Searing meat to seal in the juices

We all know, because we have been told for so long (even by celebrity chefs and authoritative cook books), that you should begin cooking meat by searing it to seal in its juices.

This long-standing truism was most famously debunked in 1989 by Harold McGee in his remarkable book On food and cooking: The Science and Lore of the Kitchen.

This is how it affected a young cook destined to become synonymous with the modernist cooking movement, Heston Blumenthal:

“There it was, in black and white, on pages 115-16: ‘searing does not seal’, a declaration as shocking and radical in its way as Copernicus’ assertion that the earth orbits the sun, because it contradicted a belief so widely held that it was presented everywhere as fact. … [Harold McGee] encouraged me to adopt a totally different attitude towards cuisine that at its most basic boiled down to: question everything. For if the equation ‘searing = sealing’ was false, how many other basic kitchen principles were, in fact, untrue?”

McGee’s On Food and Cooking is an amazingly thorough and rigorous account of the science of food and cooking. The searing fallacy goes like this…

The ‘idea’ began in the mid 19th century when a German chemist (Justus von Liebig) published his Researches in the Chemistry of Food. In it he claimed that high heat created a crust around meat that prevented juices from escaping during roasting. The idea was embraced enthusiastically, and swiftly became kitchen lore.

It was proven to be entirely wrong soon thereafter, but the idea was so compelling that evidence for it was irrelevant. The idea turned out to be stronger than the facts.

McGee’s elegant and concise summary: “We do know for a fact that, whether done early or late, searing does not seal, but it does brown: it won’t prevent flavour from escaping, but it creates flavour via the complex browning reactions”.

The home cook can tell that searing is useless (for sealing) by:

1. Meat sizzling – this is because juices escape from the meat, hit the hot pan and turn to steam – if searing sealed, meat would not sizzle.

2. Beads of juice on the surface of the meat  – this liquid came out of the meat – if searing sealed, it would not be there.

3. Liquid and brown bits in the pan – this can only have come out of the meat – if it was sealed, the pan should be dry and clean.

4. Juices on the plate – a seared steak will still leak juices when plated – clearly it’s not sealed.

In case you might be wondering whether searing at least seals a bit; controlled studies indicate that the effect is nil.