Whether you tend bar professionally or are just a home mixologist, at some point, someone will want to play a round of "Stump the Bartender" to test your knowledge. As craft cocktail culture has evolved, the questions have gotten a little more … interesting. To supplement your cocktail knowledge, we’ve put together a list of questions often lobbed at bartenders.

1. IS VODKA MADE FROM POTATOES?

Yes and no. Potato vodka only makes up between one and five percent of what’s on the market. Most of the rest is made from grains like wheat, but some distill from grapes, corn, sugar, or even milk. The potato wasn’t introduced to Europe until the 1500s, but the word “vodka” first appears in print in 1405, as part of a medicinal recipe. Early vodka was made from grain, just as it is today. The potato connection is thought to have sprung up in the 1700s or so, and by the early 1800s it was the dominant base for the spirit.

2. HOW MANY GRAPES GO INTO ONE BOTTLE OF WINE?

In a nutshell, the number is around 600-800 individual grapes, or about 10 grocery store-sized clusters. What you can buy in the produce section typically contains three clusters, so, in theory, you could make a bottle of wine out of three bags. So why is some wine so expensive? Just as organic produce is more expensive to produce, grapes that are dry farmed (made without irrigation) or organically or biodynamically produced cost more to grow. Their yields are also usually smaller, so the wine that those vineyards produce is more expensive.

3) BOURBON HAS TO BE MADE IN KENTUCKY, RIGHT?

Although 95 percent of bourbon was produced in Kentucky as of 2013, bourbon can be made anywhere in the U.S.A. That is, as long as it’s distilled from a mixture of grains that’s at least 51 percent corn, contains no additives other than water, and is aged in new oak barrels. There’s not a minimum age requirement to be called bourbon, but to be labeled as a “straight bourbon,” it must spend at least two years in oak barrels. 

However, if it’s aged for less than three years, there’s a possibility that it might not be legal to label it as whiskey. Some countries, including Canada and the EU, require that a spirit age for three years to be called whiskey. As a result, some bourbon is labeled as “bourbon,” but not “whiskey,” overseas.

4) WHY CAN ALL CANADIAN WHISKY BE LABELED AS RYE?

Under Canadian law, all whisky produced there can be labeled as “rye whisky,” “Canadian rye whisky,” or “Canadian whisky.” More than two centuries ago, Canadian whisky makers started using a bit of rye to add spice and depth to their booze. Consumers who wanted this more complex style would ask for the “rye whiskey,” and it stuck. More interestingly, this slang was in use more than 150 years before the U.S. passed regulations requiring that “rye whiskey” must be made from 51 percent rye. The Canadian Food and Drug Regulations is a little different. To be labeled rye, the whisky must “possess the aroma, taste, and character of Canadian whisky.”

5) WHAT DOES A DECANTER DO?

Put simply, decanting whiskey or wine is done by pouring a bottle into another vessel before serving it. For wine, decanting does two things. First, it separates the liquid from the sediments that might have settled in the bottle. Second, it forces oxygen into the wine itself, which can “open up the wine” to release more complex flavor and aromatic compounds. For whiskey, it’s mostly for show. Oxidization reactions happen much more slowly for distilled spirits, meaning that any changes in the appearance or taste will happen over a much longer period of time.