How to make soft popsicles

I love to make popsicles out of store bought yogurt. They stay creamy and are delicious in any yogurt flavor.

A great choice for that is adding alcohol, as long as everybody eating them can also imbibe. Since pure alcohol resists freezing until it's as cold as -114°C (-173.2°F), it doesn't take a whole lot of alcohol to inhibit popsicles from freezing hard. A great list of recipes for use as a guide can be found here.

The main factors are a gelling agent, alcohol, sugar and air/stirring.

• Sugars may decrease the freezig point - add enough sugar and your ice remains soft-ish. Unfortunately this can mean your ice gets too sweet. So instead of using plain sugar, add some "inverted sugar": glucose syrup (aka corn syrup), which stays runny and doesn't crystalize.
  You could even take it up a notch and use trehalose, which is basically two linked glucose molecules. It is used in ice-cream making to inhibit the formation of ice crystals. It tastes also less sweet than regular sugar, allowing for less sweet ice cream. Find an award-winning sample recipe here (further down). And if you really must have some hard science, a study on the use of trehalose in ice cream.

• Alcohol has a low freezing point. But apart from the question whether you want to use it at all, you should note that you need a certain amount of ethanol to have a noticeable effect - high-proof alcohol and yes, you will taste it.

• Glycerine (a sugar alcohol) helps keep ice cream soft.

• Likewise the addition of gelling agents may inhibit the formation of ice crystals - locust bean gum is often used to replace eggs in custard-based ice cream and agar agar and pectin may serve a simmilar purpose.

• And finally you can mechanically avoid / hinder the formation of large ice crystals by churning your juice first and freezing the slush instead of pouring the juice straight in the molds. The ice will still be rather hard, but not as much of a "solid icicle", especially if combined with one of the additives above.

Simply adjusting (increasing) the sugar level will do it, and/or other things that interfere with crystal formation, such as pectin (either use some jelly/jam in making the mixture, or add pectin sold for making jelly/jam to your mixture.)

I'd encourage doing some practical tests where you add known amounts of sugar to your mixture until you find a level that works for the texture you want. If your juice label tells you how much sugar it has per volume, try adding sufficient sugar to have 30g/100ml as a "typical known to work" level - but you may want to aim higher or lower based on personal preference.

If you have rock hard pops, just let them set out for a few minutes. They will develop desired texture.