Host: "For today's challenge, we would very much like you to bake twelve rye rolls. They must be beautifully presented and above all else, they must be identical."

Paul Hollywood: "Rye bread has gained in popularity as a healthy alternative to wheat. But the flour's low gluten content could present a real challenge to our bakers."

Mary Berry: "Rye is extremely difficult flour to work with because it has less gluten. It's very tricky because you really have to work that protein to build the gluten up, to create the sacks that the air will sit inside. Many of the bakers will be adding black treacle, honey and even cocoa, because they want it to be dark. But the real danger is when they glaze it and it gets too dark before the middle is done. It's tempting to take it out of the oven too soon."