Sainsbury's and University College London crack the perfect pancake flip

pancake flip

A flippin' end to tonnes of pancake batter wasted each year

Having sold almost 70 tonnes1 of pancake mix in the lead up to Shrove Tuesday in 2010, Sainsbury's unveils how Brits can achieve the perfect flip, with the help of University College London.

Millions of Brits will today celebrate Shrove Tuesday by wielding their frying pans in an attempt to turn out perfect pancakes - but not all ingredients will make it to the plate.  Instead, they will end up in the bin as Brits struggle to get their flippin' technique just right.  To prevent pancake panic, Sainsbury's has teamed up with the pancake boffins at UCL to reveal the perfect pancake formula.  It seems that size really does matter, as well as the heady heights we're prepared to go to!

According to University Professor of Mathematics Frank Smith, the simple mathematical formula for the perfect flip is:

L = 4×H /π- D / 2

(L = hand distance from inner edge of the pancake / H = height of flip / D = diameter of pancake)

Or a more detailed formula for the pancake connoisseur is:

[U, ω, V, L] = [(2gH)1/2, π(g/ 8H) 1/2, (g/ 32H) 1/2(8H - πD), V / ω]

(U = upward speed of centre of pancake / ω = rotation rate / V = upward speed of inner edge of pancake / g = 9.81 m/s2 (acceleration due to gravity)

Professor Smith comments: "Last year Sainsbury's sold 86% more pancake mix during the week before Pancake Day to millions of people - many of which would have struggled to perfect their pancake flip. We all know that no-one enjoys wasting ingredients but there are many factors and risks involved in producing a perfect pancake. 

"We've discovered that the wrong direction or speed, for instance, will mean that the average flipper may ruin two or even more pancakes trying to perfect their technique. By working with Sainsbury's, we aim to reduce this waste by advising Brits how to achieve the perfect flip."

Professor Smith's Methodology

Hold the frying pan horizontally with the cooked pancake in it. Estimate how high you'd like the pancake to fly, say to a height H (30cm or about one foot, as a first go). Also estimate the diameter D of your pancake, measured in the direction of the handle. D might be 10-20 cm or so.

As to where precisely to put your hand(s), work out L from the formula above and hold the handle at a distance L cm from the inner edge of the pancake. Then toss the pancake quite abruptly to a height H cm. You should now be able to carry out a 180-degrees flip.  If you want a 360-degrees flip use 2×π in the formula instead of π, and so on.  

Remember the four Cs

  1. Cook it! Use a recipe that's right for the temperature of the pan, amount of oil, the mixture whether traditional or not, and the time involved.
  2. Check it! Ensure it is not stuck to the pan and there is no free oil.
  3. Chuck it (upwards)! Practise - try a little jump first. Use two hands together - not too timidly, not too hard. Pancake weight is 100 grams (including wet ingredients); and you need on average a pancake-speed of about 2.5 m/s (just over 6 mph) to reach a height of say 30cm. You also need to produce a pancake rotation rate of about 6/s but the formula should ensure that. A smallish flip takes around ½ a second.
  4. Catch it! It comes down with approximately the same speed as at the start. Clearly we want vertical motion, in order to avoid chasing around the room.

Terms and conditions apply

  • Complications from solid mechanics and internal material reactions could be present in some instances.
  • It's good to practice by tossing up a thin book and aiming for a single 180-degrees flip.
  • Air resistance normally should be negligible.
  • How you do the toss is all-important.

Last year alone, Sainsbury's saw sales of pancake ingredients increase the week before Shrove Tuesday2, with ready-made pancake mix sales growing 86%, squeezed lemon 44% and caster sugar 12%.

Notes to editors

  • 1 Sainsbury's sold 68 tonnes of pancake mixture from 7 Feb to 20 Feb 2010.
  • 2 Percentage increase in sales from w/c 07 Feb to w/c 14 Feb 2010.
  • Shrove Tuesday is on Tuesday 8 March this year, much later than most years
  • Professor Frank T Smith - Goldsmid Professor of Applied Mathematics was also responsible for the mathematical formula for the perfect stone skim
  • Sainsbury's approach is to help and inspire customers to eat a healthy balanced diet by promoting healthy eating and active lifestyles.
  • Sainsbury's looks at ways to reduce fats, salt and additives in our products, without compromising on quality or taste. Sainsbury's is also committed to providing customers with clear and transparent labelling, to help them make informed choices about the food and drink they buy.



About the article

  • Posted on: 08 March 2011
  • Type of article: Press release