The multi-boiler technology is based on coffee groups and a steam boiler that work completely independently. Each group and boiler have their own autonomous heating system, safety device and precise electronic temperature control.This system is much more evolved than the conventional system of a single boiler or the dual boiler machines.
The heart of the machine.
Manufactured in 100% AISI 316 stainless steel. Welded with plasma, both inside and out, to avoid any cracks that might cause corrosion.
The design and material of the coffee groups provide:
Our saturated coffee groups are exceptional.
The heaviest on the market.
The 6 kg of thermal mass in very thick AISI 316 stainless steel, along with its large water storage capacity (1.3 litres) offers outstanding thermal stability.
The groups are welded directly to the boiler, which is also in stainless steel, with no additional material being added during the welding process. Designed to last ‘forever’ and offer maximum thermal stability on a continuous basis.
Engineering of the coffee group
The coffee group was meticulously designed, studied and tested over a period of several months. The goal was to produce a highly reliable and thermally stable group. The main objective is to achieve the maximum thermal stability within the group whether on standby or fully operational. We have achieved constant recirculation, which means that the system does not undergo any variations during the extraction process.
The preheated water that enters the group (70-80ºC) does not enter directly. It first passes through a tube in the boiler, avoiding any thermal shock and quickly adapting to the temperature of the boiler.
Manufactured in 100% AISI 316 stainless steel.
Plasma-welded both inside and out.
Extremely sturdy: Boiler thickness: 2.5 mm / Lid thickness: 10 mm
Large capacity: 8/12 litres
Weight: 9 kg
Every Big Dream has a boiler dedicated exclusively to producing steam; its large capacity produces a dry steam that facilitates the preparation of cappuccinos, lattes and macchiatos with exceptional power.
In addition, with more than 9 kg of thermal mass in very thick AISI 316 stainless steel it provides exceptional thermal stability. This means that the steam pressure is kept constant and it uses less energy while at the same time maximising steam production.
Lime scale hardly ever adheres to stainless steel. This makes cleaning much simpler and means repairs are a thing of the past.
Our boilers (coffee and steam) include a thermal sleeve which reduces the machine’s consumption by up to 35%.
Stainless steel, meanwhile, is a very bad heat conductor and thus an extremely bad dissipater. Therefore, it is a material that requires less power to maintain thermal stability. This characteristic of stainless steel results in improved energy efficiency. By maintaining the optimum operating temperature, the machine requires less electrical power.
As well as using this material, our engineering department also introduced additional measures to achieve energy savings of 40% compared to a traditional machine made from copper and brass.
Triple Temperature Control
(PID) (Proportional Integral Derivative)
Easy and optimal temperature regulation lets you select the appropriate extraction process for each coffee, producing excellent results.
Our system offers a precision of 0.2ºC which considerably reduces any heat fluctuations within the coffee group.
The barista simply has to select the desired temperature and Big Dream will do the rest.
To do so, Big Dream has triple temperature control:
1. Dynamic pre-heating/temperature control of the water entering the coffee group through the mixer valve. The water that supplies the coffee group will enter pre-heated to the required temperature.
2. Control of the temperature of each coffee group (PID).
Each group is completely independent and easy to control by the general or individual display (precision of 0.1ºC).
The temperature of each group is controlled by an NTC sensor. The high-speed heat sensor replaces the traditional mechanical thermostat. These high-precision sensors are immersed in the water of each distribution group. The sensors activate the element by means of a static relay (solid state relay). They improve thermal stability, eliminate mechanical failure, and significantly reduce heat fluctuations in each coffee group.
3.Control of the steam boiler/water temperature (PID)
The main objective of the pre-infusion is to fully and evenly moisten the coffee tablet before the extraction phase, improving its flavour. The aim is to produce a cup of coffee with more nuances, flavours and aromas, and to adapt the coffee machine to the numerous different sources and types of coffee roast.
In machines with very precise temperature control you need a good pre-infusion system that lets you extract the full gamut of complexities from the coffee. Better control of the pre-infusion phase gives you better control of the distribution process.
There are two pre-infusion options:
Classic and Soft
This lets you achieve double ‘flavour profiling’. Completely programmable in each group and each dose selection independently and easily by using the display. This is always done electronically and is perfectly controlled to ensure the barista’s operation is always the same for consistent espresso quality.
The idea is not just to moisten the puck. Soft pre-infusion makes the pre-infusion process an integral part of the extraction.
Yet by changing the pre-infusion time, the grind point (this pre-infusion allows a finer grind), the quantity of coffee, etc., you can obtain other ‘pre-infusion profiles’.
A soft pre-infusion lets you extract new flavours and aromas from your coffee. It also lets you use finer graduations when grinding. In addition, a lower-pressure impact on the dry puck also helps to avoid channelling.
The most logical thing is to programme the soft infusion for the seconds when you see the coffee coming out of the filter holder, which will depend on the grind level, the type of coffee and the amount of coffee per puck.