Can you substitute bacon for guanciale?

You can, and it'll still taste good, but the smoke changes the dish. Unsmoked pancetta is the closer swap.

Is guanciale fattier than bacon?

Yes, much. It's mostly fat with thin streaks of meat, which is why it melts into a sauce instead of staying chewy.

Guanciale vs bacon: what's the difference?

Guanciale is Italian cured pork cheek, unsmoked and very fatty, while American bacon is smoked pork belly; guanciale tastes porkier and funkier, bacon smoky and sweet.

Guanciale

Very light

Indulgent

Subtle

Big punch

Mellow

Zingy

Pure pork richness, peppery and a bit funky, no smoke.

What does Guanciale taste like?

Bacon

Very light

Indulgent

Subtle

Big punch

Mellow

Zingy

Smoky, salty-sweet and crisp, the loudest thing on the plate.

The real difference

Bacon is pork belly cured, often with sugar, then smoked and sliced. Guanciale is jowl cured with salt and pepper and hung to dry, never smoked. Guanciale has more fat and melts into pasta sauces, while bacon brings smoke and sweetness that can take over a dish.

Side by side

GuancialeBacon

CutPork cheek and jowlPork belly

CuredSalt and pepper, air-driedSalt and often sugar, then smoked

TastesPorky, peppery, funkySmoky, sweet, salty

On a menuRoman pastasBreakfast, burgers, BLTs, everything

Which to order

Order guanciale if you want carbonara the way Rome makes it.
Order bacon if you want smoke and crunch front and center.

Quick questions

Can you substitute bacon for guanciale?: You can, and it'll still taste good, but the smoke changes the dish. Unsmoked pancetta is the closer swap.
Is guanciale fattier than bacon?: Yes, much. It's mostly fat with thin streaks of meat, which is why it melts into a sauce instead of staying chewy.