Sorbets are a bit like good friendships and general happiness… balance is required to achieve success.
Too sweet and they can be off-putting. Not sweet enough and they can be hard-edged… icy. Artificially sweet… not really interested in pursuing. Well... you get my drift. Apart from the flavor profile you’re going after, the right level of sweetness is critical to producing a sorbet that will be both texturally and tastefully pleasing.
The good news is that anywhere in that balance zone, the flavor will be great and… truly… from a purely personal perspective, anywhere in the granita to sorbet zone will produce a light, satisfying, refreshing dessert.
Since I’ve become fairly obsessed with the generous sprinkling of lime zest on virtually any cut and combination of fresh fruit, this watermelon-mint-lime zest profile is particularly pleasing. The subtle mint infusion of flavor (and sweetening) is introduced in the form of a simple syrup. In this prep, it’s a 50:50 ratio of sugar and water infused with a good bit of mint leaves that I muddle just a tad as the mixture heats up… dissolving the sugar and resulting in a thin syrup. The watermelon just gets whirred up separately in a blender. Then these two components get popped into the fridge overnight (or freezer for a few hours if time is a factor) so that everything is good and cold before getting introduced to your ice cream/sorbet machine. (Just make sure both of these “mixes” are housed in non-reactive containers to cool.)
Then comes the mixing… getting your fruit blend sweetened up just right to please the palate and the spoon. Tasting is always a good test. However, with sorbet, going a bit sweeter is often better as it will temper a bit once it gets its time in the freezer. So what's sweet enough? Too much sugar and your sorbet won't freeze correctly; not enough sweetener and your sorbet will freeze rock hard. Without purchasing technical gadgets to determine the right amount of sweetener to add (there's a whole technical side involving "brix" and such), an “egg test” is a good little barometer for the home cook (and kind of fun to do). More on this later.
First I add a good bit of zested lime to my watermelon blend. This base should be place in a bowl that is deep enough to allow an average size egg to sit at the bottom of your bowl with just enough head room to cover from view. Straining your simple syrup through a fine sieve (so as not to get leaves in your sorbet), begin adding some of your syrup to your watermelon blend. Then take a well-washed egg (yep, right from the fridge) and gently place it in the bottom of your bowl. If it doesn’t float up to reveal a nickel size bit of it through the top surface of your liquid then you need more sweetener. Continue adding the simple syrup and testing the egg float. Once the egg rises to view that nickel size portion through the surface of the watermelon blend in your bowl, then you are pretty much good to go. Taste it too… it should be on the sweeter side, but pleasing.
Since all your ingredients should still be good and cold, you can then proceed to “churning” in your machine… super cold ingredients into your ice cream/sorbet maker makes for a good churn. With mine (Cuisinart ICE-21), I just get the machine going (simple on-off switch) and then pour my mix slowly in as the machine is turning. It takes about 8 to 10 minutes to get a nice consistency. Place it in the freezer to firm up (the door is a good spot as it’s less likely to get overly hard there). You may have to leave it out to soften a bit before serving (10 to 20 minutes if it’s really firm). Or… churn and serve right away (going a bit beyond the 8 to 10 minutes… or when your machine cuts off telling you it’s ready). Always best to keep an eye on it to ensure its doing its thing correctly.
All in all, it’s so refreshing and light, beautifully flavored with the subtle, summer sweetness of watermelon, lightly infused with mint, and brightened with the lime zest. For an added little pop, add a bit more fresh lime zest overtop when serving… it won’t tip its delightful, welcoming balance one bit… making it a happy and enjoyable choice.