Science Questions

How much wheat to make a loaf of bread?

Mon, 20th Jul 2015

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Jerry asked:

I make my own bread using a breadmaker. I am also a keen countryside walker. When I see a wheat field I often wonder what area of a field does it take to make enough flour for a large wholemeal loaf?


Amy Goodfellow put Jerry's question to Andrew Whitley, co-founder of the Real Bread campaign...

Amy - Letís say I'm on a beautiful country farm with Andrew Whitley, co-founder of the UKís Real Bread campaign. The sun is shining, not a cloud in sight and there is wheat as far as the eye can see. Andrew, where do we even begin with this question?

Andrew - A large wholemeal loaf, baked in a tin weighs 800 grams. It takes about 550 grams of flour plus water, salt and yeast to make the dough for a loaf like this. Letís assume, itís real bread without any additives to puff it up or pad it out.

Amy - Yummy! But what's the difference between white and wholemeal flour? Does this affect the amount of wheat we need?

Andrew - Whol meal flour is what you get when you grind up whole grains of wheat and take nothing out. To make white flour, you lose about 25 per cent of the original grain, mostly the nutrient-rich brown layer and the vital wheat germ. So, we need about 550 grams of wheat for our loaf. How much land it takes to grow this depends on the farmerís production method.

Amy - I suppose production methods broadly boil down to organic and non-organic farming. I've heard it takes 8 tons of natural gas to make just one ton of fertiliser, but would that decrease the amount of land we would need to make a certain amount of wheat?

Andrew - With heavy applications of artificial nitrogen, plus spraying with fungicides and pesticides, yields of 10 tons of wheat per hectare are common. So basically, a square meter could produce 1 kilo of wheat. But if you donít want residues of toxic chemicals in your bread, you may prefer to rely on a careful farmer and a fertile soil. In which case, a yield of 5 to 6 tons of clean and nutritious wheat per hectare is possible or about 550 grams per square meter.

Amy - The non-organic stuff has a pretty high production margin then. It takes somewhere between a third and a half more field to make organic bread. How much land would I need to make one sumptuous wholemeal loaf then, Andrew?

Andrew - An area of about 1/2 to 1 meter squared is what it takes to grow a wholemeal loaf.

Amy - To me, that seems like quite a lot for just one loaf. There you go Jerry. I hope that answers your question. Next time, weíll be climbing aboard the Star Ship Enterprise to boldly go where no one has gone before to answer Patrickís questionÖ

Patrick - What are worm holes and how were they created in the universe?


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"And what are we to eat oursells then, father," asked Jenny, "when we hae sent awa the haill meal in the ark and the girnel?"
"We maun gar wheat-flour serve us for a blink," said Niel, in a tone of resignation; "it's no that ill food, though far frae being sae hearty or kindly to a Scotchman's stamach as the curney aitmeal is; the Englishers live amaist upon't; but, to be sure, the pock-puddings ken nae better."

Old Mortality, Chapter XX Pecos_Bill, Mon, 3rd Aug 2015

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