Why does that $40 bottle of wine taste better than the $20 bottle? The quality of the grapes? The care taken in production? Maybe not, says a German study. Part of that superior taste may due to the placebo effect

Researchers at the University of Bonn found that higher-priced wines increased the expectation that the wine would taste better, and that expectation changed regions in the brain that process the sense of taste. Much the same as with placebo drugs, it has an effect simply due to the belief that "Quality has its price."

For the study, 15 men and 15 women around the age of 30 participated in the wine tasting. The tasting took place lying down in an MRI scanner, allowing brain activity to be recorded "online" while participants were tasting the wines.

For each wine, its price was shown first. Only then around a milliliter of the respective wine was administrated to the test person via a tube in their mouths. The participants were then asked to rate on a nine-point scale using a button how good the wine tasted to them.

After tasting, their mouths were then rinsed with a neutral liquid and the next identical wine sample — the very same wine they had already tasted and judged — was given for tasting.

"As expected, the subjects stated that the wine with the higher price tasted better than an apparently cheaper one," reported Professor Hilke Plassmann. "However, it was not important whether the participants also had to pay for the wine or whether they were given it for free."

The researchers concluded that identical wine leads to a better taste experience when expectations are greater due to its price, but the researchers believed the placebo effect was limited. For example, they didn't believe they could pass off very low-quality wine for wine selling for 100 euros.

The placebo effect was confirmed by measurements of brain activity in the MRI scanner. The research team discovered that parts of the medial pre-frontal cortex and also the ventral striatum were activated more when prices were higher. The medial pre-frontal cortex appeared to be involved in integrating the price comparison and thus the expectation into the evaluation of the wine. The ventral striatum forms part of the brain's reward and motivation system and apparently increases the taste experience in this way.

Hundreds of studies have found that wine in moderate amounts, regardless of how its taste is perceived, can provide valuable health benefits including reducing the risk of cardiovascular disease and increasing longevity.