The chips are hot. The burger has been grilled to perfection. Everything's been delicately salted. There's only one thing missing: ketchup. And it won't come out of the freaking bottle.

If you're a true ketchup lover, this will be a familiar situation indeed, particularly if you're the type of purist who prefers the traditional glass bottle. Luckily for us however, scientists have been working studiously to figure it out. And (finally) they've come up with a solution. According to Dr Anthony Stickland, from the University of Melbourne, you must first understand what you are dealing with. “If you tilt a bottle of water, the water flows out because it is a liquid. But tomato sauce prefers to be in the bottle because it is technically a solid, not a liquid,” With that in mind. Dr Stickland has the following tips: 1. SHAKE (WITH LID ON!) “Always start by giving the sauce a good shake,” says Dr Stickland. “You need to overcome the yield stress to mix it, so it needs a decent oomph – briefly invoke your inner paint shaker. Remember to keep the lid on, of course.” 2. TURN THE BOTTLE UPSIDE DOWN “If there’s not much left in the bottle, you may need a strong whack to dislodge tomato sauce from the bottom. Turn the bottle upside down (still with the lid on) and thrust downward at high speeds, accelerating both the ketchup and the bottle. Swiftly stopping the bottle should slump the sauce into the neck.” 3. THE TILT AND POUR “Now you’re ready to pour some sauce. There needs to be some force to overcome the yield stress, but not too much – the last thing you want is sauce running down your hand or, in the paint analogy, paint running down the walls before it dries,” says Dr Stickland. The good doctor understands that this method may not always work. This is where "some sort of encouragement, like tapping, slapping or whacking," is required. But how much whacking exactly? “You need to find the ‘sweet spot’ of force needed to move it towards your burger." says Dr Stickland. "Start by pointing the open end of the bottle toward your food at an angle of around 45 degrees with one hand around the bottle neck, and the other delivering gentle but firm taps on the bottom of the bottle. Increase the force of the taps until you balance the force applied with the mechanical strength of the sauce in order to get it to flow.” You're welcome. Heinz Tomato Ketchup Illustration Print, €18.26 from Nomeo on Etsy.