A traditional French baguette is made of flour, water, yeast and salt. It’s fascinating how these four simple ingredients produce a beautiful, flavorful, crusty baguette. What’s even more fascinating is how different bakers, using the same ingredients, can make baguettes that differ from each other quite substantially sometimes. Up to about a century ago making bread with natural leaven was the rule for bakers in France. Later it was a mix of natural leaven and baker’s yeast, which made the crumb lighter and more open. Lately, many bakeries seek efficiencies and switch to using baker’s yeast as using natural leavens requires more work.