Blackberry jam base, with a granita and an ice cream drawn from it

Put eight cups of water and the sugar in a pot and bring to a simmer.

Add the blackberries and bring to a boil.

Granita: take off some of the sweet, watery blackberry syrup at this stage, pour it onto a metal tray and freeze.

Ice cream: after the base has reduced about 15 minutes, take about half a cup of berries and syrup into a small sauce pot with sugar.

Reduce about five minutes to an inverted sugar, to about 220F, so the water has boiled out; take off the stove and cool about 15 minutes.

Pour very cold cream into a bowl, add the warm syrup, and chill in the freezer about 30 minutes.

Jam: bring the remaining blackberry base to about 230F and let it cool before jarring; mash the berries into the syrup once moderately cooled.

Churn the ice cream base in the machine on setting two, from about 40F down to 32 or 31F.

Pack the churned ice cream into a container and freeze two and a half to three hours to set.

Scrape the frozen granita with forks into flavoured shaved ice; serve with fresh blackberries.

Optionally strain the berries for a seedless ice cream.