In the case of resource efficiency, many kitchen professionals think about energy costs or consumable materials like cleaning agents. This is quite understandable. But it is of similar importance to retain the resources of food optimally: for example, with the cooking technique cook & chill.
By Dieter Mailander
Cook & serve is the popular form to cook and serve dishes – at the work place, in schools, universities, hospitals, and nursing homes or in any type of restaurant. But if they are kept hot several hours before or during serving, the nutrient content decreases, the consistence dissipates, the moisture evaporates, the colors fade, and flavor carrier wanes. In these cases, and if there are high requirements for freshness, other technologies present themselves in order to meet the complex requirements. One alternative is to decouple meal production from distribution; dishes will be cooked and blast chilled from cooking temperatures down to 3° C as quickly as possible and served within three days.
Culinary Excellence, Efficient, and Resource-Saving
According to the observation of experts, this cook & chill method is being asserted increasingly. It was developed in the USA. Swedish cooks, in particular, have refined it. In the 1980’s, the first cook & chill kitchens sprung up in Central Europe and served significantly more than 1500 meals a day; 20 years later 500 meals could already be cooked economically. That’s why today the method is firmly established in schools, nursing homes, or food courts of large super markets too.
Using Cooking Methods in Parallel
Chefs, who are cooking for a heterogeneous target group, use different methods. If they are serving dishes shortly after their production, cook & serve is frequently the most cost-effective solution – their calculation is not burdened by the high costs of refrigeration technology (see below).
Dishes with longer waiting or distribution times are culinary and hygienically dangerous up to high-risk, for example, because they can produce dangerous toxins. That’s why they have to be eliminated after some time: in Germany after three hours. For the production of such dishes, cooks often use cook & chill. After preparation, the meal is divided into portions in cold rooms at c. 12° C and distributed cooled. On the stations of the hospitals or in living groups of nursing homes, it will be regenerated and served immediately. In this way, every patient or resident can enjoy his meal hot and (hopefully) won’t have to give back any leftovers, which land in the wet waste garbage can.
The Advantages of Time-Shifted Production
Cook & chill offer many advantages. We will name some of them in an exemplary manner.
By blast chilling and shock freezing, cellular structures of the dishes remain intact and therefore their taste, color and consistence are kept for the most part. If the dishes are served shortly after regeneration, guests, patients, and residents are able to enjoy them in a high quality – an invaluable advantage for the acceptance of the cooking.
The metabolism of sick, old, and young people requires not only an appropriate diet, but also a high degree of safety. Whoever cooks for these target groups, has to work especially careful hygienically, in particular with regard to temperature control. Substances (microorganisms), which are critical for people, grow between 65° und 10° C with an enormous dynamic. That’s why the process times have to be minimized during this extremely sensitive phase. High-performance units cool dishes from cooking temperatures down to 3° C in 90 minutes (even when freshly cooked food has to be pushed in repeatedly during running cooling cycles). Based on the assumption that all of the components of the unit are optimally coordinated with each other, power peaks can be coped with easily. Furthermore, they should have systems at their command, which sterilizes the air in the units.
Flexible Purchasing Arrangements
If the cooked components are shock-frozen directly after cooking, one can store them at least six to nine months without any problems. This is how one can make use of special offers and avoid high purchasing prices.
Efficient Employee Utilization
In classically organized kitchens there are always idle times, but peak periods too, with which not every employee can cope with well. With cook & chill, the kitchen chefs are able to plan their work processes relative precisely and utilize their team continuously.
In multifunctional devices, the kitchen professionals are able to blast chill, shock freeze, cook, defrost, regenerate, pasteurize, and cook resp. bake at lower temperatures.
The Requirements for a Time-Shifted Production
Cook & chill kitchens require large investments in blast chillers/shock freezers, central stockrooms, often even decentralized refrigerators, cooled portioning spaces/ conveyers and active or passive refrigerated distribution trolleys. A lower six-digit figure accrues quickly, which can be financed in different ways (purchasing from the cash flow, installment purchase, leasing, etc.). To assess these alternatives realistically is one of the high demands on the control of the commercial kitchen. Another task of particular relevance is the calculation of the amortization. In addition to the costs of the acquisition, those of the operation (energy, refrigerants, etc.) have to be considered and namely completely and throughout the entire operational life (full cost accounting).
Cook & chill requires a different kind of production flow than cook & serve. Therefore, this calculation is a particular challenge. The work organization has to often be newly developed and verified with budget costs. At the same time, the kitchen management, control, and if necessary the kitchen specialist planner have to work together closely in the process.
The Cooling Chain
Apart from a few exceptions (portioning, special situations of the transportation), the temperature during the entire cook & chill cooling chain has to be at 3° C or below – at least in Germany. In the other countries in the EU, there are possibly other regulations.
Check the Information from Manufacturers
It has stood the test of time to check the technical data of the equipment manufacturer in comparative field tests in your own operations on the basis of neutral performance criteria. Important parameters are the beginning of the cooling process, the performance of the condenser, the temperature of the vaporization, as well as the cool-down period. Of course, all of the testing devices have to be tested under identical conditions (for instance GN 1/1-65, rice at cooking temperature, 3.5 kg net weight), otherwise the findings will be distorted.
Coordination Between the Chiller and the Cooling Unit
The necessary service is only rendered, when the blast chiller and cooling unit are coordinated to each other optimally. In order to avoid difficult discussions with suppliers, experts recommend, that the manufacturer of the blast chiller deliver the refrigeration technology too. Cook & chill is a method with which kitchen professionals are able to retain the both most important resources of their food, culinary art and nutritional values, optimally. They optimize their production processes, reduce the strain on the staff, and increase the output of their production. The investments are relatively high, but they amortize themselves during the operational life.