Coffee Macronutrients: Carbs (50%), Proteins (13%), Lipid (15%)
Much of the flavor of coffee is developed from the roasting, which involves the denaturing of coffee proteins, the Maillard reaction between these proteins and sugars, and the caramelization of those sugars. But the fermentation which precedes the roasting provides the necessary compounds which compose the varied and rich aromas / flavors that form during the roasting process. There are two primary ferments which occur: (1) starches and complex sugars on the fruit surrounding the bean and in the bean are broken into simpler sugars, which caramelize during the roasting and are more available for the Maillard reaction, and (2) coffee proteins (albumen, globulin / vicilin, etc.) are broken down by proteases into amino acids (alanine, glutamic acid, threonine, etc.), which when roasted form the many unique flavor compounds (savory flavours, fruity flavours, etc.) which give coffee its complexity. This is both bacterial and fungal. The entire process has two basic steps: fermentation and roasting.
Coffee, however, does not grow in the northeast United States. Much of the fermentation of the coffee can only be done on the fresh bean, and also relies on the outside fruit, which not only is the partial substrate of the fermentation, but contains natural enzymes and sugars for bacteria and fungus to reproduce, who themselves create enzymes which aid in breaking down the fruit and the bean.
So, in order to recreate this two step process, you must recreate the fermentation by introducing exogenous enzymes. This can be done with raw honey, fresh fruit, or malted grain. Perhaps the most promising, though, is koji, which contains both amylases and proteases, many of which are the same enzymes which help to ferment coffee beans. You can recreate this as a two step process, by which a bean or grain of choice is fermented by koji (at 140f, to speed up the fermentation and development of simple sugars) and then taking that mixture and roasting it. Alternatively, you can combine the processes of koji fermentation (really, the process of amazake making) and the process of blackening (which is both enzymatic and the development of the Maillard reaction and caramelization), to both ferment the substrate and roast it at the same time. Here are some permutations to be considered:
Dry -> Roast -> -> Grind / Steep
Dry / Blacken -> Roast -> Grind / Steep
Dry / Blacken (w/ koji enzymes or flavourzyme) -> Roast -> Grind / Steep
Dry / Blacken (w/ raw honey / fruit) -> Roast -> Grind / Steep
Dry / Blacken (w/ malted grain enzymes) -> Roast -> Grind / Steep
Potential Substrates: fava beans (Rich in vicilin (7S globulin), legumin (11S globulin)), lentils, barley, buckwheat
Others: soybeans, rye, spelt, stale Bread