Celery can sometimes develop tiny black spots, raising questions about its freshness and safety. These spots may indicate natural occurrences, minor damage, or more significant issues like disease or pest activity. Understanding the causes helps determine if celery is safe to eat or should be discarded. This guide clarifies the different causes and offers practical advice.
Identifying the Cause of Black Spots
Black spots on celery stem from various issues, each with distinct characteristics. Recognizing these differences is key to understanding the celery’s condition.
Fungal Diseases
Fungal infections commonly cause black spots on field-grown celery. Early blight (Cercospora apii) appears as large, irregular, dark-brown spots on leaves and stems, sometimes with concentric rings. Severe cases can cause leaves to wither. Late blight (Septoria apiicola) shows as small, circular, tan spots on leaves and stems, often with tiny black dots (pycnidia) resembling pepper flecks.
Bacterial Issues
Bacterial problems, like soft rot, can cause dark discoloration. Soft rot begins as water-soaked lesions that turn brown or black. These spots are often accompanied by a soft, mushy, slimy texture and a foul odor, indicating advanced spoilage.
Pest-Related Residue
What appears as black spots can be residue from common garden pests. Tiny black specks may be insect droppings (frass) from pests like aphids or thrips. Aphids excrete honeydew, on which sooty mold often grows, creating black appearances. These superficial residues can usually be washed off.
Natural Discoloration and Bruising
Physical damage, bruising, or air exposure can cause natural discoloration. When celery is cut or bruised, oxygen exposure leads to browning. This results in localized dark spots that are usually dry and do not spread like pathogens. These spots are often found on cut ends or impacted areas.
General Spoilage and Mold
As celery ages, it can show general spoilage, including mold. Fuzzy, spreading black spots indicate mold. This spoilage often occurs when celery is stored too moist or too long. Mold growth may also include sliminess and an off-odor.
Is Celery with Black Spots Safe to Eat?
Whether celery with black spots is safe to eat depends on the cause and extent of discoloration. If spots are superficial pest residue or minor bruising, celery can be consumed after washing and trimming. Simply wash off insect droppings or sooty mold, and cut away bruised areas.
However, if spots indicate fungal or bacterial diseases, or widespread mold, discard the celery. Celery with bacterial soft rot (mushy, slimy, foul-smelling black spots) should be thrown out. Likewise, discard celery with fuzzy or spreading mold, extensive discoloration, softness, or an off-smell. Significant spoilage affects taste, texture, and can lead to illness.
Preventing Black Spots and Proper Storage
Prevent black spots by careful selection and proper storage. When buying, choose bright green, firm, crisp stalks, avoiding yellow, brown, or spotted ones. Leaves should be vibrant, not wilted.
To extend freshness, avoid washing celery until just before use, as moisture encourages bacterial growth. For whole, unwashed celery, wrap it snugly in aluminum foil and store in the refrigerator’s crisper drawer. This method helps retain moisture and prevents spoilage, keeping celery fresh for up to four weeks. For cut celery, submerge pieces in water in an airtight container in the refrigerator, changing water every other day; this maintains crispness for five days to a week. Storing celery in your crisper’s high-humidity zone is also beneficial.
When to Discard Celery
Discard celery when clear signs of spoilage indicate it is no longer safe or appealing. Immediately discard stalks with widespread, fuzzy mold or large affected areas. A slimy or mushy texture is another definitive sign of spoilage, often linked to bacterial growth.
Any strong, acrid, or foul odor means celery has gone bad and should be discarded. Extensive discoloration, like significant yellowing, browning, or deep black spots affecting integrity, indicates it’s past its prime. While slight limpness can be revived by soaking in ice water, very soft, bendable, or entirely un-crisp celery should be discarded.