FREDERICK, Md. -- Customers are paying more for their favorite beers, but they don't seem to mind.

The cost of brewing beer keeps getting higher thanks to a short supply of ingredients and rising fuel costs.

The cost is being passed on to customers in the form of higher prices, but beer sales continue to climb.

Matt Brophy is the master brewer at Flying Dog Brewery in Frederick, which is Maryland's largest independent brewery, bottling 90,000 beers a day.

Recently the brewery has had to deal with rising fuel prices and a falling supply of key beer ingredients, including hops.

"If you're paying $3 a pound last year for hops, you're paying up to $9, $15, as much as $20 a pound," Brophy said.

The smaller breweries are the hardest hit.

"More so the small guys than the larger ones because they have economies to scale, but all across the board nationally, brewers have had to raise their prices," said Chris Rippe, Flying Dog's marketing director.

Flying Dog has been forced to raise its prices between 50 cents and $1 for a six pack. Government data shows the price of beer at supermarkets is up about 4 percent since this time last year, the biggest spike in recent years.

Industry analysts said they expect prices to continue to rise as beer makers are forced to pass along those higher costs.