Complex sentence: Alfred Bird's first major invention was egg free custard (1837) by using cornflower instead of egg, Alfred Bird created a high quality custard mix. It was originally intended only for his wife Elizabeth who had both egg and yeast allergies.
Split into simpler sentences: Alfred Bird's first major invention was egg free custard (1837). Using cornflower instead of egg, Alfred Bird created a high quality custard mix. It was originally intended only for his wife Elizabeth who had both egg and yeast allergies.