Roasting Coffee in the Field

      Depending on the army and the historical period, the coffee issued to individual soldiers or mess sections could have been green and unroasted. There was a good reason behind this practice: as long as they are kept dry, green coffee beans can last as long as 2 to 3 years and still retain their flavor. But as soon as they are roasted, the volatile oils that give coffee its taste and aroma begin evaporating rapidly. Here is a simplified method of roasting coffee in a field environment.

     If you have no local sources for green coffee, there are numerous purveyors of green coffee on the internet. My personal favorite is BurmanCoffee.com, but most vendors are reasonably priced. Their websites are also a great source for info on home roasting, storing, coffee varieties, etc. Store green coffee beans in a breathable package such as a paper or burlap bag in a cool, dry, dark place  (but not in the refrigerator). Do not store green coffee near food items with a strong aroma, as the coffee may absorb those aromas.

     Roasting coffee in the field is not at all difficult and can produce an outstanding cup of coffee if done properly. Coffee can be roasted in a dry, grease-free steel or iron frying pan. I prefer a cast iron frying pan that is not used for any other cooking, so that the coffee doesn’t pick up any tastes from what was previously cooked in the pan. Do not use a Teflon-coated pan. I highly recommend that you do your coffee roasting outside, using an outdoor grill, a camp stove, or an open fire.

Green coffee beans.

Opinions and techniques vary, but here are several basic recommendations that should be observed: 

Roast coffee outdoors. It will produce fairly strong odors, smoke, and chaff.

Do not crowd the pan. Roast only a single layer of beans at a time, and leave a little surface space for expansion. 

The most important thing to remember while roasting is to keep the coffee beans moving! Do not let the beans set still for longer than 15-30 seconds while roasting. Moving the coffee around is what gives an even roast and prevents burning. Pan roasting will not give you as perfect a roast as can be achieved with a rotating drum roaster, but you can achieve a fairly even roast with practice. 

While roasting, flip the beans as if you were sautéing, or stir with a wooden or steel spoon or spatula.

     Coffee beans will pass through several stages, or styles, as they roast. Once the beans pass the medium light brown stage, the longer that they are roasted:

• Acidity decreases
• Body becomes fuller (until very dark roast, when the body becomes weak)
• Aroma decreases
• Sweetness increases (until very dark roast, when the sweetness drops sharply)

There are several major steps in roasting coffee, and different levels of roasting: 

First Crack

     As you begin roasting, the water content of the beans is heated and expands, causing a cracking sound similar to a crackling wood fire. The beans will expand in size and lose approximately 15% of their weight. The cracking noise eventually stops. The beans will be a light brown or cinnamon color and the surface will be dry. At this stage they will produce a coffee that tastes grassy or sour; keep roasting!

      As the beans continue roasting , they reach the medium light brown or American style roast. If you prefer a lighter roast, you may stop at this point and proceed with the cooling step. 

The coffee beans are at the medium light brown stage.
I moved the beans to one sid in order to show the chaff which is produced.

Second Crack

     After the beans have gone through the light and medium brown roasts, they reach the second crack stage. The beans crack again, and are at the full medium brown or City style. You may stop roasting and proceed with cooling at any stage. If you continue roasting, the beans will start to develop a glossy sheen from the heated oils. This is the medium dark brown or Full City  or Viennese style roast, a stage preferred by many. 

The coffee beans are going from medium dark brown to dark brown roast.
Notice the large amount of smoke. This is normal, and not a cause for concern,
as long as you keep the beans moving.

      If you prefer an even darker roast, continue roasting until the beans develop a shiny surface. This is the dark brown or French or Espresso style roast, and is the style preferred in many European countries (and my personal preference). Beyond this stage is the very dark or Dark French style roast. Beans at the very dark stage will have a very shiny surface.

Coffee bean roasting stages, clockwise, from upper right: 

Light brown/cinnamon

Medium light brown/American

Full medium brown/City

Medium dark brown/Full City/Viennese

Dark brown/French/Espresso

Center: green coffee beans

Cooling

The beans should be immediately cooled once the preferred roast stage has been achieved in order to stop carryover cooking. Pour the beans into a metal colander or bowl and swish them around, or pour back and forth between two containers. This also helps to eliminate the chaff. Large amounts of chaff can give the coffee an “off” taste.

Be careful! The beans will still be quite hot, and can cause some very painful burns.

Curing or De-Gassing

     Although not always feasible in a field environment, the freshly roasted beans need to rest and develop their flavor. Before grinding, store the freshly roasted (but cooled) beans in an airtight container for a minimum of four hours, up to about 24 hours. The time needed to develop full flavor and aroma depends on the type of bean, roast, and most importantly, individual preference. I know that the average soldier would probably not have been able to wait 24 hours, but unless you're participating in a one-day re-enactment or under threat of a surprise offensive by the Boche, then it's worth the wait.

Storage

     If kept in an airtight container, whole bean roasted coffee can remain fresh for 7 to 10 days, but is best consumed as soon as possible. Grind only the amount of roasted coffee beans that you need for immediate use. Once ground, the beans begin to rapdily lose the volatile oils that give them their flavor.

Grinding

     Grinding coffee beans in the field is not too problematic. During the US Civil War, soldiers would grind the beans between two rocks or use a rifle buttstock and a rock. Many years ago a fellow soldier told me of how his Texan grandfather would still grind his morning coffee with a hammer and a brick, then throw the grounds into a pot of boiling water over an open fire, resulting in what my friend insisted was the best coffee he ever drank.
     Of course a more elegant solution was for the soldier to procure a small commercial hand-cranked coffee mill, or as was the case of the French army, to issue a standard coffee mill (below). German rolling field kitchens (gulaschkanone) were equipped with a coffee mill.

French Army Coffee Grinder M1896 (Moulin a café " KLEPPER "Modèle 1896).
The "klepper" was issued at the basis of one for every 2 squads. (http://lepoilu-paris.com)

Canteen Cup Coffee (aka Cowboy Coffee)

     Few things are more comforting than a hot cup of java after a cold night spent in the field. The following methods are a basic, simple way to make "field coffee" (and we don't need no steenkin' French presses or no fancy perky-lators!). 

Method 1      

Place 2-4 mess kit spoons (2-4 tbsp) ground coffee and 16-20 fluid ounces (475-600 ml) cold water in a canteen cup or similar container. Bring to a boil and immediately reduce heat or remove from heat. Let brew for 4 to 7 minutes and the grounds have settled to the bottom

Method 2

Using measurements in Method 1, place coffee grounds in a canteen cup and pour boiling water over the coffee. Let brew for 4 to 7 minutes and the grounds have settled to the bottom.

With any of the above methods, pour the coffee off of the grounds into another container or just stop drinking when you get to the grounds at the bottom of the cup.

The US Army's official 1916 recipe for coffee for one man was as follows:

Yield: one medium strength cup of coffee

1 heaping spoonful coffee
(the US Army mess kit spoon was one tablespoon (1/2 fluid ounce or 15 ml.))
2/3 cup (5.3 fl oz/ 160 ml) water

Add the coffee when the water is boiling, and let boil for 5 minutes.
Stir grains well when adding.
Let simmmer ten minutes after boiling.
Settle with a dash of water or let stand a few minutes.