5 ½ cups blackberries or raspberries
2 teaspoons lemon juice
1 1/4 cups sugar
1 egg yolk
1/2 light sour cream
1 1/2 whipping cream
Reserve 1/2 cup berries for garnish.
In food processor or blender, purée remaining berries. Press through sieve into bowl to remove seeds and make about 2 cups. Stir in lemon juice.
In top of heatproof bowl over simmering water, stir 1 cup of the purée with 1 cup of the sugar. Add eggs and egg yolk; whisk for about 10 minutes or until thick enough to leave trail after whisk is pulled through the bowl. Let cool to room temperature. Fold in sour cream.
Whip cream until firm; fold into purée mixture. Pour into plastic wrap-lined 9x5-inch loaf pan; cover with plastic wrap.
Freeze for at least 8 hours or until solid. In food processor or blender, blend reserved purée and remaining sugar until sugar is dissolved. Uncover terrine and loosen at ends using hot knife; invert onto platter. Remove pan and plastic wrap. Slice using hot dry knife. Pool sauce onto plates; top with terrine. Garnish with reserved berries.