Espresso guides

Short, sourced guides to the questions behind the compatibility data — what the specs mean and what actually matters when you're buying a part.

• Espresso portafilter sizes explained — What size your machine is (54, 57, 58 or 52mm) and why parts don’t interchange across sizes.
• Bottomless portafilters — What a naked portafilter shows you about your extraction, and which one fits your machine.
• Single-wall vs dual-wall baskets — Non-pressurized vs pressurized — which one you want, and which baskets are which.