Fruit ice cream is where homemade most often loses to shop-bought, and the cause is simple: strawberries are around 90 percent water. Add a pound of fruit to a dairy base and you have added a large amount of water that will freeze into crystals you can feel.
The fix is not less fruit. It is taking the water out of the fruit before it goes in.
Macerate, then reduce
Sugar draws water out of cut fruit by osmosis — that is maceration, and thirty minutes does most of the work. Simmering the resulting syrup then drives more water off and concentrates the flavor. You end up adding intense strawberry and much less water, which is exactly the trade you want. Skipping this is the difference between strawberry ice cream and strawberry-flavored ice.
Why not just blend the fruit in?
You can, and it produces a smooth pink ice cream that tastes mildly of strawberry. Two problems. All the fruit water goes into the base, so it freezes harder and icier. And blended raw strawberry has a slightly flat, cooked-jam quality once frozen, because cold suppresses delicate aromatics.
Mashing most of the fruit and leaving some in pieces gives you both: flavor distributed through the base, and bites of actual fruit.
What the lemon juice is doing
Two jobs. It brightens the strawberry flavor, which freezing dulls — every frozen dessert tastes less intense than the same mixture at room temperature, so you compensate by seasoning more assertively than seems right when you taste the base. And a little acid helps the fruit hold its color rather than going brown-pink.
On frozen fruit pieces
Pieces of fruit in ice cream freeze harder than the ice cream around them, because they are mostly water with no fat. That is why supermarket fruit ice cream often has unpleasantly hard nuggets in it.
Two ways to soften them. Keep them in the macerating syrup rather than rinsing them, so they carry sugar into the freezer with them. And cut them small — a quarter-inch piece is pleasant, a whole halved strawberry is a frozen rock.
Can you use frozen strawberries?
Yes, and out of season they are often better than fresh, because they were picked ripe. Thaw them completely first and use the liquid that comes out of them as part of the syrup to reduce — there will be a lot of it, and that is water you want to drive off rather than add.
The method transfers to other fruit
Macerate, strain, reduce, combine. It works for peaches, raspberries, blackberries, cherries and mango. Adjust the sugar to the fruit's own sweetness, and for very watery fruit like melon reduce the syrup further.
If you want a pure fruit frozen dessert with no dairy at all, sorbet is the better target and much easier — there is no fat to protect and nothing to balance.
And if your last fruit batch came out icy despite all this, the full diagnosis is in why homemade ice cream is icy.
