Bloom the gelatin in ice water. Heat 125 ml of the yoghurt with the salt and add the bloomed gelatin – heat until dissolved.
Combine the gelatin mixture with the remaining 125 ml yoghurt while it is still warm. Place the mixture in a cream siphon gun and charge it twice. Let it set at room temperature for 1 hour. If it is runny when discharging, refrigerate until the mixture is the right consistency.