Rare, Medium or Well done? The science of a perfect steak

Vegetarians, look away now. Today’s post is distinctly carnivorous. Read on, you red meat eaters, as we are discussing an issue of upmost culinary importance…

You can’t beat a good steak, I say. Quality medium-rare beef fillet; served with fries and salad is true feel-good food. I know I’m not the only one: it is one of the most popular last meals for death row inmates (after deep fried chicken). Not that that should necessarily be a measure of good taste.

Personal preferences aside (an overcooked sirloin is a travesty), is there a secret to grilling the tastiest, most nutritious steak? Whether or not you like yours with mustard, here’s some science to guide you in the kitchen…

How long should you cook your steak?

Recent years has seen the emergence of a popular ‘raw food’ movement. Dehydrating food to make it palatable, raw-foodies argue that cooking food destroys valuable vitamins and enzymes, rendering it nutritionally impoverished. It sounds logical, but – especially with vegetables – is often false. Many vegetables actually gain nutritional value after careful cooking or steaming. Furthermore, a strict vegan raw food diet is not good for long term health (references below).

Meat isn’t the sort of thing you tend to eat raw (uncooked pork and shellfish are particularly best avoided). Red meat is notable in that it contains a good source of B-vitamins that are essential for healthy muscles, skin and nerves. It also contains iron and other important minerals. Like most things however, steak should be in moderation as a high intake is associated with colon cancer and other health nasties.

So what happens to the good nutritional qualities of steak after a close encounter with a hot plate?

Swiss researchers Gerber, Scheeder and Wenk (great name) have largely resolved this rare vs. well-done health debate. Cooking 200g samples of a variety of meats, they measured the change in vitamin and mineral content in each. After cooking, all meats produced similar findings, but we’ll focus on the beef:

• The longer steak is cooked, the fewer vitamins it contains
• Cooking meat in water reduces its vitamin content further (the vitamins leech out into the water)
• The levels of iron and zinc increase with cooking
• Fat levels drop with cooking

The last point is well worth remembering if you are on a diet, or care about your arteries.

Cook steak from frozen or fresh?

I’m a purist, and wouldn’t dream of cooking beef from frozen. I’m also a pragmatist, and high street butchers can be difficult to come by. It’s a particular issue for restaurants and food outlets who need to buy and store meat in bulk. Researchers from Kansas State University (a city famous for the steak house featured in Top Gun) investigated the problem. They methodically weighed and sliced Top Sirloin and Loin cut (to 2.54cm thickness with a band saw, no less), cooked, then tasted them from either frozen or thawed state.

Six ‘trained panellists’ ate and rated the meat according to tenderness, juiciness, flavour and toughness. The shear force of each steak was also measured in a machine (crudely, a measure of how squidgy it is). All the results tabulated and statistically analysed. A lot of work, but all in a good cause…

Their findings, based on a medium-well done steaks (internal meat temperature 70°C) were that:

• Steaks cooked from frozen taste just as good
• Frozen steak looks significantly darker after cooking
• A frozen steak shrinks considerably more than a thawed one (losing 30% in bulk and 20% in size)
• Frozen steaks taste tougher – although incidentally they record the same on the ‘squidgy’ factor (Shear Force) readings.

So, if taste and time are your priority, there’s no harm in cooking a steak from frozen, it just tastes a bit tougher.

To conclude, if you want vitamins: go rare. If you want iron: go well done. Want tender meat? Don’t freeze it. On a diet? Cook it to smithereens. And if you want a long life, eat fish.

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Thanks for reading – feel free to leave comments below…

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REFERENCES:

Koebnick, C., Strassner, C., Hoffmann, I., & Leitzmann, C. (1999). Consequences of a Long-Term Raw Food Diet on Body Weight and Menstruation: Results of a Questionnaire Survey Annals of Nutrition and Metabolism, 43 (2), 69-79 DOI: 10.1159/000012770

Faller, A., & Fialho, E. (2009). The antioxidant capacity and polyphenol content of organic and conventional retail vegetables after domestic cooking Food Research International, 42 (1), 210-215 DOI: 10.1016/j.foodres.2008.10.009

Gerber N, Scheeder MR, & Wenk C (2009). The influence of cooking and fat trimming on the actual nutrient intake from meat. Meat science, 81 (1), 148-54 PMID: 22063975

Obuz E, & Dikeman ME (2003). Effects of cooking beef muscles from frozen or thawed states on cooking traits and palatability. Meat science, 65 (3), 993-7 PMID: 22063680