Ebersberg just outside of Munich. A rural idyll within sight of the Alps. Craft quality is a tradition here. The Freundl Bakery has been using the best ingredients from local suppliers for 60 years to bake high-quality products according to traditional family recipes. The bakery also recognises the importance of the latest refrigerating technology. Company owner Martin Freundl made an investment for the future two years ago and installed an integral refrigerating concept from Wachtel-Stamm to replace the old refrigerating plant which had been used in production for almost 20 years. This sophisticated system made it possible to increase the refrigerating area substantially without taking up any more space. High-performance evaporators from GEA Küba were used.

The long-serving old technology no longer satisfied today‘s energy demands and had also reached the limit of its capacity. The area available for refrigeration was simply no longer large enough to be able to ensure the bakery‘s own requirements for quality and freshness in the long term while simultaneously satisfying the
growing demand. “Something had to be done. It quickly became apparent that investing in a new system made more sense economically than the “upgrading of the old”, Freundl said.

Controlled cooling without shrinkage

The Cool Rising technology from Wachtel Stamm offered the most convincing system. The integrated computer-aided system controls the cooling and fermenting of the dough pieces with minimal temperature difference at the coldest point in the system: the evaporator. The controlled cooling makes it possible to maintain the required humidity and results in the desired fermentation process – without any shrinkage. The flavour-forming enzymes continue to work in a rapid yet controlled manner. Dough pieces can thereby be stored for up to 48 hours and are ready for baking without any further final fermentation. This creates the greatest possible reliability in the ongoing production as well as maximum capacity reserves.
The system represents a technical innovation and also sets standards spatially: a 2.30 m wide bakery area in front of the three individual cold rooms were integrated into the refrigeration concept as a multi-functional space, and serve as additional cooling areas as well as a connection passage for the rooms. When the freezer rooms were opened, the cold air previously flowed into the warm bakery area; now this air is used to cool the space in front of the rooms down to +8°C. Freundl has thus gained considerably more cooling area with high energy efficiency which minimises costs. Now the product has a continuous path from start
to finish.
The greater part of all the dough pieces move directly into the different rooms through the lock tunnel of the Flash 300 blast freezer, composed of two standing evaporators from Küba positioned next to one another and which were made especially for Wachtel Stamm. The situation is different, for example, with pretzels which are pushed into the multi-functional area for stiffening. A total of 20 tray racks can easily be positioned here without blocking any transport routes. Pretzel production has thus become a lot easier.
Employees also use the multi-purpose room for the packaging and arranging of dough pieces.
The installed Flash 300 freezer is made from 1.4103 grade V2A; its base surface of 248 x 66 cm can accept up to 4 tray racks at once and guarantees a refrigerating capacity of 40 KW at to –35°C/ tc +45°C (R404). The high-performance Küba standing evaporators manufactured especially for Wachtel Stamm cool small pastry pieces to the desired core temperature in just 10 to 12 minutes; pre-baked dough pieces take a maximum of 20 minutes. The blast freezer is electrically defrosted daily at 9.00 p.m. An high reputable SPS control which was developed by Wachtel Stamm controls and monitors all individually set parameters.

Standing evaporators manufactured especially for Wachtel Stamm

After the blast freezing, the dough pieces are transferred on the tray racks into the -18°C cold bakery store or pastry/confectionery store depending on the type and use of the dough or pastry. Dough pieces which are only intended for processing the next day can also be temporarily stored in the cool rising room. All
three cold rooms are equipped with Wachtel Stamm‘s own “DE System”, which provides optimised air management. In this system, the open dough pieces do not immediately come into contact with the air flow during the storage phase. Skin formation on the chilled good is thereby prevented and the product quality
is sustainably increased. Wachtel Stamm first introduced the DE System 25 years ago. Although many have tried to imitate Wachtel Stamm’s state of the art system, the original forever remains the superior method of storing dough pieces. The bakery freezer store has a capacity of at least 72 tray racks. The main transport routes remain free at this capacity. “We even have a small buffer at peak times”. Four Küba DEBE evaporators operated in two separate chilling circuits provide a dependable cold temperature. Freundl deliberately chose the dual-circuit refrigerating system to be on the safe side. Even if a cooling circuit fails or if a summer heat wave drives up temperatures, a combination of Küba evaporators is enough to keep the deep freeze temperature constant.
The confectionary store can accept a maximum of 24 tray racks. Two Küba evaporators are installed as ceiling systems here and provide the required refrigeration capacity with a rating of 11.5 KW.

Automatic steaming prevents skin formation

The cool rising room has space for a maximum of 36 tray racks. The power rating data of the refrigeration are comparable with those of the confectionery store. In addition, the room is equipped with two additional steaming units. They ensure optimal temperature and humidification curves. The control system reacts to marginal fluctuations and intervenes automatically to make corrections. If the flour absorbs too little water, the steaming units replenish the dough surface with moisture. Skin formation is thereby avoided. The system then cools the core of the fermented dough pieces in a controlled process down to -7°C within 20 minutes. By waiving the blast freezing process, the alternative preservation method, the dough pieces are prevented from shrinking. A further advantage is that both the fermenting and cooling take place in one room during cool rising.
Defrosting takes place up to twice a day in the store rooms, as required. The defrosting process is controlled via a timer function and is directly limited by the evaporation sensors in the room. The process is initiated by the Wachtel Stamm OCTOPUS computer. This guarantees the ideal cooling climate. If the maximum defrosting
time exceeds the preprogrammed time of 50 minutes for the defrost of the evaporators, the sensor transmits an alarm through the modem to the Wachtel Stamm service centre in Hilden, Germany. Depending on the situation, either Freundl is contacted by phone or a local engineer is sent directly to the customer. The defrosting times and all the temperatures can be changed and monitored online at all times.
A drip down time of max. 5 minutes is observed after each defrosting process. The compressor only starts to run again after this time. As soon as the evaporation temperature has reached –5°C, the fans are switched back on. This prevents warm air from being blown into the room.

Modular room cooling system leaves space for expansion

The total cooling system is made up of modular rooms. However, one central condenser is sufficient for all three rooms with the multi-functional space in front of them. This is in the external area. “It was important for me that the rooms were no longer interconnected. This also gives me the opportunity to replace or expand
individual rooms”, Martin Freundl says.
The four-month construction time – with ongoing production – was a logistical balancing act. The existing cooling systems had to be completely removed before the building could be converted under the  requirements of the new system. Production was transferred to mobile refrigeration containers on the bakery’s premises in the meantime.
After the gutting of the building, the floor foundations were cut up. The floor had to be lowered to allow the new blast freezers for level-access loading to be installed. “Everything was blocked. It was right in the middle of a really hot summer,” said Freundl. Since most of the products could no longer be made using refrigeration after the start of construction, the team of 100 employees had to switch to full-on production, which resulted in a lot of overtime. “Our delivery agreements were settled. A reduction of the quantities
was just as impossible as a reduction in the variety of products,” Freundl said.
The cooling concept has now been in use for almost two years. The declared goals of optimising process routines while maintaining the proven quality and freshness with increasing demand have been met – particularly due to the cool rising room which was after a few month used to produce all pastry goods. The
morning is spent putting all the dough pieces to be baked into the bakery and the actual process starts at 11.00 a.m. The phases are completed by around 0.30 a.m. Freundl has integrated an additional buffer period which allows the fermenting time and in turn the maturity level of the products to be adjusted in the fermenting room. The pastries ar then ready for baking.