Frequent fryers
Frozen and chilled chips have improved significantly in quality over the past few years, due largely to improvements in potato growing and storing at farm level and to advances in quality control in manufacture.
The incidence of unsightly black blemishes, green tinges and badly cut, broken chips is largely a thing of the past, and although there is still a lot of quality variation in what arrives on the customer's plate, it is far more likely to be a result of operator error in the kitchen than the fault of the manufacturer.
This is the view of McCain's food service technical support manager, Anne Sonley, who says that some caterers are not effectively managing the profit potential from chips by not properly storing and frying frozen chips. Sonley says that care with frozen chips begins at the goods-in stage, with receipt and delivery procedures that ensure cases of frozen chips have arrived from the food distributor still frozen and are put into cold store immediately, not left on a doorstep waiting for someone to find the time to put them away. Chips that have slightly thawed then been frozen again will stick together in clumps.
One of the recent advances in ready-prepared chip production has been in the choice of how the caterer buys them. While frozen chips have long dominated the prepared chip market, chilled chips are growing in popularity. Where there is a consistent and predictable high turnover, using a chilled product saves on storage costs, since it can be held in a fridge at 6-8°C rather than in a freezer operating at -18°C. This also leads to lower energy costs on frying, as less energy is needed to keep the oil at a chip-frying temperature of 180°C with a chilled product than with a frozen one.
Speciality chips, with coatings and flavours, remain a small part of the market, but they do allow caterers to offer a second fried potato product on the menu. Lamb Weston's latest speciality chip is possibly the most novel yet - the company is producing curry-flavoured chips in the form of skin-on wedges that will fry or oven bake.
From freezer to oven Oven baking of frozen chips is a relatively new development, and is possible because there is enough fat on the outside of the chip after factory par-frying and freezing for the crisping process to happen. Combi-oven manufacturer Rational even produces a special gastronorm chip basket for oven baking.
The health and obesity issue surround excessive chip consumption is not just a concern for those involved in school meals, but for others with a captive market, such as staff restaurants. The answer from McCain has been to produce McCain Lights, claimed to contain 33% less fat than typical catering chips after deep-fat frying.
Just as there have been advances in the chips themselves, so too in the oil in which they are fried. Beef tallow, traditionally used in the fish-and-chip shop sector, mostly in the north of England, is losing ground to solid vegetable oil, usually palm oil. The vegetarian issue of frying in animal fat is the main driver of the switch away from tallow, but while palm oil resolves the vegetarian issue and is a very robust oil, it is still extremely high in saturated fat, at about 50%.
In the general catering market, two types of oil are used. The cheaper is standard blended vegetable oil, usually produced from rapeseed or rapeseed blended with soya oil. The other is long, or extended life, oil which has been further refined.
Alan Preston, commercial director for Anglia Oils, whose main chip oil is the Prep brand, warns that blended oils using soya can be a trap for the unwary caterer. He says: "We no longer use any soya oil because more than likely it has been produced from genetically modified seed, and that's an issue for a lot of people."
Standard cooking oils have a 70% market share in UK catering, not least because of their cheapness. But the purchase price may not reflect the real cost. Preston explains: "We wanted to make an easy cost comparison possible, so we developed what we call the Chipometer, which is a marketing explanation of oil and how to calculate the real cost." The chart for this is shown on Anglia frying oils packaging and gives the expected frying life of all the types of oils, expressed in chip-frying hours, before they reach disposal point. Evaluating purchase price against frying output and life gives the actual cost of the oil.
Anglia says that a standard cheap, own-label blended vegetable oil, when used to fry chips, would last no more than three hours. Using an extended-life oil for the same purpose will yield a working life of four hours. The top-of-the-range Anglia Prep Maxi oil is said to last for nine hours of chip-frying time.
However, the lifespan of oil is greatly affected by what is being fried. Chips are probably the most benign food for oil damage, while meat products are the worst, as animal proteins cause rapid breakdown of the oil structure. Food items such as chicken nuggets can break down a cheap oil in one service period.
For many chefs, the test of when to change an oil is a visual one. If it is smoking and discoloured, with the chips taking on a bitter flavour, then it is time to change. But that visual test is outdated, according to Bob Witherall, general manager of fryer supplier Valentine - as is checking to see whether the bottom of the fry basket is visible when it is in the oil. "You can be throwing away oil that is still good, or cooking with oil that is so degraded it spoils the food," he says.
Valentine sells a stand-alone oil tester costing less than £100 that measures the amount of chemical debris in the oil. A sample of oil is put into the unit, heated to operating temperature then tested using a litmus paper. The kitchen can then be told whether the oil is still usable or needs to be changed.
Another important aid to maintaining the quality of chips and the oil they are fried in is proper cleaning of the oil. Particle deposits from food left in oil will quickly carbonise and break down the oil. With this in mind, Fri Fri, part of Swiss equipment manufacturer Franke, has developed an optional extra for its fryers which is able to pump out and filter oil while it is at its 180°C operating temperature. The oil is filtered twice, with the start of the second filtration also flushing out debris in the cool zone collection area in the base of the tank.
What makes a good, fresh chip?
Once they are cooked, different varieties of potatoes have different textures, owing to changes in the cellular structure of the potato during cooking. Waxy potatoes are firmer and hold their shape as a chip, while floury potatoes are softer, break up and absorb more oil.
The best chipping potatoes are Cara, Wilja, Maris Peer and Desiree. Avoid soft potatoes such as King Edward and Pentland Dell.
The traditional double-cook blanching method for chips is recommended for cooking chips from fresh potatoes. Fry the chips for five minutes at 190°C, drain and allow to cool. To finish to order, crisp at an oil temperature of 200°C. This will deliver a chip that is soft on the inside, crisp on the outside.
Contacts
Anglia Oils
01482 701271
Fri Fri fryers 01708 683636
Lamb Weston
01489 565826
McCain 01904 486666
Valentine
01189 571344
