Why is beer more calorically dense than its macronutrient contents?

Hi,

I love reading up about dieting but there seems to be something that is tripping me up at the moment.

To my understanding the way a calorie count to its macronutrients would work is:
1g of protein = 4 calories
1g of carbohydrates = 4 calories
1g of fat = 9 calories

I recently went out for a few drinks and to my suprise when put into MFP my macro nutrients and calories just didn't add up.
After researching this I found that the nutritional information that was put into MFP was correct.

So what gives?

Example: typically the nutritional information in 440ml of beer is:
141 cals
1g protein
14g carbohydraps

14 x 4 = 56 + 4 = 60?

Any help would be appreciated thanks.