The kitchen is a great place for scientific experiments. No need for fancy chemistry kits or glass beakers, you already have everything you need in your cupboards! Here are three experiments exploring the properties of liquids with some fun and delicious results!
Osmosis Pickles (Prep time: 15 minutes)
Osmosis is the movement of water across a membrane. At first, water moves out of the vegetables into the brine because the salt and sugar in the brine make it more concentrated solution. This causes the vegetables to soften. However, over time the water differential within the vegetables and the brine equalizes and the vegetables will start to absorb the flavours of the brine.
Ingredients
1⁄2 cup of apple cider vinegar
1⁄2 cup water
2 Tbsp of sugar
1 tsp salt
1 small Persian cucumber
1 beet
1 carrot
5 radishes
1 clove of garlic
Mix the salt, sugar, water and cider vinegar in a large jar. Stir to dissolve the salt and sugar. This is the concentrated solution.
Slice the cucumber into circles. Chop the beets and carrots into snacking sticks. The radishes can be left whole or sliced in half.
Peel the garlic but leave it whole. Place it in the bottom of the jar, then fill the rest of the jar with the vegetables. There should be enough brine to completely cover them.
Place the jar into the fridge for at least 24 hours. Finish the pickles within three weeks, but feel free to reuse the brine for more pickles.
I recommend checking on the vegetables every few days to see what happened. After one day the carrots will have softened and the brine will be coloured by the beet. This is the water leaving the vegetables. After three days, the jar will have achieved an equilibrium, and the brine will have flavoured the vegetables. The longer they marinate, the more flavour will enter the cells of the vegetables. You’ll be able to see this by looking at how the cucumber and radishes turned slightly pink from the beet.
Emulsified Aioli Dip (Prep Time: 15 minutes)
Emulsification involves combining two liquids that don’t normally mix. In the kitchen, these liquids are usually oil and vinegar, or oil and water. To get oil to mix with vinegar, it needs to be whisked. This causes the fat molecules to break up enough to mix with the vinegar. Emulsifying agents help with mixing the oil and vinegar. Common emulsifying agents are mustard, egg yolk and honey. This recipe uses garlic for emulsification. Many sauces and salad dressings, including mayonnaise, start with emulsification.
Ingredients
6 cloves of garlic
1⁄2 tsp salt
1 tsp lemon juice
1⁄2 cup extra-virgin olive oil
Preheat the oven to 350°F. Trim the top off a garlic bulb and place the garlic cut-side up on a piece of foil. Wrap the garlic in foil and roast for 40 minutes, until the cloves are golden brown and tender.
Place 6 medium-sized cloves of roasted garlic in a mortar. The cloves should pop right out of their skins. Mash with the salt until they become a smooth paste. Stir in the lemon juice.
It’s time to start emulsifying! Add the oil 1 tablespoon at a time. Fully stir the oil into the garlic before adding the next tablespoon. The goal is to have all the oil mixed in for a nice thick sauce.
Non-Newtonian Oobleck (Prep Time: 2 minutes)
Growing up, my mother called this mixture guck. It was her go-to rainy day activity and had little to do with science and a whole lot to do with keeping us entertained. When my kids were little, I would make up a batch and pour it onto their highchair tray and give them some spoons and measuring cups so they could keep me company while I cooked dinner.
Non-Newtonian fluids are liquids that become more or less liquid based on force. For example, ketchup and custard become more liquid when shaken or stirred. Oobleck has the opposite effect of becoming more solid when under pressure. It’s because cornstarch has long chains of starch that flow smoothly past each other when mixed with water but as soon as you put pressure on them, they get tangled up and become solid.
Ingredients
1 cup cornstarch
1⁄2 cup water
1⁄4 tsp food colouring
Mix the cornstarch, water and food colouring in a bowl. Play with it a bit. If it seems too solid, add a few more tablespoons of water. The goal is to create an oobleck that is solid when you push on it, but liquid when you leave it alone.
No need for fancy equipment or a laboratory, just pick your favourite recipe or try out all three. Happy experimenting!
