We've shown you how to make homemade versions of ketchup, mustard, mayonnaise and Sriracha. Those all taste great but there's one problem: they'll often only last a couple of weeks in your fridge. Lengthen that timeline by adding cultured whey.
Culinary weblog Eating Rules explains how you can use whey from yoghurt to expand the shelf life of your home-cooked treats. You know when you open a cup of yoghurt that has been sitting in your fridge for a while and it has a clear yellow-ish liquid on top? That's whey. Any organic non-Greek yoghurt will have all the positive bacteria you need to culture your condiments.
Line a colander with a tea towel, place that over a bowl, and pour the jar of yoghurt on the towel to sit for eight hours. The whey will strain through the towel into the bowl and the leftover yoghurt will have a consistency more like Greek yoghurt. You can store this whey in a glass jar with a towel covering for months in your fridge.
When you make a condiment, add four tablespoons of whey, mix, and place in a glass jar. Let it sit on your counter at room temperature for two to four days; this will allow time for the bacteria to do its work. When done, place the condiment back in your fridge and use as needed for up to three months. As well as enhancing the shelf life, this process adds nutritional value to your food -- the bacteria helps with digestion and increases some vitamin and enzyme levels.