This section is from the book "The Potato: A Compilation of Information from Every Available Source", by Eugene H. Grubb, W. S. Guilford. Also available from Amazon: The Potato: A Compilation Of Information From Every Available Source.
It is difficult to set an exact value on the potato used in the potato-flour industry. Some factories buy them by the hectolitre (2.837 bushels) without paying any attention to the quality, while others grade them according to the amount of starch contained. However, it is estimated that at an average of $0.34 per hectolitre the value of potatoes ground into flour in one season would be $3,400,000. Calculating roughly, one hectolitre of potatoes produces eleven kilos of flour (8.54 pounds to the bushel). A conservative estimate of the total production of potato flour in the Netherlands for one season is 110,000 metric tons of 2,204.6 pounds. The price per bag of 100 kilos (220.46 pounds) has varied in the last few years from $3.60 to $5.20. An average price of $4.40 per bag would bring the total value of the manufactured product up to $4,840,000 per season, $1,440,000 more than the cost of the raw potatoes.
It would seem bad business for farmers to pay a rent of $122.50 per acre, fertilize to the extent of $10 or $15, and sell 380 bushels of potatoes per acre at $0.12 to $0.15 per bushel, but it should be understood that the most valuable land, highly fertilized, produces much more than the average. 'The potato flour exported from the Netherlands goes to Great Britain, Spain, Belgium, Italy, the free port of Hamburg, Denmark, and the United States and Canada. The United States imported $38,000 worth of dextrin and potato flour from the Netherlands in 1910. England and Belgium are perhaps the best customers. Exports have grown from 35,933 metric tons in 1898 to 64,000 tons in 1909.
There are altogether thirty-two potato-flour factories in the Netherlands, of which twenty-four are in the Province of Groningen, two in Fries-land, four in Drenthe, and two in Overyssel. In addition to this there are several small factories producing only dextrin or glucose. The total number of men employed in the works is nearly 3,000. Most of the factories are situated on deep canals in the reclaimed swamps of the Veenko-lonien, and the tubers are transferred from the boats direct to the mill.
A disagreeable feature of the potato-flour industry in the Veenkolonien is the waste thrown off and the consequent pollution of the canal water. Just after the milling season the water is so bad that ignitible gases evaporate from it. Often a lighted match thrown into the canal will cause an apparent blaze. The economic loss resulting from this waste is in the eyes of the planters of that region a serious matter. In all it is estimated that the wasted material is worth $666,432 per year.
In connection with the potato-flour industry there are seven dextrin factories in the northern part of the country and two in the province of Limburg. Dextrin is used chiefly for sizing purposes in textile plants. As a consequence, the demand for that product depends largely upon the cotton and linen industries. While there is a flourishing cotton industry in Overyssel, it is not sufficient to consume all the dextrin produced here, the remainder being shipped to Great Britain, United States, Spain, Italy, and Belgium. However, the exports in this line have decreased of late years, owing to both the increased price of the dextrin and higher import duties in many foreign countries.
The production of glucose from potatoes in the Netherlands dates from 1875, since which time it has not only greatly increased but the quality has been improved. Eleven factories, some combined with potato-flour establishments and others working independently, produce glucose from potatoes in both the solid and liquid state. From a total production of 9,600 metric tons in 1896 it has grown to 20,000 tons in 1908. Almost all of this glucose is consumed in the Netherlands, especially in confectioneries and cake and jam factories. It is impossible to build up an export trade in this article, owing to the high import duties in other countries and the strong competition it encounters especially from American glucose manufactured from corn. There is a constant fear of overproduction in this article. However, the confectionery industry in the Netherlands is so thriving that domestic consumption may keep pace with the supply for a long time. The high excise tax on the article when consumed in the country - 3.28 cents per pound, American currency - is a great bar to its use. The form in which it will find its most successful outlet, therefore, is in a manufactured state, such as cookies, candies, and other confectioneries, as the excise is withdrawn from such articles if actually exported to another country. It is evidently exported in that form."
Intensive cultivation" is the lesson to be learned from the European potato grower.