The clearest sign that pekmez (grape or mulberry molasses) has gone bad is white, green or black mould on the surface, or its usually sweet-sour aroma turning sharply sour. Because it is so high in sugar, pekmez is naturally long-lasting, but that window shortens once the jar is opened and stored the wrong way.
How can you tell mould from fermentation?
If you see a fuzzy, spotted layer of mould at the rim or on the surface, the pekmez should not be eaten — mould is never limited to the visible patch, so scraping it off with a spoon is not a safe fix. Even without visible mould, if you feel gas escaping or a light fizz when opening the lid, the sugar in the pekmez may already be fermenting, and the taste will have shifted noticeably sour as well.
What do texture and colour changes tell you?
Fresh pekmez is thick but pourable; over time the top can harden slightly while the bottom stays looser, and stirring it back together fixes that — it does not count as spoilage. But if the texture unexpectedly thins out, the colour turns from dark brown to almost black, and an off smell comes with it, the product is no longer safe.
Some homemade batches that were not boiled down long enough end up with a lower sugar concentration, and that kind of pekmez can ferment far sooner than a commercial one; foaming within the first 2-3 weeks usually points back to that undercooked batch.
How long does it keep safely?
An unopened, sealed jar kept in a cool pantry can last a year or two without any issue. Once opened and left at room temperature, that window drops to a few months; an open jar kept in the fridge stays safe for around 6-8 months. Closing the jar with a clean spoon after every use, and keeping water or anything damp out of it, cuts the risk of mould dramatically.
In short, the real warning signs in pekmez are mould, escaping gas and a distinct sour smell; a hardened top layer or a slightly darker colour on their own are just normal ageing and do not make it unusable.
Is there a difference between grape, mulberry and carob pekmez?
Grape pekmez tends to have the highest sugar content, which usually gives it the longest shelf life; mulberry pekmez has a slightly higher natural acidity, so it is best used within 4-5 months of opening, since souring can start earlier than with grape pekmez. Carob pekmez, being darker and thicker, resists moisture better than grape or mulberry.
Whatever the type, a thin film that forms near the jar's rim is not always a sign of spoilage; it can simply be crystallised sugar on the surface, which breaks apart easily with a spoon, whereas real mould stays stuck to the surface and does not break up that way.
The jar's material also affects how well pekmez keeps; metal lids on glass jars can rust over time, so a plastic-lidded or vacuum-sealed jar is the better choice if the pekmez will be stored for a long stretch.
Attention Reader
This content is for information only and is not a substitute for medical advice. Consult your doctor before making any decision about your health.
Comments (1)
Ev yapımı pekmezim 3. haftada köpürmeye başladı, yazınızdaki gibi kaynatmayı yeterince yapmamışım demek ki. Buzdolabına aldım ama 6-8 ay dayanır mı emin değilim, şimdiden hafif ekşi bir koku almaya başladı.