Globes, consisting of two hemispheres, made of cast-iron and so arranged that they opened to fill and discharge, but operated substantially as above, only with the method of lowering into the fire changed somewhat, I have seen in use in Scotland in 1840. They were called French roasters.
In this country a few years ago the use of the long sheet-iron cylinder was almost universal, varying only in the method of placing the cylinder over the fire—some sideways on a track, others endwise, sliding on a long shaft or by turning on a crane, in either case causing considerable labor and loss of time, which often resulted in the hands of the inexperienced in more or less spoiling the batch of coffee.
From his expert knowledge of coffee and coffee-roasting problems, Jabez Burns quickly rose to a commanding position in the industry. He was a trade teacher and a trade builder. He had very definite ideas on roasting. He said:
The object of roasting is not attained until all the moisture (water of vegetation) is driven off. Roast properly—uniformly and sufficiently—and you will get all the aroma there is in the bean. Coffees of various kinds can not be roasted to a uniform color. Some will be of a light shade when sufficiently roasted while others will have to be roasted dark to develop the aroma. Therefore, appearance alone is not a proper test. Aroma-saving devices have had their day. Coffee is of no use unless the aroma is fully developed, and the more it is developed by roasting the better it is. What passes off in the roasting process can not be saved and is so small that if all of it in the country could be collected and freed of all foreign matter, it would not weigh an ounce.
Roast coffee over a slow fire so that it will be an hour before it has the color of roasted coffee, and, in contrast, produce in another batch of like quantity the same color in thirty minutes, and it will be found for all intended purposes, either to grind, sell or drink, that the latter will be, beyond all comparison, the best. Coffee should be roasted uniform and as quickly as possible, only it must not be scorched or spotted, otherwise it will have a bitter burned taste. If roasted properly it will very considerably increase its bulk and will be plump, swelled out and crisp; easily crushed in the hand or between the fingers.
In his Spice Mill Companion, published in 1879, Jabez Burns said further in regard to roasting:
All coffees do not roast alike; some will be a bright light color when done, and others will be dark before done. There are two infallible rules, which if properly appreciated and tried will prove to be practically useful. One is, when the aroma is sufficiently developed to produce a sharp, cutting, but aromatic sensation in the nose. Those who practice that way do not need to see the roast. The other rule is that when a berry is broken it is crisp and uniform in color inside and out. Those who are accustomed to this method may be good coffee roasters, albeit they may not have any nose at all. But we must state in this connection, that a man who has no smell and is color blind is not a fit candidate for the coffee roasting profession; and, moreover, we affirm that any person who can not roast coffee, so far as judgment is concerned, after a few trials, will never make a good operator.
Burns Granulating Mill, 1872–74