Source: J.P. (firstname.lastname@example.org), r.c.b., 4/27/95
They explain to bring the grains to a boil in a gallon of water, without boiling the grains; strain, and sparge with a quart of hot water, into the brew kettle.
Add a gallon of water to the brew kettle, and bring to a boil. At boiling, add the 2 cans (6.6 lbs) of Munton & Fison Dark Plain Extract. Stir, don't let it stick at the bottom. Bring to a boil, add 2 oz of the Styrian Goldings. Boil 30 minutes, add the two cans of syrup, and the teaspoon of Irish Moss. Boil for 28 minutes more, add the remaining 1/2 oz of Styrian Goldings. Boil two more minutes, and turn off heat.
Usual procedure for wort cooling, addition of the yeast (pre-prepared) and bottling (use 3/4 cup corn sugar for bottling).
I chose to add the Maple syrup ONLY after 30 minutes, mostly because I was a bit worried that the wort my overflow because of the syrup (that stuff, boiled solo, will almost always overflow!). I was also concerned that the syrup would be "over-cooked". You may want to put it into the brew kettle at first.
My fermentation was rather FAST, it took about 36 hours, and at that point, the air lock was only going about once every 2 minutes. I bottled on the 10th day, to be sure.
My O.G. was 1.070, but it may vary depending on the syrup you use. My F.G. was 1.020, and again, it may vary. I found that he color of the Porter will be mostly black, with a slight pull towards brown.