While a cast iron bathtub may have some similarities to a Dutch oven in terms of material, it is not suitable or recommended for use as a cooking vessel, especially for making bread or other food items.
Here are a few reasons why a cast iron bathtub should not be used as a Dutch oven for bread-making:
Sanitary Concerns: Bathtubs are designed for bathing, not for food preparation. They are not manufactured with the same sanitary standards as cooking equipment. Using a bathtub for cooking purposes can introduce a range of hygiene issues, such as bacteria or chemical contaminants that could be harmful if consumed.
Size and Shape: Cast iron bathtubs are typically large and have a shape that is not conducive to baking bread. The size and shape of a bathtub would make it difficult to create and maintain the proper conditions for baking bread evenly. The heat distribution and airflow in a bathtub would be significantly different from that of a Dutch oven, leading to inconsistent results.
Oven Compatibility: Cast iron bathtubs are not designed to withstand the high temperatures of an oven. They can crack, warp, or even release harmful fumes if subjected to extreme heat. Dutch ovens, on the other hand, are specifically made to withstand high oven temperatures and provide even heat distribution.
If you're looking to bake oversized loaves of bread, it's best to use appropriate baking equipment, such as a large Dutch oven or a baking stone, which are specifically designed for this purpose. They will provide the necessary heat retention, moisture retention, and even baking environment required for baking bread effectively.