There is no straightforward answer to whether an old sourdough starter is better than a young starter culture, as there are advantages and disadvantages to both.
A sourdough starter is a mixture of flour and water that has been left to ferment naturally, capturing wild yeast and bacteria from the environment. The longer a sourdough starter is maintained, the more complex its microbial community becomes, which can result in a more developed flavor and texture of bread. However, a very old starter may also become less active, making it difficult to rise bread properly.
On the other hand, a young starter culture may have a less complex microbial community, but it is generally more active, which can make it easier to work with and produce consistent results. However, because the microbial community has not had as much time to develop, the bread produced with a young starter may have a less distinct sourdough flavor.
Typically, a young starter has a milder flavour. After a while age delivers a more tangy taste. However, after a while, it levels out and becomes consistent.
Ultimately, the choice between using an old or young sourdough starter may depend on personal preference and the specific recipe being used. A baker may experiment with different starters to determine which produces the desired flavor, texture, and rise for their bread.