A knife bolster is a thick junction between the handle and the knife blade which provides a smooth transition from the blade to the handle. A bolster strengthens the knife, adds durability, and provides a counter-balance. Since the handle is lighter than the blade, the bolster contributes to better balance and improves control.
Full tang, professional quality culinary knives will often have a bolster. Bolsters are typically found on forged knives, with the thickness of the bolster showing the thickness of the original piece of steel.
A bolster can also be added to knives that have been laser cut or stamped out of a roll of sheet metal. Japanese styles, such as the shun knife with a wa handle, lack a bolster entirely.
Types of Culinary Knife Bolsters
In knives with a full bolster, it can extend all the way to the bottom of the blade. A larger full bolster may have a protective shield function to prevent contact with the knife blade while using it.
Some knives have a semi-bolster, which is ground to enable full use of the knife edge when chopping. A semi-bolster also makes it easier to sharpen the blade, as compared to sharpening a full bolster.
Advantages and Disadvantages of a Full Bolster Knife
If you use a knife for going point-first into an ingredient or sawing, such as through a winter squash or when breaking down meat, a bolster may provide some finger protection. Some chefs prefer a knife with a bolster when fileting or boning fish, as their hands will get slimy and slippery.
Other cooks have simply gotten used to the bolster on a favorite knife and like the shape and handling of the knife. If you compare two different German knives from the same manufacturer, you will see there is a blade shape difference between the full bolster and the semi-bolster models, resulting in a different angle for cutting.
For chopping and most common kitchen tasks, a semi-bolster or a knife without a bolster will perform well. You will be able to use the full length of the blade for these tasks. As well, if you sharpen your knife often (such as daily if it gets heavy use in a restaurant or commercial kitchen), it will be much easier to sharpen a knife without a bolster. You will have to be a little more careful with your fingers and towels when cleaning with the sharp end near the tang.
Whether you choose a knife with a bolster or not will depend on how it feels and what you are used to using. Some cooks prefer one over the other, while some cooks use different styles for different tasks. When buying a knife, consider all of the elements of the knife, including the quality, length, shape, and thickness of the blade, and the shape, design, and material of the handle. As well, consider how you are going to sharpen the knife and be sure you have the tools to do so.