If you’re a savvy tippler, you already know the best time to buy booze and where. Now, science has officially answered the question of which wine is the least likely to have you reaching for your trusty bottle of Advil tomorrow morning.

According to Professor Steve Allsop, of the National Drug Research Institute in Perth, Australia, it all comes down to the evil little morning-ruiners called congeners. When your body breaks down the congeners found in wine, toxins are released — and it’s those toxins that make you feel like a pile of poo after a carefree night of celebration.

So how do you know if your wine has a lot of congeners in it? Look at the glass in your hand. Congeners contribute to the color and flavor of alcoholic beverages, so the darker the wine you’re sippin’ on, the worse you’re likely to feel tomorrow. Meaning that the age-old debate over red wine versus white has been officially, scientifically solved: red wine will give you a worse hangover.