Initially, blast chillers and blast freezers were mere refrigeration units. Thanks to technological advances, they are also performing cooking functions today. Even quite a few compact units offer this possibility. This means that even operators of smaller kitchens can use cook & chill – a big chance to respond to changes flexibly. by Dieter Mailänder, Redaktionsbüro Dieter Mailänder
There is one thing we can all assume: Our future will be different than the past. Europe is also feeling this wind of change in many ways – socially, economically, politically, in terms of the environment and more. It is not equally strong everywhere, but very clear everywhere – even in the out-of-home market. Some of it segments are changing significantly right now. Below, you can find two examples of this.
Fortunately, the number of visitors in the retail trade returned to normal after the pandemic. Nevertheless in 2022/2023, the share of private consumer spending in the 27 EU countries in comparison to 2021 fell by 4.6% to just over 34%. One can assume that this development has also left its mark in commercial gastronomy.
The consumers must build up relatively high reserves for their energy bills due to the Russian war of aggression and must put up with noticeably higher costs for almost all consumer goods. Both factors reduce the part of the disposable income available to them for eating out. As a result, the frequency of visits and demands there are changing, and the chefs must adjust their offers and production accordingly. A second example: Work from home (WFH).
A study by the European Central Bank (ECB) during the time of the COVID-19 pandemic shows an interesting development. Before the pandemic, around 60% of the respondents worked on-site at their usual place of work, 20% worked remotely for up to one day, and 10% for two to four days; some also had five or more WFH days. After the pandemic, only a good 30% worked on-site; all the others used the possibility to work between one and five or more days from home. Therefore, the meaning of working remotely has changed completely.
This development is reinforced by the fact that employers are reducing the number of their workplaces in office buildings. Those who occasionally work on-site must register and are assigned to a workstation. How does this development affect canteens? Chefs reported that, compared to pre-Corona times, the number of stationary meals served has fallen dramatically in many cases, so that on some days there was temporarily no production at all. They reacted very quickly to this and developed new sales channels to stabilize their production.
Some offer, for example, take-away and /or meals to be delivered to the home office. Others have developed offers for those who work evenings or nights on-site around the clock. Due to this change in demand, they have often had to make major changes to their production. Time shifted production, blast chilling and flash freezing were some of the ways to be able to meet this need. The prerequisite: flexible equipment. That’s why they invested in smaller, multifunctional devices, especially in modern blast chillers and freezers that can also take on thermal functions. This is how they noticeably increased the flexibility of their operations.
Why can a Blast Freezer also Cook?
It is not uncommon for a device to assume inverse functions in refrigeration technology. For example, certain heat pumps can both extract and supply heat to the outside air. How does it work? They extract heat from the outside air, make it usable for heating and hot water in several steps and feed it into a house’s circulation system, thus heating up its rooms. On the other hand, they can extract indoor air from these rooms and release it into the outside air to cool the inside of the house.
-40 to +85 ° C
Some refrigeration equipment can also perform inverse tasks. During blast chilling or flash freezing, energy is extracted from the cooked food and is lead into the heat exchanger. This is filled with a low-temperature gas that absorbs the energy of the food, so it is cooled. Innovative manufacturers are increasingly using R290 (propane) for this. This gas is considered environmentally friendly because it has, for example, a low global warming potential and it doesn’t harm the ozone layer in the atmosphere.
Quite obviously, it wasn’t easy to refine the technology of the evaporator so that this medium can be used. But that is not all. The temperature range of high-quality blast chillers/blast freezers ranges from minus 40 °C to plus 85 ° C. Being that they can also take over cooking functions. So, they offer chefs a wide range of applications. It ranges from flash freezing to pasteurization, which means that they can also cook at low temperatures (low temperature cooking).
Professional cooks use this method with pleasure when roasting substances are supposed to form slowly on meat or other food to be cooked (the Maillard reaction), whose aroma gradually migrates into the interior. This process, which usually takes several hours, runs at a temperature of up to 80 °C and keeps the core temperature below 70 °C. It makes sense to use the night hours with their often-lower tariffs for this. Additional advantage: The responsible parties utilize their blast chillers/blast freezers at a time when production is at a standstill.
Cook & Chill – Everyday Technology
For a good 40 years, cook & chill has been establishing itself on the market at an increasing speed. At the beginning, the investments in thermal devices, blast chillers/freezers, cold storage cells, and deep freeze cells as well as in the equipment for food distribution (especially important for hospitals) were very high. The few operations that were able to finance and set up the necessary hygiene management (the range between +65 and +3 °C is particularly sensitive) at that time worked according to a completely different workflow than conventional kitchens – there were no combined systems. This constellation has completely changed.
Today, chefs use different cooking methods with their smaller, more flexible devices from cook& serve by way of cook & chill up to cook & freeze in parallel – as needed.
Cook & Chill – Two Technologies
Liquid or pasty food products like sauces, soups, purees, or many desserts from puddings to creams have a high density and need a lot of time to cool down to 3 °C. Unwanted skin forms relatively quickly on such foods. If one uses a stirring kettle for the rapid cooling, in which the goods to be cooled are stirred during the cooling process, this procedure runs smoother and faster without forming a skin in comparison to blast chillers.
For culinary reasons, pan-fried dishes must not be mixed after the cooking process. For casseroles, gratins, fish, or meat, it is technically no longer possible. Blast chilling by air circulation in the chiller is the means of choice for them. In this process, the heat is extracted via the surface of the food.
The Challenge for the Future
IT savvy chefs want to integrate all their devices into networks in order to monitor, document, and evaluate important parameters such as energy consumption or temperature profiles closely. It is currently not uncommon for them to have to settle for suboptimal solutions because manufacturers and cloud service providers have not yet succeeded in implementing a compatible standard for all devices. Of course, this is a demanding and complex task – after all, it involves data that must not fall into the hands of competitors. On the other hand, the demand is becoming louder for network-driven cloud solutions and not just in recent times but for at least ten years. The industry is waiting, there is a lot to do, and it remains exciting.