What is the difference between a carboy and an demijohn?

Answered by Randall Whitlock

The terms “carboy” and “demijohn” are often used interchangeably, but there is a subtle difference between the two. Generally, a carboy refers to a container with a capacity of 5 gallons, while a demijohn typically has a larger capacity of 15 gallons. However, it's important to note that these terms can vary depending on the region and context in which they are used.

In my experience as a sommelier and brewer, I have come across both carboys and demijohns during the fermentation and aging processes of various beverages. I find that the size of the vessel plays a significant role in the overall outcome of the product.

Carboys, with their smaller size, are often preferred for home and winemaking. They are relatively easier to handle, transport, and clean. Additionally, their smaller capacity allows for more precise control over the fermentation process, as it is easier to monitor and adjust variables such as temperature and oxygen exposure.

On the other hand, demijohns are typically used in larger-scale productions or for aging beverages that require a longer maturation period. The larger capacity of a demijohn allows for a greater volume of liquid to be aged, which can result in a more complex and well-rounded flavor profile. However, handling and moving demijohns can be quite challenging due to their size and weight.

Another factor to consider is the material from which these containers are made. Both carboys and demijohns can be found in various materials such as glass, plastic, or even stainless steel. Glass carboys and demijohns are often preferred for their inert nature, which means they do not impart any flavors or odors to the contents. Plastic carboys and demijohns, while more lightweight and easier to handle, may have the potential to affect the taste of the if not made from food-grade materials.

To summarize the key differences between the two:

– Capacity: Usually 5 gallons
– Preferred for: Home brewing and winemaking
– Advantages: Easier to handle, transport, and clean; allows for more precise control over fermentation

– Capacity: Usually 15 gallons
– Preferred for: Larger-scale productions or aging beverages
– Advantages: Allows for a greater volume of liquid to be aged; can result in a more complex flavor profile

While the terms “carboy” and “demijohn” are often used interchangeably, there is a difference in their typical sizes and applications. Carboys are smaller and commonly used in home brewing, while demijohns are larger and often used for larger-scale production or aging beverages. The choice between the two depends on the specific needs and goals of the brewer or winemaker.