish color. They are sometimes referred to as “First Night” wines because they spend the first night of fermentation on the skins. Pink wines can also be made by blending red and white wine together. This can add complexity and depth to a blush wine. And what is interesting is that either of the two methods of producing these pink wines can produce wines that are bone dry to wines that are overly sweet.
As you can see, it is a matter of degree of color and it seems logical that “blanc” should be the lightest, “blush” should be the next level up, and “rose” the deepest pink.
Fortunately, for us, most wineries use a clear bottle for these wines so that we can make our own conclusions.
The bottom line is, experiment and find the ones you like!