Your butter likely tastes fishy due to oxidation (fat breaking down) from age or poor storage, absorbing odors from other foods like fish in the fridge, or issues from the cream's quality (like over-ripening or pasteurization), all leading to off-flavors and rancidity. If it smells or tastes bad, it's best to toss it, as it's likely spoiled, though a little bit of rancid butter usually won't make you sick.
I concluded after reading that article that the fishy smelling butter that has plagued me for over a month now is because of overripened cream, cream high in acid, and oxidized cream and butter.
Spoiled butter can smell (or taste) sour or tangy, and can change in color and texture. Mold or colored spots are a clear indication that butter has gone bad, but even a subtle shift from pale yellow to dark is a sign that it's time to throw it out.
The first clue that your butter has gone bad will be the smell. Any sour or off-putting smell means it's a goner. Same goes for taste: If it tastes sour or off, toss it out.
A fishy taste in reflux can result from bile reflux, where digestive fluids flow back into the esophagus. This differs from typical acid reflux and may cause a bitter or unusual taste. Triggers include fatty foods, certain medications, or delayed stomach emptying.
During normal digestion, the food you eat is broken down into its various chemical components. In foods like fish, eggs and beans, these components include trimethylamine-N-oxide (TMAO). As TMAO is broken down, it produces a pungent chemical called trimethylamine, the same chemical that gives fish its distinctive odor.
The lowdown
Yes, a bitter taste in your mouth can indicate liver problems. It can also indicate several other issues, such as kidney disease, dry mouth, and acid reflux. If you experience a metallic taste in your mouth, you should talk to your doctor for proper diagnosis and treatment.
Eating expired butter is generally harmless but can cause temporary digestive discomfort, like vomiting or diarrhea, due to its nasty taste. Butter is less likely to harbor harmful bacteria due to its high fat content. The salt in salted butter also helps keep out microbes.
TRUST YOUR SENSES: LOOK, SMELL, AND TASTE BEFORE YOU WASTE
Look at it: if you notice any mold or discoloration, it's best to throw it out. Next, smell it. Fresh butter has a mild, creamy scent. If it smells sour or rancid, it's time to discard it.
A lack of flavor could also indicate the butter is past its prime, but has not yet spoiled. Butter that has become completely rancid will have a sour, funky, or bitter taste. (Don't worry—a little spoiled butter is not likely to make you sick.)
Unsalted butter can last up to three months in the fridge. (If the butter is unwrapped, shorten those projections to about two months in the fridge.) And in a cabinet or on the counter, you can leave butter out for a few days to a week without it spoiling.
Butter comes with a 'best before' date instead of an expiry date, but it can easily outlast that date by months if stored properly. As long as it doesn't smell or taste rancid, it is safe to use. Once it goes rancid, it will develop an off-putting flavor that will ruin any recipe you use it in.
A sour, musty, or otherwise off-putting smell (some have described it as sweaty feet) means it's past its prime. Butter that has gone bad will have a sour, bitter, or metallic taste.
A fishy taste from fish oil is a sure sign that it's started to oxidize, which is another way of saying it's gone rancid. That's bad news, because taking rancid oil isn't great for our health.
Unless you can see any visible signs of expiration or notice a sour, unpleasant smell, it's generally safe to use expired butter.
Sour or rancid smell: Fresh butter should smell clean, sweet, and creamy. Any sour, fishy, or soapy odors mean spoilage. Change in color: Spoiled butter may turn deeper yellow, develop translucent areas, or show hints of mold (usually green, blue, or white fuzz).
Butter also consists of at least 80% fat, and bacteria needs water to grow. Since butter is mostly fat, it creates a barrier that makes it almost impenetrable to bacteria. Another factor determining how long butter is safe to be left on the counter is the presence of salt.
Signs of Spoilage Look for a sour or rancid smell, discoloration, or mold growth. If butter shows any of these signs, it should be discarded. Conclusion In summary, salted butter can be safely left out for short periods, while unsalted butter should be refrigerated.
The symptoms usually start within 1 to 2 days after eating contaminated food. Symptoms can start between a few hours and a few weeks later. In most cases, these symptoms will pass in a few days and you will make a full recovery.
However, unsalted butter should be refrigerated to prevent spoilage. Storing Butter at Room Temperature General Guidelines Salted Butter: Safe to leave out for 1-2 days at room temperature, especially if your kitchen is cool (below 70°F). The salt acts as a preservative, helping to prevent spoilage.
Produce accounted for nearly half of illnesses, which were most often caused by norovirus. Meat and poultry were the most common sources of fatal infections, much due to Salmonella and Listeria.
Symptoms of acute liver failure may include:
Foetor hepaticus is a feature of severe liver disease; a sweet and musty smell both on the breath and in urine.
Pruritus is one of the most common symptoms experienced by patients with cholestatic liver disease. Pruritus associated with cholestasis is characteristically localized to the palms and soles, although generalized itching can also occur.
Viral infections like colds, flu or COVID-19 affect your sense of taste. Inflammation. Any condition that results in inflammation of your tongue can affect your taste receptors and your sense of taste. Metabolic disorders.