What are some ways to make low-carb beer?

Question

I and a few friends have dabbled with the various "low carb" diets. But I've found that after a while, you don't want to break the diet, but just want a beer.

What are some ways to make a beer recipe lower carb?

Bonus question: Is there a way to calculate how many carbs/sugars are in the beer? I think the fermentation process would mean that sugars that were in the beer are no longer (hence the falling gravity), but what does a FG of (say 1.010) mean in terms of how many grams of carbs/sugars in a beer?

Answer 1

Counting Calories in your Homebrewed Beer has some relevant information.

The best way is to keep to session beers with a good bit of adjuncts, so the yeast eat as many of the carbs as possible. I made an ordinary bitter with 25% of the fermentables as honey that rings in at around 117 calories per 12oz.

Answer 2

Start with a low OG beer, then use something like amylase enzyme to make sure that it ferments out as completely as possible.

Answer 3

White Labs has an amylase product called Ultra-Ferm. It's a blend of the alpha and beta enzymes and is recommended in either high OG or low OG recipes (I used it en route to a 21.4% behemoth)

As recommended by others use corn, rice, or sugar as an adjunct as a good chunk of your grain bill (20-25%) and use an enzyme. Don't expect a super flavorful experience. Light beers show every process/fermentation flaw and are straight tough to pull off but don't let keep you from experimenting.

As for caloric calculations a good brewing software could spit out nutritional value by recipe. Good luck!