Now, I must confess I didn’t eat porridge as a child and I only eat it occasionally now, but I have many memories of the oats-based dish. David drew a circle, a cross section through the spurtle, and an elongated ellipse, a cross section through a spoon, and flow lines as they moved through the porridge. For any given speed of movement, the energy needed to move the spurtle would be lower than the energy needed to move the spoon. Likewise, for any given amount of energy, the spurtle would move faster than the spoon. Shear stress depends on speed of movement. So, with a spurtle, it takes less energy to get a certain amount of shear stress and thus a certain amount of lump-disruption. Designed in the Highlands of Scotland in the 15th century, this unique kitchen tool was originally used to stir oatmeal, soup, stew, and broth. Our wood spurtle is useful for even more applications including stirring, mixing, whisking, and icing. Can I put my spurtle in the dishwasher? Serve with chopped or sliced banana and a sprinkling of chia seeds or top with other fresh fruits of your choice.

I also like to add a splash of vanilla extract to my porridge, it gives a hint of sweetness without adding sugar. I usually top my porridge with chopped banana and chia seeds, but you can use any fruits, nuts or seeds that you like. I make my porridge with unsweetened almond milk. It's dairy free, sugar free, low in calories and works perfectly in porridge. You can substitute the almond milk for cows milk if you prefer though, they both work equally well. There are two materials to choose from. Silicone: These are dishwasher-safe, and heat-safe up to 400°F. And there are loads of colors to choose from. Wooden: These are just so pretty, you wouldn’t be at all sorry to have them at the table as serving pieces. Can spurtle go in dishwasher? Carrbridge is a fairly small place but we have people coming in first thing in the morning at 10am and they stay there until 6pm until it is all over. Since taking up the Sugar Free February challenge, cereal and toast have been out of bounds for me, so my breakfast habits have had to change, fast!The graph appeared and I confess it was really exciting to watch the points appear. A straight line down from top left to bottom right over a huge range of stirring speeds. As David had suspected, the viscosity declines linearly with the speed of rotation.

You can think of shear stress as being a difference in the speed of flow of the liquid across a small distance, multiplied by its resistance to flow. That resistance to flow is what we think of as viscosity. In a viscous liquid, like honey, the stirrer produces a lot more shear stress than it would moving through water at the same speed. But there’s a crucial difference between honey and water. Oats contain a type of soluble fibre called beta-glucan, which studies have shown can help to lower your cholesterol. They also contain iron, zinc, magnesium and B vitamins. If you are making this porridge with milk like we have, then the vitamin and mineral content increases, as does the calcium content. I should explain that Dr David A. Gagnon, the physicist in question, is the son-in-law of one of my dearest friends, who happened to be visiting when I was editing the episode. That was how David came to know of my puzzlement – and he has access to wonderful machines that can make very accurate rheological measurements. Rheology is the study of flow, and David’s idea was that the faster the stirrer moved through the porridge, the lower the viscosity of the porridge would be. Shear stress in a material like porridge would be greater at higher flow speeds, and it is the shear stress that gets rid of lumps.

With porridge still a regular at breakfast tables across the land, Brian Stormont looks at the history of a true Scottish classic. You put that down in front of anybody and they can do what they like with it – they can add sugar, they can honey, they can add molasses, but the making of the dish is porridge, salt and water – nothing more.” In an age of too many kitchen appliances with too few uses, it’s liberating to see a simple tool that can do a host of things. But according to Harry Clarke of Kitchen Carvers, another spurtle manufacturer, there's one thing you shouldn't do with the spurtle. The argument for using salt is that it is a test of Scottishness and it is only the Sassenachs who would put sugar on their porridge! World Porridge Championships

Less healthy (but totally yummy!) toppings include a sprinkle of sugar, drizzle of maple syrup, honey or golden syrup, small handful of chocolate chips or a dollop of Nutella or jam. However, the tool he called a spurtle looked more like a wooden spoon with the contour of a spatula. Thanks to the flat surface area, Kerr used it for more than just cooking porridge, like stirring melted marshmallows for Rice Krispies treats. What do you call a porridge stirrer?

Organiser Charlie Miller said: “We have done an online contest where we have invited people from all over the world to submit videos of three-to-five-minute duration of them making a speciality porridge dish. Heating up food, for example over a hotplate, does not happen evenly. Heat is transferred from the stove to the pot or pan and from there to the food that is being heated up. The lower thermal conductivity of the contents of a cooking vessel – compared to the stove or pot – means that the contents near the bottom heat up much faster than everything above it. In honour of last week’s 29th annual Golden Spurtle championship, I refer you to two previous epsiodes. She added: “Oats are the flower of our Scottish soil and through that magic cauldron the porridge pot Scottish oatmeal has been transmuted through the centuries into Scottish brains and brawn.” Salt or sugar? But what does the organiser of the World Porridge Championships believe should go into a bowl of oaty goodness?