Put the yogurt and salt in a large bowl and mix to combine. Line a colander with muslin cloth or a nut milk bag and set over a bowl. Transfer the yogurt to the cloth or bag and tie to close. You can place a heavy weight over the yogurt and allow it to drain over the colander, or, if you have the option, you can tie the bag over a sink faucet you are not using or a cabinet knob and allow gravity to speed up your work. Set aside for 24 hours. Open the bag and use a spatula to mix the strained yogurt mixture (this will bring the dryer sides into the middle and allow the moist center to drain some more) and repeat the draining process for another 24 hours. Open the cloth and mix the strained yogurt to smooth out its consistency. It should be quite dry at this point. Shape into two balls and set them on a muslin- or paper-towel-lined plate. Cover with a cheesecloth (this will prevent dust from getting in as it dries) and set in a dry, sunny place, ideally with fresh air, for 24–48 hours. If you live in a dry climate and have a sunny balcony, that is ideal; otherwise, a sunny window that you open for air periodically will do. Alternatively, place the balls on a paper-towel-lined plate and set it in the fridge, uncovered, for about 4 days. Change out the paper towels if you feel them becoming damp, and continue to do so until the papers are completely dry for 24 hours. Once the discs have dried and feel hard to the touch, they can be used immediately or stored in freezer bags for up to a year.