The sweet stuff isn’t just for children at Aroa Fine Chocolate. At the South End chocolaterie/patisserie, you will find chocolates seasoned with basil, tea, stout, liqueur, port, ginger and chilies. Consider them NC-17-rated indulgences for grownup trick-or-treaters.

While the ancient Aztecs used to consume melted chocolate mixed with chilies, Aroa executive pastry chef Tim Brown says the other unusual flavorings are modern-day inventions.

“I love candied ginger from Australia and dark chocolate. So the thinking one morning in the shower was why can’t we put ginger in the filled chocolate?” he said. “So we got some ginger at the Haymarket. We put it through the juicer and mixed it with cream and added some dark chocolate. It’s pretty good, if I may say so.”

All chocolate begins with cocoa beans.

“They’re grown around the equator and, like wine, are influenced a lot by where they’re grown, who looks after them, soil conditions and weather conditions,” Brown said. “Most of those beans are then sold on the open market to different chocolate manufacturers and moved across the world to their production facilities.”

The beans are then roasted and crushed into minute particles.

“They put (the crushed chocolate) into what is essentially a big pot with a beater and they churn it - for up to 96 hours - with a little bit of heat,” Brown said. “That allows some of the tannins and volatile acids to evaporate. Then it’s molded into the bars that you buy in the store or they send us.

“The most important part is that the people who are touching the beans know what they’re doing and how they’re doing it. Those skills are passed down through generations. It’s nothing you can read in a book or learn on the computer. It’s all about touch and feel.”

The different varieties of chocolate are determined by the percentage of crushed cocoa beans in the bar.

“Most milk chocolates run between 30 and 40 percent,” Brown said. “Bittersweet runs around 40 to 66; extra bitter - or extra bittersweet, as some people call it - goes from 66 to 100 percent. There are no crushed cocoa beans in white chocolate.”

Brown advises chocolate lovers to store chocolate in a cool, dry environment (not the refrigerator) at a temperature between 68 and 72 degrees.

“We guarantee our product for four weeks after you leave here,” Brown said. “But, hey, who’s going to leave chocolate around for a month? I certainly don’t.”

(Aroa Fine Chocolate, 1651 Washington St., 617-425-4988. aroafinechocolate.com)

Recipe: BAKED CHOCOLATE TART

1 1/2 c. bittersweet chocolate

1 1/2 c. butter

4 eggs

1 1/4 c. sugar

1 13-inch prebaked tart shell no more than 1-inch deep (store-bought or homemade)

Preheat oven to 275 degrees. Gently melt the chocolate and butter together over a hot water bath. In a bowl, whisk together the eggs and sugar until you can draw a figure 8 in the mixture and be able to see it when you’ve stopped whisking. Carefully fold the egg mixture into the chocolate mixture, then pour into the tart shell. Bake for 22 to 25 minutes, or until the filling puffs up and wiggles slightly in the center. Cool completely and refrigerate for at least 4 hours. Serve with whipped cream.