A good chocolate porter that delivers on its promise of silky, elegant chocolate character is fairly simple to formulate and brew, yet can be devilishly difficult to execute well. After tinkering with recipes and processes for several years, I have found a few secrets that have helped me consistently win competitions with this style (entered as a Herb/Spice beer).
Start with a good solid recipe for a porter or stout, and practice perfecting the basic flavor profile. Don't worry about trying to emphasize the chocolate character at this stage. You will use some chocolate malt to simulate some aspects of chocolate flavor, but the addition of real cacao will provide the sought-after character: chocolate aroma and flavor reminiscent of quality dark chocolate.
I have found that using an American robust porter base recipe works well (ABV target around 6%±0.5%). The alcohol content helps deliver the aroma by volatilizing the aromatic compounds in the chocolate.
|3%||chocolate malt (Carafa)|
|1%||black patent malt|
|1 oz. low cohumulone, high alpha acid hop (first wort or 45 min boil)|
|1 oz. low alpha hop (20 min boil)|
|Ferment in low- to mid- 60s.|
|Add cacao nibs and vanilla beans to secondary, age 1-2 weeks depending on desired level of flavor and aroma extraction.|
|Bottle condition for best results.|
The following table contains tips and rationales important in working with chocolate (and vanilla).
|Do not use milk, semi-sweet or baker's chocolate.||These chocolates contain cocoa butter and other lipids that can harm the beer's head and lead to staling as the fats go rancid with age and oxygen exposure. Even distribution of the cacao solids in wort or beer requires melting the chocolate and stirring. There is no good way to do this without releasing the fats.|
|Do not use cacao in the boil.||Boiling or hot extraction leads to a thinner, more insipid cacao character.|
|Do not use cocoa or cacao nibs in primary fermentation.||Cacao contains antifungal agents that may kill or inhibit yeast. Best case is a long lag time; worst is an infection.|
|Use cacao in secondary fermentation for best results.||Cold extraction, particularly with the aid of alcohol, improves the flavor and aroma profile of the end product. There are no issues with lipid extraction in cold temperatures used for secondary fermentation (low 60s).|
|Limit contact time; taste periodically to determine the level of extraction.||Nibs may need up to 1-2 weeks of contact time for best results. Cocoa powder (alkali process; defatted) does not require nearly as much time due to the far greater surface area exposed to the extracting medium (beer).|
|I use 6-8 oz. cacao nibs in 5 gallons, or 1-2 oz. cocoa powder in 5 gallons. This varies by supplier; you will have to do some experimenting to find the best cocoa powder or nibs. I prefer nibs.||Don't overdo it! The idea is to leave the base beer qualities evident while enhancing the chocolate character.|
|Use less bittering hops than you think are necessary for the base beer style.||Cacao and cocoa powder contribute considerable bitterness, albeit of a somewhat different character than hop bitterness.|
|Use less cacao/cocoa in a strong beer.||Extraction of the organic aroma and flavor compounds increases with alcohol content. This is one parameter you have to work out by trial-and-error. Add some vanilla beans to round out the flavor profile. Works pretty well for chocolate chip cookies, doesn't it?|
|Do not use vanilla beans (or extract) in the boil.||Vanilla beans exude considerable oils that may interfere with head retention and contribute to staling. This is not an important factor for sodas, so go ahead and boil your vanilla when making cream soda. The flavors and aromas from vanilla extract will be lost during the boil.|
|Use vanilla beans (or extract) in secondary fermentation.||Vanilla beans are okay in primary, but a lot of volatiles are lost in the vigorous CO2 blowoff of a good ferment. Extraction is better in the alcoholic environment of the secondary fermentation vessel.|
|Be generous.||I use 2-4 beans in secondary, split and cut into ~2 inch lengths. Expensive, but then I got a bunch of free vanilla beans a while back, so it's free to me.|
|Use less vanilla in a strong beer.||See above comments about alcoholic extraction of volatile components.|
|Take your time. Young chocolate beers are pretty unapproachable.||The alkaline bitterness is startling at first, but fades with time. The flavors mellow and mingle with age. Give it a couple of months to come into its own.|
|Bottle condition these beers.||My opinion. The yeast does continue to work despite the presence of some suspended cocoa/cacao particles. I have found that bottle conditioned chocolate porters are more subtle and drinkable than force-carbonated versions.|