Professional chefs measure the sugar content of ice cream and sorbet using a hydrometer. Too much or too little sugar and the ice cream won’t thicken properly. You can perform an easy test on your liquid mixture at home before putting it in the ice cream maker. Instead of a hydrometer, use an egg still in the shell. Wash the egg with a little soap and water to eliminate the risk of salmonella.
Put the clean egg into the liquid ice cream base before adding sugar. It will probably sink. Remove the egg and add a little sugar, stirring to dissolve. Put the egg back in. Repeat this procedure until the egg floats enough to show about a nickle-size portion of the shell. This means that you have the right amount of sugar in your mixture. If the egg floats so high that it turns on its side, you have too much sugar and your liquid may not thicken properly.