“Fat is flavour”– this adage is not always true (e.g. soy sauce), but in the case of burgers, it is irrefutable. A juicy, beefy tasting burger is partially to do with the inherent moisture and flavour of the muscle fibres, but what really causes chicken to taste like chicken, pork to taste like pork, and beef to taste like beef is mostly to do with lipids, aka fatty tissue (Harold McGee). Think about the flavour of chicken skin (more than 40% fat) vs skinless breast (just over 1% fat). We’re after a reasonable amount of fat inherent to the cut we choose, and keeping it nicely nestled in a loose (but not too loose!) patty.
That said, you can have too much of a good thing – at higher ratios of fat (closer to 30%), we find the structure of the patty suffers (too many recesses where the fat has melted, with a resulting crumbly configuration), in addition to a ‘greasiness’ that begins to take hold. On the other hand, at lower percentages of fat, ‘healthy burgers’ (or badly formed burgers, which we’ll address in the coming weeks, where a good ratio to start with renders poorly during cooking, with most of it seeping out on the grill), the only way to produce a burger that isn’t dry is to load sauce on. We see this time and time again: a poorly constructed, bland patty, brought back from the brim of desiccated banality by mayonnaise, ketchup and mustard (often the only contributors to the juiciness and flavour of a subpar burger). (Sidenote/newsflash: mayonnaise isn’t really all that healthy). Light pressure on a burger patty should reveal an even distribution of juiciness inherent to the beef on its own. A patty and bun alone should be juicy and flavourful. We don’t hide behind sauce and cheese (but we do like them, as long as they don’t distract from the beef itself).