I liked your recipes using Mt. Dew and other sodas in beer and I was wondering if the same thing would be possible with commercial root beer? I was thinking of making a stout/porter type ale and fermenting with root beer to get some of those flavors in the beer. My question is would you run into the problem of bottle bombs like you can with home made root beer?
— Russ Albright
Sure, the same thing would be possible. Like other sodas, root beer is just fizzy sugar water with some flavoring added.
You shouldn’t run into problems with overcarbonation, because all the root beer sugars will ferment away during primary fermentation. In the case of homemade root beer (the soda), some people add yeast to a sugary solution and then try to stop the fermentation once the proper level of carbonation is built up.
There are two ways you could approach brewing a root beer beer. Adding actual root beer to the wort (or as part of your dilution water in an extract beer) is one possibility. Another is to use the “roots” to spice your root beer beer.
If you use the soda, you will be able to control the level of root beer flavor in your beer. However, you may end up with a drier beer than you’d like. The sugars in root beer — usually high-fructose corn syrup —are 100% fermentable. [And incidentally, the specific gravity of (decarbonated) sodas is usually around SG 1.046.] So, the more root beer you use, the drier your beer will be. If you want make a dry beer, this isn’t a problem. But if you want a full-bodied root beer beer, this is not the way to go.
Incidentally, some brewers wonder if the preservatives in soda will inhibit the fermentation of a soda beer. I have not found this to be the case. Most sodas are preserved with enough sodium benzoate to suppress stray contaminants. However, there is not enough to bother a full pitch of brewers yeast.
Your other option is to use the spices used in root beers. The major spice in modern commercial root beer is wintergreen. Other spices were used in the past. Many homebrewing and home winemaking shops sell the individual spices, or spice blends, for home root beer (soda) making. The packaging will also likely give you guidelines for how much to use. Most also sell liquid root beer extracts.
The flavors of root beer may be less recognizable when not paired with the usual sweetness of the soda. To give your beer a hint of sweetness to accentuate the root beer flavor, you could try adding some lactose. Lactose is a sugar that is not fermentable by brewers yeast. Lactose is much less sweet than glucose, sucrose or fructose. Still, you likely will need only a hint of sweetness to complement the root beer spices. As such, adding about 1 pound per 5 gallons of beer should do the trick. Boil the sugar with your work.
Send your questions to firstname.lastname@example.org. I’ll answer you (and inexplicably post a cat picture).