history - food : potatoes

Potatoes

The Incas survived on it, the Scots banned it on religious grounds, a French Queen wore its flower in her hair and the Peruvians enjoy 4,000 different varieties. Call it the humble spud or just plain potato, there is nothing plain or humble about it. We take potatoes so much for granted as a staple that it seems incredible that there was a time when even starving people refused to eat them, believing they caused leprosy. This is not as far-fetched as it seems, explains Waverley Root in his encyclopaedia, "Food". Potatoes are members of the Solanaceae family, which includes deadly nightshade. The green colour in potatoes exposed to light betrays the presence of solanine, which is poisonous. Modern potatoes do not come in a high enough proportion of solanine to cause real harm, but the potatoes of the 16th and 17th centuries contained higher dosages - not enough to kill, but enough to cause the skin to break out in a rash.

Research centre

In Lima, Peru there is an international based potato centre; where research work is undertaken and new varieties bred. Such varieties with unpronounceable names as; Ilunchuywaqachi, solanum bukasovii and mishipasingham ! The scientists at the centre main aim is to increase the output in the poor, developing countries where the potato is an ideal shield against famine and malnutrition. The centre has 600 staff with an annual budget of $NZ 35 million, and concentrate on maintaining a gene bank and developing new strains resistant to pests and disease. In one of the quiet corners is the world renowned potato hunter; Carlos Ochoa, justifiably called the Indiana Jones of the potato. Turning his back on the comforts of family and city life, the 75 year old has tramped through South America for the last forty years in search of the perfect potato. In this time he has frequently had to brave bandits, guerrilla's and freezing temperatures , but has also discovered 80 new wild potato species.

Why all this in Peru? Well the humble tuber has gained mythical status there; special visitors are honoured with a meal of sweet yellow potatoes, the faithful leave their prize specimens on mountain tops as an offering to the Gods, Doctors prescribe potato juice as a remedy for gall stones, would be wives are made to peel the knobbly lunchuywaqachi (Quechuan Indian for "the potato that makes young brides weep") in a ritual test of domestic skills, said to cement their relations with their future mother in law. Potatoes are to the Peruvian's what wine is to the French and tea to the English.

In Mexico there is even a museum dedicated to food and the potato, information on this can be obtained over the internet at:

• Food museum
• Food museum - potato

THE BEST POTATO FOR THE JOB

Many people, experienced Chefs included, often complain that the potato doesn't mash properly or falls apart when the they try to roast them. There is a very good reason for this; different potatoes have different properties to them. Some are good for roasting , while others are only good for boiling and others for mashing etc.

Why is this?

Basically because of their moisture (water) content or another way to look at it is their solid matter content. A potato low in solid content (high in water) will be a good masher but a poor fryer, whereas a potato high in solid content (low in moisture) makes an excellent fryer or roasting potato. If a good boiling potato is required a medium to high solid content is required

The way to tell this is to purchase only certain types of potatoes for certain jobs, because different varieties have been 'bred' with different water content. The proceeding table will show this. The time the potato is grown and harvested will also effect its moisture content; a potato grown and harvested during a drought (no matter what the type) will no doubt have a fairly low moisture content. Similarly, even the varieties grown for their high solid content will probably have a high moisture content if grown and harvested during extreme rains.

A simple test that can be done is to test the potatoes density (or specific gravity):

• Dissolve 1kg salt in 8 litres of water ( 20° C )
• Put some potatoes in the water
• Any that float will make good frying, roasting or boiling potatoes
• Those that sink will probably cook up floury and best left for mashing

For information about different potatoes and their properties <click here>

Storing potatoes

Although potatoes feel hard to the touch and look tough, they are as easy to bruise as apples.

Take a good look at potatoes before you buy, and refuse any damaged potatoes.
Store potatoes in a cool, dark, dry place; exposure to light will turn them green and warmth will encourage sprouting.

Do not refrigerate them or leave them to sweat in plastic bags.

Kumera (new Zealand sweet potato)

The sweet-potato crop has a large potential for development since a worldwide increase in sweet-potato research has improved our understanding of this crop's requirements. In New Zealand we know the crop by the name kumara, however, internationally it is called sweet potato, with the botanical name: IPOMOEA BATATAS.

Sweet potatoes are generally planted from mid October and harvested up until April. A light, loamy soil is recommended for growing sweet potatoes, with a pH of 5-7. Fertiliser is broadcast at 1 t/ha of 30% potassic super or its equivalent. Planting is into ridged soil using mechanical planters with 25-30 cm inter-plant spacing. Weed control is by cultivation or low rates of paraquat. Climate is very important because sweet potato is a tropical crop. High temperatures are required to achieve good yields, while cool, wet conditions prior to harvest may cause rotting. Harvesting is performed using a modified potato digger. Care must be taken not to damage roots with moving parts or by dropping them from a height. The harvested roots must be cured at high temperature and humidity for several days before long term storage at 15°C and 80% humidity. High humidity helps to reduce shrinkage caused by water loss.

Markets

A large amount of sweet-potato is grown worldwide, with China alone consuming 93,550,000 tonnes annually. Almost all of New Zealand's current production, about 16,000 tonnes per year, grown in Northland and along the North Islands East Coast, is sold on the fresh local market. Increased international research has focused on developing processed sweet-potato products. Potential processed products include French fries, crisps, flour, baby food, puree and other canned, frozen and dehydrated products. Sweet potatoes with potential for processing are being evaluated in New Zealand.

The information contained here is supplied for your interest only and further research may be required. I have gathered it from many sources over many years. While I attempt to insure they are crossed referenced for accuracy, I take no responsibility for mistakes - additions or corrections are welcomed.

email chef@tallyrand.info