Breville Barista Touch Espresso machine: Should a novice use the dual-wall or the single-wall filter basket?

Let's not play games. I find it counter-intuitive but the dual-wall filter basket is the basket beginners should use. I expect to see holes, lots of holes, in the bottom of a filter basket. It just seems reasonable.

 

The dual-wall filter basket, with only one, small exit hole in the bottom, looks strange. What advantage could there possibly be? Answer: the one hole raises the extraction pressure. Think of it as placing a thumb over the end of a hose. And why is this good?

 

The high pressure created by forcing the espresso through one, final, small hole smooths over flavour imperfections while producing a thick and stable crema. Critics see this as a cheat: ample crema created without perfect extraction.

 

Puck channelling happens less frequently when a dual-wall filter basket is used. Grind size, dose weight and tamping consistency all have less influence on the resulting brew.

 

On the other hand, the single-walled filter basket, with rows and rows of small perforations in the stainless steel bottom, depends on proper grind size, dose weight and consistent tamping to control extraction pressure. Controlling the variables calls for more skill on the part of the barista.

 

I have heard dual-walled filter baskets called "training wheels" for budding baristas. Uneven tamping, incorrect grind size or dose weight errors still result in a  consistently acceptable espresso with no fuss, no muss. Note the word acceptable. Sadly, the dual-walled filter basket also mutes the unique flavour notes found in different coffee beans. But, not to worry, most novice espresso makers do not notice. Acceptable is acceptable.