Cooking with rotten tomatoes can be dangerous because spoilage is not just about “bad taste” it can involve harmful microbes and toxins that heat may not fully destroy.

When tomatoes go rotten, they can grow bacteria, mold, and yeast. Some of these produce toxins that can make food unsafe even if you cook it thoroughly.

Here’s why it can be risky:

1. Bacteria and toxins
Some bacteria that grow in spoiled food can produce toxins. These toxins can cause food poisoning symptoms like stomach pain, vomiting, and diarrhea. In some cases, they are not fully removed by cooking.

2. Mold growth
If you see fuzzy spots (green, white, or black), that’s mold. Mold doesn’t just stay on the surface it can spread deeper into soft foods like tomatoes. Some molds can produce harmful substances called mycotoxins.

3. Hidden spoilage
Even if you cut off the bad part, the rest of the tomato may already be contaminated. Soft, leaking, or smelly tomatoes are usually fully spoiled.

4. Risk increases with storage time
The longer tomatoes sit at room temperature or in poor storage conditions, the more microbes multiply, increasing the risk of illness.

Bottom line
If a tomato is rotten, soft with a bad smell, leaking, or moldy, it’s safer to throw it away completely. Cooking does not always make spoiled food safe again.