My friend was the pastry chef at a restaurant and forever used frozen berries for her coulis. When berries came into season, she started using fresh. But she was always disappointed. The texture wasn't as luscious. She switched berries. No luck. Eventually she tried the frozen berries again and voila! That did the trick. Fortunately she's also got some great connections and contacted the guy that ran Heston Blumenthal's lab. What's going on? There's a much larger explanation in my notes somewhere but the gist is, freezing breaks down the cell walls. From that point forward, even if she had fresh berries she intended to use for a coulis, ice cream etc, she froze the berries first.