Brew #2: White House Honey Porter

Just in time for our next brew, the Internet brought to my attention the fact the White House had released its own homebrew recipes. The recipes looked pretty simple, and the video showed that they were using the same basic kit we were. We decided the porter would fit nicely with the cold, dark winter.

Recipe: Here's the PDF. Lots of grains and malt extract, vaguely specified hops, a pound of honey, and Nottingham yeast.

Feedback: Everyone loved it. "Seriously, this is one of the best beers I've ever had." -- a friend. By my calculations the alcohol content was around 6%, but empirically it seemed stronger than that. I would normally split a bottle with my wife in the evening.

Let's learn about: ABV

How did we calculate the alcohol content? With science.

The density of dissolved sugar is greater than that of pure water. We measure the ratio between the densities of the liquid in question (our brew) and water as the specific gravity (SG), using a hydrometer, which is basically a weighted buoy with tick marks. The deeper the hydrometer sinks into the liquid, the lower the liquid's specific gravity.


Yeast converts sugars (sucrose, fructose and glucose, mainly) into ethyl alcohol and carbon dioxide gas. Because the gas bubbles off through the airlock and the remaining ethyl alcohol is lighter than the original sugar, the SG of the brew decreases during fermentation, approaching that of pure water (1.0).

So, we can calculate the amount of alcohol produced during fermentation by comparing the SG measured before fermentation (original gravity, OG) to that of the finished product (final gravity, FG). Subtract the FG from the OG to get a number indicating the amount of sugar that was fermented, and multiply by a magic constant to convert the units to percent alcohol by volume (ABV). The formula is:

%ABV = 131.25 * (OG - FG)

For this brew, I measured OG=1.064 and FG=1.020, for a difference of 0.044. So the alcohol content was 131.25 * 0.044 = 5.775 % ABV.

Grains of Fury: First Brew

Last October some friends and I, seeking high-quality booze on the cheap and an outlet for our unused scientific creative energies, went in together on a homebrew kit. Brewer's Best sells a basic equipment bundle and a line of ingredient kits that include bottle caps, a bottle crimper, non-surfactant sanitizer, and some other odds and ends. We started with something seasonal.

Recipe: Brewer's Best Pumpkin Spice Porter

Synopsis: Following the included time schedule, boil the bag of malted, milled grains, add malt extract, add hops and spices, cool to room temperature and transfer to the fermentation bucket. Add yeast. Ferment in the bucket for a week, then transfer to a clean glass carboy for another 3 weeks to let it mellow. Add 3/4 cup corn sugar (this triggers enough additional fermentation to carbonate the beer) and bottle. Wait at least another 2 weeks, chill and enjoy.

Let's learn about: Water

We used water from the local grocery store's bulk water machine, purified by reverse osmosis and therefore very soft. The notion is to avoid chlorine and other off flavors that might be present in tap water.

Our brew's flavor was nice -- we liked the spices, and beyond that the taste was very clean. In fact, the beer had a strangly light, refreshing body to it, much like spring water. Once you noticed it, it was hard to ignore. Still drinkable, though. As a side effect (I think), the beer had very little head when poured, almost like pouring Diet Coke. Feedback was positive overall, and only the most dedicated beer aficionados noticed the water issue.

To address the water issue in the next brew (a porter, see next issue), we picked up some gypsum and added 2 tsp. to the wort at the boil. This worked quite well; the brew had a mouth-feel just like Real Beer. Traditionally porters are brewed with softer water than, say, a pale ale, so 2 tsp. was a little too much for the porter (I could taste a hint of gypsum, though I was looking for it) and 1.5 tsp. would probably be better, while 2 tsp. would be just right for a pale or amber ale.

Cooling off your brew

Because water has a high heat capacity, it takes hours for the boiling-hot wort to cool to room temperature on its own. In our first run we put our pot in the kitchen sink with cool water and ice, and continually stirred the surrounding water and replenished the ice until the temperature came down to a level the yeast could tolerate. This still took a long time, and during this time there is a risk of bacteria or other fungi including wild yeast could infect the wort (in the absence of competition from our chosen yeast).

Since then, we've been using a quicker method:

1. The day or morning before brewing, take the primary fermentation bucket to the local grocery store and fill it with 5 gallons of clean water.
2. Transfer about 3 gallons of the water to various containers (other than the brewing pot) and refrigerate.
3. For brewing, put 1.5 gallons of the remaining clean water into the brewing pot. A small amount of water remains in the bucket.
4. After the boil, pour the wort into the bucket, slowly and from a high level. Stir aggressively for several minutes. (This also oxygenates the wort a bit, which helps the yeast grow initially.)
5. Once the wort has come down in temperature a bit, pour the refrigerated water into the wort to bring the final temperature to 75-80 F (~25 C).
6. Before pouring the last of the refrigerated water, float bags of ice in the wort to bring it closer to the target temperature. (Sanitize the plastic bags of ice before dipping into the wort.) The ice bags will be less effective when the temperature is close to the target, while the effectiveness of the refrigerated water is essentially linear.