Metal can indeed interfere with fermentation, particularly in the case of highly acidic ferments. When the acidity of a ferment increases, it can cause metals to corrode and leach into the food or beverage being fermented. This can have negative effects on both the taste and safety of the final product.
One of the main concerns with metal vessels is the potential for the leaching of harmful substances into the ferment. Metals such as lead, copper, and aluminum can react with the acids in the ferment, leading to the release of metal ions into the liquid. These ions can then be ingested when consuming the ferment, which can be harmful to our health.
In addition to the potential health risks, metal leaching can also impact the taste and appearance of the ferment. The presence of metal ions can alter the flavor profile, resulting in a metallic or off-putting taste. It can also cause discoloration or changes in the color of the ferment, which may not be visually appealing.
To avoid these issues, it is generally recommended to use glass or stainless steel vessels for fermentation. Glass is non-reactive and will not leach any unwanted substances into the ferment. Stainless steel is also a good option, as it is resistant to corrosion and does not react with acidic foods or beverages.
Personally, I have experienced the negative effects of metal interference in fermentation. In one instance, I attempted to ferment sauerkraut in a metal container, and over time, I noticed that the kraut had a metallic taste and a strange color. This was a clear indication that the metal had interacted with the acidic cabbage, resulting in an unpleasant and potentially unsafe ferment.
Using metal vessels for fermentation can be risky due to the potential for metal leaching into the ferment. It is best to stick to glass or stainless steel vessels to ensure the safety and quality of your ferment.