Why Do Coffee Shops Use So Much Ice? What's Special About Handmade Ice Cubes in Coffee Shops?

Why Coffee Shop Ice Melts So Slowly

Many customers have wondered why ice cubes made at home don't achieve good cooling effects, melting completely in water shortly after being added, while ice provided by coffee shops melts very slowly. Even after finishing an entire iced Americano, the ice cubes seem virtually "unharmed." Why is this? What kind of "special ice" do coffee shops use?

The Role of Ice Cubes

FrontStreet Coffee mentioned in their article "What Are the Considerations When Adding Ice to Coffee?" that as an indispensable auxiliary element in cold beverages, ice cubes not only serve the recognized function of cooling but also help us achieve several objectives simultaneously: locking in coffee aroma, adjusting concentration, and maintaining low temperature, thereby enhancing the taste of iced coffee.

Additionally, different production processes, shapes, and volumes of ice cubes all affect the taste experience of cold coffee from preparation to the first sip and until the last drop.

What Kind of Ice Do Coffee Shops Typically Use? Why Doesn't It Melt Easily?

Based on various factors, when selecting ice solutions, café owners prioritize production efficiency first, therefore considering the use of ice machines. Secondly, they want to achieve ideal taste in their iced coffee, so they need ice that "cools quickly and melts slowly," while developing corresponding "ice strategies" for different beverages based on actual conditions.

Freezing and ice melting are actually heat conduction processes, and many factors affect the rate of heat transfer, such as ambient temperature, the temperature of the liquid and ice cubes themselves, and the contact area between ice and liquid. Regarding the phenomenon of "coffee shop ice melting slowly," FrontStreet Coffee believes that differences in equipment and varying amounts of ice used are the main causes.

Compared to the refrigerators we commonly have at home, commercial ice machines designed specifically for business operations have only one function: "making ice." Their core lies in high efficiency and continuous, stable output of ice cubes. The ice they produce surpasses home-made ice in terms of purity, hardness, and core temperature. Moreover, to achieve multiple uses, ice produced by such equipment is typically regular square or crescent-shaped, relatively small in volume, and structurally more conducive to stacking;

Whereas ice cubes we make at home are mostly small spherical or irregular squares, which not only have low stacking density in cups but also occupy a larger volume at the same weight. Therefore, the reason why coffee shop ice melts "slower" than ice from home refrigerators stems not only from differences in production methods but also from the fact that different ice shapes result in a higher actual ice proportion in coffee shop preparations.

Can Refrigerators Make "Special Ice"?

If considering all the above factors, using ice machines would obviously be the optimal choice for business operations. So why does FrontStreet Coffee still insist on using refrigerators to freeze ice cubes?

Although commercial ice machines can indeed solve many of our preparation challenges to some extent, because the ice cubes they produce are generally too small and often hollow, when placed in hotter coffee, they can easily melt too quickly, leading to the coffee temperature not dropping sufficiently while being over-diluted prematurely. In high-temperature climates of 40°C, iced coffee cannot maintain its quality for very long.

After comprehensive consideration, to ensure that all iced coffees on the menu can achieve relatively good cooling and dilution effects, and to solve the problem of coffee quickly warming up and changing flavor after cooling, FrontStreet Coffee decided to adopt a static freezing method—using larger-sized molds directly in refrigerators to make ice. This approach has both advantages and disadvantages. The benefit is obtaining solid ice cubes large enough to adapt to various coffees, making them universally appealing; the drawback is obvious: low efficiency, requiring manual water filling each time, with it taking at least 40 hours to successfully freeze a batch of ice cubes.

Additionally, to explore whether the freezing time of ice cubes affects their melting speed, FrontStreet Coffee conducted a small experiment, using freshly removed ice cubes from freezing molds and "old ice cubes" removed two days prior to brew the same coffee beans using identical parameters to see if there were differences. The specific parameters were as follows:

Coffee beans: FrontStreet Coffee's Guji Grade 1 coffee beans
Dose: 15g
Ratio: 1:10
Ice: 80g (4 cubes)
Water temperature: 92-93°C
Grind size: EK43s-9 setting / C40-22 setting
Three-stage pour: 30g+60g+60g

(Left: Refrozen ice cubes, Right: Freshly removed ice cubes from mold)

Although both batches of Guji Grade 1 iced pour-over exhibited gentle tropical fruit, orange, cream, and black tea notes, there were differences in mouthfeel and concentration. Compared to coffee made with "fresh ice" just removed from the mold, the Guji brewed with refrozen ice not only had fuller citrus acidity and black tea sensation but also maintained low temperature longer in the cup. After completely returning to room temperature, one could still taste a hint of honey-like sweet aftertaste.

This is because, at the same volume, refrozen ice cubes that have been in a cold environment for extended periods are much denser than freshly removed ice cubes. Therefore, even in hot coffee, their melting speed is slower, allowing the coffee liquid to be diluted and cooled in a short time, resulting in correspondingly better flavor and concentration.

If you also want to make your ice cubes denser and more useful, you might want to follow FrontStreet Coffee's approach: choose slightly larger-sized molds for manual ice making, remove the ice only after water has completely frozen into solid form, then store it in a clean container for use as needed.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473