I completely understand your frustration with wasting food, Brenda, but in this case, the jar is dangerous and cannot be salvaged under any circumstances. Please do not taste or consume any part of this batch.
A domed or bulging lid on a canned jar is a textbook warning sign that gas-producing microorganisms are actively growing inside. Mushrooms are low-acid foods that grow directly in soil, which makes them particularly susceptible to Clostridium botulinum spores. When stored in an airtight container at room temperature without sufficient acidity or industrial-grade pressure processing, these spores can multiply and produce botulinum neurotoxin. This toxin is odorless, tasteless, and potentially lethal even in microscopic amounts. No amount of re-boiling, re-salting, or cooking can guarantee the safety of food that has already spoiled under these conditions.
To dispose of the jar safely:
1. Do not open the jar. Opening a pressurized, contaminated jar can splatter spores or toxins onto your skin, clothing, and kitchen surfaces.
2. Place the sealed jar directly into a heavy-duty plastic trash bag, tie it tightly, and then seal it in a second bag.
3. Place the bag straight into an outdoor garbage container where pets and wildlife cannot access it.
4. Wash your hands thoroughly with soap and water after handling the container.
For future batches, keep in mind that traditionally salted mushrooms require continuous cold refrigeration in a strong brine, rather than shelf storage at room temperature, unless you are using an officially tested pressure-canning recipe. When it comes to low-acid home preserves, the safest rule of thumb is always: when in doubt, throw it out.
