Sugar will carbonate your beer

If you bottle your homebrew, you know how sugar is used for carbonation.  The reason we use sugar is to use something neutral in flavor.  You don’t want to change the flavor of your beer at this point.  Usually corn sugar, table sugar, or rice syrup solids are used to carbonate the beer.

If you force carbonate, you will notice little to no difference in the flavor of the beer.  The carbonation (if equal) will be the same from force carbonating or bottle conditioning.  Carbon dioxide is the same, regardless of the source.

Other recipes can add other sugars at bottling to give the beer a little extra flavor.  These cases are rare, but you might come across a recipe using something other than the normal carbonating sugars.

Sugar will lighten the body of your beer

Sucrose sugar (cane or beet sugar) is completely fermentable.  It will not increase the body of your beer since the sugar will convert completely to alcohol.  Since alcohol is lighter than water, the beer is much lighter and thinner.

Sugar is commonly used in Belgian beers to lighten the body of their higher alcohol beers.  The sugar the Belgians use is actually a liquid form for the Belgian candi.  According to “Brew like a monk”, Belgian brewers use either the liquid form of Belgian candi sugar or they use sucrose and dextrose.  The liquid syrup used is about 65% sugar.
A good example is Chimay , Duvel, or other strong Belgian ales.  These beers push 9% ABV, but they have a light mouthfeel.

Most of my neighbors have learned the hard way; lighter beers do not mean lower alcohol.  The first summer I brought out my tripel, most people hit it like you might drink Budweiser.  Because the beer was lighter, they didn’t know they were in trouble until too late.  The beer is now named “Tripel Trouble” to warn newer neighbors.

Sugar will increase the alcohol in your beer

The “trouble” in the beer was the higher alcohol.  Table sugar will add about 1.046 points per pound per gallon.  So if you add one pound of sugar to a five pound batch, you should see a gravity boost of about 1.009.  If you’re looking to increase the strength of your beer without increasing the body, sugar is your answer.

Some extreme beer recipes, where the alcohol content is close to 20% ABV, slowly feed the fermentation with sugar over time.  As the yeast ferments the sugars in your beer, some yeast adapts to the harsher conditions in your wort.  You feed the yeast more sugar and nutrients until you reach the alcohol content you’re targeting.

Other sugars like honey, maple syrup, or corn sugar will also add varying amounts of fermentables to your beer.  Maple syrup will add the least (about 1.031 per pound per gallon), while table sugar adds the most.  Everything else is somewhere in between.

One sugar that will not increase the alcohol is lactose.  Yeast cannot ferment lactose, so this sugar will stay in your beer to the end.  Lactose is used to sweeten some stouts and give the beer a smooth “milky” mouthfeel.

Some sugars can alter the flavor and color of your beer

Dark Belgian candi will change slightly the color and flavor of your beer.  The darker candies will impart intense molasses and burnt-caramel characters to your beer, and possibly darken the beer.  The amber candi has a butter caramel flavor.  The color change really depends on what color your beer was when you started, but amber candi usually has a Lovibond rating of 75° L and dark candi has 275° L.

Brown sugar is just normal table sugar with some molasses added.  Molasses will give your beer a rum like character.  Honey and maple add honey and maple notes to your beer (of course).

Sugar should not make your beer cidery

Well the good news is sugar shouldn’t make your beer cidery.  If your fermentable list is more than 20% sugar you may get something that cidery, but I think the cider flavors from sugar is more myth than reality.  I’ve never used more than 20% sugar in a batch, so I can’t say for certain if it will make your beer cidery.  The most sugar I use is in a Chimay White clone which has no cidery flavors, and a cider which is supposed to taste cidery.

If you add too much sugar, your beer will just be sweet.  If your starting gravity is too high, the yeast may have troubles starting or fermenting to completion.