PULLMAN, Wash. — A Washington State University enologist has become an expert in the art and science of fine-tuning rosé wine colors.
Asked by Washington winemakers how to more precisely develop wine colors, associate professor Jim Harbertson and graduate student Caroline Merrell have found that sulfur dioxide management is an important factor in rosé wine color.
They have come up with a guide for winemakers to follow that allows them to predict color changes analytically and achieve that gorgeous shade of ballet-slipper-pink or deep rouge.
“What’s significant is that our study provides tools to winemakers to measure apparent and potential color in their rosé wines. There’s more science and less guesswork involved,” Harbertson said.
Rosé was considered as sweet and cheap about a decade ago, but now it’s regarded as chic and sophisticated. Sales rose 40 percent in 2017, according to Nielsen market research.
“More than other wine types, color heavily influences consumers’ perceptions of rosé. This makes winemakers particularly mindful of achieving just the right color,” Harbertson said.
Rosé stands apart from other wines in its diversity of hues, shades and tints. Though aroma and flavor are important to consumers, studies say the number one factor is its pinkish charm.
Rosé’s color also signifies its style. A light-colored rosé is expected to be a lighter-bodied wine and a darker one to be more full-bodied, Harbertson said.
The trick to perfecting color is the timing of exposing dark wine grape skins to juice, 2 to 48 hours, with the wine lightening during fermenting and darkening after bottling.
“Rosé may be easy to drink but it is not easy to make,” he said.
His study was recently published in Catalyst, a journal by the American Society for Enology and Viticulture.