Forgotten to soften the butter?

Grate butter coarsely, spread onto baking paper and stand for 10 minutes before using. Alternatively chop into 2cm cubes, microwave on 30% power in 10 second bursts until just softened. 

Making a sauce?

Enrich wine based sauces by whisking in a large knob of cold butter at the very end, it will give your sauce a richness, shine and round off any acidic flavours.