Potato Crisps - Homemade Potato Crisps – and Types of Ovens for Making Potato Crisps

In British English, a potato crisp is a thin slice of potato that is deep fried or baked until crunchy. In British English, the so called “French fries” which are thick potato wedges is what is referred to as chips in Great Britain and Ireland. Different countries have varying definitions between chips and crisps. Potato crisps are a part of the snack food and are liked and consumed by the young and old in many countries. In this article, the subject is about how to make the crunchy slices of baked potatoes - crisps.

To make good quality crisps, you will need quality potatoes, vegetable oils, flavorings, and good techniques on how to make the crisps. You will also need a good oven which you can manipulate, especially the temperatures, to achieve the desired results. There are many types of ovens and at home, you may use a Microwave Oven, Conventional Oven, Convection Oven, or Oven Toaster Grill (OTG).

A microwave oven cooks or heats food by dielectric heating. Microwaves are invisible electro-magnetic waves which are similar to radio and television waves, infrared radiation, visible light or ultraviolet rays. The energy in microwave causes molecules in food to rub against each other, producing heat. It’s the speed of movement of molecules in food that determines the temperature. The vibration of food molecules in a microwave oven can vibrate at about 2.5 billion times per second. In a microwave, heat is generated simultaneously on the outside and in the deeper layers of food. The frequency at which microwaves cook has properties of the radio waves being easily absorbed water, fats and sugars whilst the same radio waves are not easily absorbed by most plastics, glass or ceramics. Metal plates are not ideal to use in microwaves as metals do reflect microwaves.

About 90 percent of homes in America have microwave ovens. During the cold war period, the Russians banned the use of microwave ovens on the basis that electro-magnetic-field hazards from microwave ovens can cause health effects on humans – effects such as feelings of anxiety, headaches, leukemia, etc. The mainstream science does not support this and after the cold war, the Russian are again using microwave ovens just like anybody else.

A conventional oven is a kitchen appliance usually fueled by gas or electricity and used for roasting, baking and heating. In a conventional oven, heat from the filament or burner radiates up and the heavier cold air in the upper component is pushed downward by the lighter hot air. This is repeated again and again as heat is distributed all over the components of the oven. In a conventional oven, there are no fans to circulate the hot air resulting in some areas of the oven cavity being hotter than others. This results in uneven cooking, heating or baking.

A convection oven is just like a conventional oven only that it has a fan inside the oven cavity that pumps the hot air throughout the oven cavity. It is this pumping of hot air that accelerates the movement of heat by convection. The fans ensure there is a uniform distribution of heat in the oven for faster and even cooking, heating or baking. If you are one of those who like baking, then, you most likely have a convection oven.

Oven toaster grillers (OTG) are small toaster ovens which are usually used to toast or cook small amounts of food. OTGs are not well insulated like regular ovens but they heat very fast. They have heating elements on sides of the oven cavity. The oven toaster grillers cook by adding direct heat to food. As it is small, the oven toaster griller usually has a lower price relative to other type of ovens.

There are many types of potatoes such as the Russet Potatoes, Round White Potatoes, Long White Potatoes, Red Potatoes, Yellow Potatoes, Blue and Purple Potatoes, Fingerlings, etc. The variety of potatoes that are mostly used for making potato crisps include the following: Maris Piper, King Edwards, Rooster, Sante, Pentland Dell, Lady Rosetta, Lady Clare, etc, etc.

A potato will most likely have an oval shape with a length of about 4 inches and a radius of 1 inch. If we were to make 1/16 inch thick slices out the potato, we would have 64 slices and each slice would have a top-face surface area of 3.14 inches squared. For 64 slices, the total top-face surface area would be about 200 inches squared. To slice potatoes, use a mandolin slicing tool.

Next take the dimension of a plate that you would use inside the cavity of your oven. Let say the plate has the dimensions 12” x 8” which would give you a top-face surface area of about 96 inches squared. If we allow only a slight overlap of the potato slices in the open cavity, then a plate can only hold slices from just one potato.

From the above, we can have an idea that trying to make your own crisps at home is not very economical and it would be more sensible to buy ready made crisps from your food store. However, if you must make your own crisps for fun or recreation, then, you would have to ignore the cost of energy and the time consumed in making crisps using home ovens.

The trick to successful crisp making is based on controlling the water content of the potatoes. If there is too much water in your potato slices, you ending up steaming your crisps instead of frying dry. If too many potato slices overlap each other, then, they result in steam cooking instead of dry frying. And then there is the issue of the potato slices sticking on the pan/slack.

Household Aluminium Foil is a thin leave of aluminium with a thickiness of less than 0.024 millimetres. A household aluminium foil is used to wrap food in a grill or oven to prevent loss of moisture that may result in a less appealing texture. Aluminium foil is usually used for barbecuing. An aluminium foil has almost a nil porosity – no ability to absorb water.

Household Greaseproof Paper is paper that is impermeable to oil or grease and is usually used in cooking. A greaseproof paper has a very low porosity – very low ability to absorb water.

Parchment Paper and Bakery Release Paper - these are papers used in baking and provide a non-stick surface. These papers have the capability to withstand the temperatures involved in the baking and roasting process without burning. Parchment paper and bakery release paper are somewhat porous and will allow water to penetrate through the fine pores of the paper. The fact that the paper is a non-stick surface and the fact that it allows water to penetrate through the fine pores makes parchment paper the ideal surface for dry crisping without steaming.

Though leaching of potato slices with hot water is used to tie up the sugars and hinder the sugars in the browning reaction, leaching of potatoes in cold water is absolute minimum that is necessary so that some starches in the slices can leech out into the water. The starches that leach out would otherwise have participated in preventing water from escaping out of the potato slices. To leach out the excessive starches in the potato slices, you just need to soak the slices in water for 1 – 2 hours and then remove the slices from water and dry them by wrapping in a piece of cloth for a few minutes

Maillard reaction is actually what is called browning reaction. When glucose and glycine in potato slices is extracted by dipping the slices in hot water (65°-95°C) for 1 - 2 minutes, the resulting crisps are white without any browning. The browning you get in fried potato crisps is due to Maillard reaction which is determined by the amount of reducing sugars on the surface of slices plus the temperature of frying and the frying period. Maillard reaction is unfortunately the pathway for acrylamide formation in potato chips and crisps.

Fried crisps and chips can have a very high concentration of acrylamide – about 420 micrograms per kilogram of chips and about 1700 micrograms per kilogram of crisps. Acrylamide is known to cause cancer in rats (but so far no evidence for the same in humans). To overcome the browning reaction for acrylamide formation in potato chips and crisps, it’s highly recommended you soak the potato slices in water for 1 – 2 hours before frying them. Better still, you can do a 1 – 2 minutes hot water extraction to your potato slices before frying them.

The frying temperatures for potato crisps are 160°C - 185°C for a period of 3 minutes. This can vary up to 5 minutes depending on the cavity atmosphere of your oven. Experiment until you find the appropriate frying time for your oven. Pause briefly for 30 seconds at the exit temperature of about 164°C if you are interested in the gold-ness colour to form in your crisps.

Having come this far, we can now list the steps you need to follow to make good crisps:

1. Select your oven. It can be a microwave oven, conventional oven, convection oven, or oven toaster grill. The ovens that have the ability to control temperature to the accuracy of 1˚C are even better.
2. Select your potatoes. It can be Maris Piper, King Edwards, Rooster, Sante, Pentland Dell, Lady Rosetta, Lady Clare, etc, etc.
3. Peel and wash the potatoes
4. By use of mandolin, slice the potatoes into slices with a width of about 1/16 inches (1.5 mm)
5. Soak the potato slices in water for 1 – 2 hours to remove excess starch that hiders the escape of moisture/water from the slices. Better still, dip your potato slices in slices in hot water (65°-95°C) for 1 - 2 minutes to extract starch/glucose and glycine so that your fried crisps will be white with very little browning. Too much browning has lots of Acrylamide which is known to cause cancer in rats.
6. Dry the water soaked potato slices with a piece of cloth
7. Put the dried potato slices in a container. Add just a little of your favorite limpid oils such as cottonseed, corn, peanut, olive, etc. Add appropriate quantity of salt, spices, and your flavoring ingredients. Shake appropriately so that ever slice gets the appropriate amount of oil, salt and spices. You need to be very careful not to add lots of oil.
8. Cover the bottom rack of your oven with a Parchment paper. Parchment paper has a non-stick surface and will allow water from the surface of the potato slices to escape so that chances of steaming are reduced.
9. Spread the potato slices on the parchment paper such that there is very little overlapping and overcrowding in the cavity of the oven. Anything that can create too moist atmosphere in the cavity of the oven should be avoided.
10. Close the oven door and fire the oven at 170°C - 190°C for a period of 3 minutes. After 3 minutes, your crisps should be ready. The firing period can vary up to 5 minutes depending on the cavity atmosphere of your oven. Experiment until you find the appropriate frying time for your oven. At the exit, pause briefly for 30 seconds at the exit temperature of about 164°C if you are interested in a gold colour forming in your crisps.

And a day will come when you will make one plate of good crisps which are not soggy but crispier. The biggest question you will be asking yourself is whether it’s worth the effort to do all-that work just to make only one plate of crisps.

In as long as you can make that one plate of good crisps, the creativity in you will inspire you to maneuver your oven(s) in an economical way such that sooner you will be making enough crisps to feed your family in a very short time. In fact, you may end up expanding your potato crisps making into a home based business where you will be selling your potato crisps to your neighborhood at workable prices.