Drinking expired coffee may not make you sick, but it likely won’t taste very good. How long coffee lasts depends on how it is stored. Unopened coffee can last 6-12 months past its “best by” date if stored properly. Once opened, coffee lasts 3-5 days if refrigerated. If not refrigerated, opened coffee only lasts 12-24 hours before going stale.
Can expired coffee make you sick?
Coffee contains natural acids that act as preservatives and prevent bacterial growth. This means that drinking expired coffee is very unlikely to make you sick. However, coffee’s flavor and aroma compounds start to degrade soon after roasting. So while expired coffee won’t hurt you, it will start to taste bitter and stale quickly after opening.
How does coffee expire?
Coffee expires due to oxidation and loss of volatile aromatic compounds. Oxygen causes coffee beans and grounds to go rancid over time. Heat, light, and moisture speed up this process. Additionally, coffee’s aromatic compounds that provide flavor and aroma are volatile, meaning they evaporate easily. Keeping coffee sealed in an airtight container helps extend its shelf life.
Signs your coffee has expired
The most noticeable sign your coffee has expired is a flat, bitter, or stale taste. The vibrant, complex flavors and aromas of fresh coffee deteriorate quickly. Other signs of expired coffee include:
- Light coffee color
- Papery or cardboard aroma
- Lack of crema on espresso
- Oil slick visible on the surface
How to store coffee properly
Proper storage helps maximize coffee’s freshness and shelf life. Follow these tips for storing coffee:
- Keep coffee sealed in an airtight container or bag. Oxygen is coffee’s worst enemy.
- Store coffee at room temperature. Refrigeration can cause condensation.
- Keep coffee away from heat, light, and moisture. This accelerates staling.
- Buy coffee in smaller batches more frequently for ultimate freshness.
- Do not freeze coffee beans. Freezing damages their cellular structure.
- Store coffee off the counter and pantry shelf. The counter is too warm, while the pantry may be humid.
How to store whole bean vs. ground coffee
Whole coffee beans maintain freshness longer than pre-ground coffee. Whole beans have less surface area exposed to oxygen. Follow these guidelines:
- Whole beans stay fresh for 6-12 months sealed at room temperature.
- Pre-ground coffee keeps for 3-5 days maximum in the refrigerator.
- Use ground coffee immediately for optimal flavor.
Does expired coffee make you poop?
Coffee’s laxative effect has nothing to do with whether it is expired or not. Fresh and expired coffee contain the same amount of caffeine and other compounds that stimulate bowel movements. A cup of expired coffee will be just as likely to make you poop as a fresh cup.
Why does coffee make you poop?
Coffee stimulates bowel movements through several mechanisms:
- Caffeine – Caffeine increases gastrin, triggering peristalsis. It also relaxes the anal sphincter muscle.
- Chlorogenic acids – These compounds stimulate gastric acid secretion and colon motility.
- Milk/cream – Dairy containing lactose can cause diarrhea in lactose intolerant people.
- Volume – Fluid volume stretches the colon, triggering contractions.
These laxative components are present fresh or expired coffee. Short-chain fatty acids that readily absorb and provide energy to colon cells are also abundant in coffee.
Tips to avoid coffee-induced diarrhea
To avoid having coffee make you poop, try these mitigation strategies:
- Reduce portion size – Have just one small cup instead of a large portion
- Choose dark roast – Higher roasting reduces laxative chlorogenic acids
- Limit added dairy – Use non-dairy milk or black coffee
- Eat something – Having coffee with food buffers its effects
- Stay hydrated – Make sure you are drinking enough water
- Wait it out – Effects diminish with consistent daily consumption
Should you drink expired instant coffee?
Instant coffee has a longer shelf life than ground coffee, but its flavor still deteriorates after opening. Unopened instant coffee can last 9-12 months past its “best by” date. But once opened, it may only last 3-4 weeks before expiring.
How to spot expired instant coffee
Signs your instant coffee has expired include:
- Bitter, flat, or “off” taste
- Weak coffee color
- Powder clumping
- Loss of aroma
- Grainy or chalky dried powder
Proper storage of instant coffee
Follow these tips to extend instant coffee’s shelf life:
- Keep powder very dry and sealed from air and moisture.
- Store at cool room temperature.
- Keep away from heat, sunlight, and strong odors.
- Transfer to smaller jar once opened.
- Use clean, dry spoon to scoop to avoid contamination.
What happens if you drink rancid coffee?
Rancid coffee that has severely oxidized or spoiled beyond just staleness is not necessarily dangerous, but it can cause some unpleasant effects if consumed. Side effects of drinking rancid coffee may include:
- Upset stomach
- Nausea
- Vomiting
- Diarrhea
- Abdominal pain
- Unpleasant taste
- Bad breath
These effects are generally temporary and subside once the rancid coffee is out of your system. Rancid coffee is unappetizing but drinking it in small amounts is not toxic. Still, it is best avoided.
How can you tell if coffee is rancid?
Signs that coffee has severely spoiled and become rancid include:
- Soft or slimy coffee beans
- Strong bitter, sour, or rotten flavor
- Moldy, dark spots on beans
- Extreme dryness or oiliness
- No coffee aroma
- Ammonia-like smell
Coffee that smells or tastes chemically or rotten should be discarded. Things that cause rancidity include extreme heat, sunlight, humidity, and very old age.
How to avoid rancid coffee
Prevent your coffee from going rancid by:
- Checking for signs of spoilage before use
- Storing coffee properly in an airtight container
- Always smelling coffee before brewing
- Discarding extremely oily or dried out coffee
- Buying coffee frequently in small amounts
Is it dangerous to drink moldy coffee?
Yes, drinking coffee contaminated with visible mold introduces potentially harmful toxins and bacteria into your body and should be avoided. Mold in coffee occurs when beans get exposed to moisture and heat.
Health risks of drinking moldy coffee
Dangers associated with consuming moldy coffee include:
- Myotoxins – toxic compounds that can cause organ damage and negative health effects
- Aflatoxins – carcinogenic substances that are toxic to the liver
- Ochratoxin A – possible human carcinogen
- Fungal infections – ingesting spores may cause gastrointestinal or respiratory issues
Mold can thrive easily in the hot, humid coffee-making process. Always inspect beans and discard any moldy grounds.
How to prevent moldy coffee beans
To keep mold out of your coffee, be sure to:
- Check beans for dark spots or fuzz
- Use clean water for brewing
- Thoroughly dry wet grounds
- Clean coffee machine to prevent buildup
- Store beans in an airtight container
- Buy in small amounts and use quickly
Can you salvage slightly moldy coffee beans?
If your coffee only has a small amount of surface mold, you may be able to rescue the unaffected beans by:
- Discard any beans showing mold
- Hand sort through remainder to remove moldy bits
- Spread beans in single layer on baking sheet
- Bake at 200°F for 30 minutes to kill spores
- Allow to cool and transfer to airtight container
- Use beans within 2-3 days
However, beans with any amount of internal mold should be discarded fully. Mold can leave behind toxins even after removal.
Does expired coffee cause caffeine poisoning?
No, drinking expired coffee does not increase the risk of caffeine overdose or poisoning compared to fresh coffee. Caffeine content remains stable as coffee expires, so old coffee contains similar amounts of caffeine as a fresh batch brewed the same way.
Caffeine content of coffee
| Brew Method | Serving Size | Caffeine |
|---|---|---|
| Drip coffee | 8 oz (240 ml) | 70-140 mg |
| Black tea | 8 oz (240 ml) | 25-60 mg |
| Espresso | 1 oz (30 ml) | 63-91 mg |
Caffeine levels vary based on coffee type, roast, grind size, and brew method. But expired coffee contains the same caffeine as fresh.
Caffeine overdose symptoms
Consuming too much caffeine can cause:
- Jitters, anxiety, insomnia
- Fast heartbeat, palpitations
- Dizziness, tremors
- Headaches
- Upset stomach, diarrhea
- Irritability
Overdose occurs at very high doses. Expired coffee is not more likely to deliver toxic caffeine levels. But moderation is still advised.
Tips to prevent overdose
Stick to 400mg daily at most and avoid toxicity by:
- Measuring coffee grounds
- Limiting cup size
- Choosing low-caffeine beans
- Drinking decaf
- Not exceeding 4 cups daily
Does expired coffee contain fewer antioxidants?
Yes, antioxidant levels in coffee decline as it gets older, especially after roasting and opening. Coffee beans contain powerful polyphenol antioxidants that provide health benefits.
Antioxidants found in coffee
The major antioxidants in coffee include:
- Chlorogenic acids – SCAs and CQAs
- Caffeic acid
- Hydrocinnamic acids
These polyphenols have anti-inflammatory, anti-diabetic, anti-cancer, and antihypertensive properties. However, they break down over time with exposure to air, moisture, and high temperatures.
Health benefits of coffee antioxidants
Potential beneficial effects associated with coffee antioxidants include:
- Lowered risk of heart disease, stroke, and diabetes
- Reduced inflammation
- Improved brain function
- Protection against liver and colon cancer
- Better cholesterol levels
Maximize antioxidants by drinking coffee within a week of roasting before degradation occurs. Minimize oxidation by storing beans properly.
Does expired coffee become toxic?
On its own, coffee does not turn toxic or create dangerous chemicals as it expires. However, expired coffee may grow mold if subjected to moisture, and some molds produce toxic mycotoxins that can cause health issues if consumed.
Toxins found in contaminated coffee
Moldy coffee may contain hazardous mycotoxins such as:
- Aflatoxin B1
- Ochratoxin A
- Fumonisin B1
Roasting helps kill pathogens, but coffee beans can become recontaminated if stored improperly. Visually inspect beans before brewing and discard any with signs of mold.
Other potentially toxic compounds
Coffee naturally contains small amounts of acrylamide and hydrogen peroxide produced during roasting. However, levels are too low to be dangerous. Heavy metal contamination may also occur if beans are dried on dirty ground or irrigated with contaminated water.
Tips to prevent toxic coffee
Avoid potentially toxic coffee by:
- Using purified or filtered water
- Washing beans during processing
- Discarding moldy or damaged beans
- Storing coffee dry and sealed
- Limiting metal exposure during growing/drying
Conclusion
Drinking expired coffee that has merely gone stale from sitting around too long is not ideal but is unlikely to make you sick. However, coffee left open too long may develop mold or rancidity that can cause health issues. Storing coffee properly helps preserve freshness and prevent deterioration in quality and safety.
While expired coffee may not be toxic on its own, severe degradation may introduce mold toxins, dangerous bacteria, or other contaminants. Always inspect coffee before brewing and discard any that smells, looks, or tastes off. Drink expired coffee at your own risk, but consuming rancid, moldy, or improperly stored coffee is best avoided.
