In roasting, good coffee swells about thirty-three per cent., and loses about sixteen per cent. in weight.
Roast once a week or oftener.
Put coffee in the apparatus (cylinder, or drum, or roaster), the quantity to be according to the size of the roaster, or according to how much is needed. Have a rather slow fire at first; when the coffee has swollen, augment the fire, turning, shaking, tossing the roaster, sometimes fast, sometimes slowly, and take from the fire a little before it is roasted enough; the roasting will be finished before the coffee gets cold and before taking it from the roaster, which you continue turning and shaking as if it were yet on the fire.
A charcoal fire is the handiest, and more easily regulated.
It is well roasted when it evaporates a pleasing odor and when of a brownish color.
Then take it from the roaster, spread it on a matting or on a piece of cloth, and put it in a tin-box as soon as cold.
It is exceedingly difficult, if not utterly impossible, to roast coffee properly by machinery, and for two reasons: in the first place, there is too much of it in the cylinder to roast evenly, some berries are burned, others not roasted enough; the other is, that being turned by machinery, the cylinder is turned regularly and is neither shaken nor tossed; and even if there were not too much coffee in it, some berries would be much more roasted than others.