Condiments are everyday staples in Kiwi kitchens: tomato sauce on fish ’n’ chips, mayonnaise in potato salad, soy sauce splashed over takeaway noodles. But once a bottle is opened, it often ends up lingering in the fridge door or pantry for months, with many of us unsure whether it’s still safe or even worth keeping.
This guide breaks down how long popular Kiwi condiments last once opened, where to store them, what best-before dates really mean and the clear signs that tell you when it’s time to throw something out.
Best-before dates v reality
Best-before dates aren’t expiry dates. They indicate when the manufacturer expects a product to be at peak quality, not when it suddenly becomes unsafe. Many condiments remain fine beyond that date if they’ve been stored correctly and still look and smell as they should.
Two important caveats apply. If a condiment smells off, has changed colour dramatically or shows signs of mould, it should be discarded. And if it has been left at warm room temperature for long periods after opening when refrigeration is recommended, quality and safety can deteriorate more quickly.
Make your own
Fridge or cupboard? The simple rules
As a rule of thumb, most opened condiments benefit from refrigeration, particularly those that are creamy or low in acidity. High-acid or high-salt products such as vinegar, hot sauce, soy sauce and Worcestershire sauce are more stable and can usually be kept in a cool, dark cupboard.
Over summer, warmer kitchens can speed up deterioration, making refrigeration the safer option for many opened bottles and jars.
Kiwi favourite condiments, storage and how long they last
Tomato sauce
Storage after opening: Fridge
How long it lasts: 3–6 months
Tomato sauce is acidic and fairly robust. Common Kiwi supermarket versions, including Wattie’s, Heinz and own-brand sauces, are best kept in the fridge once opened to preserve flavour and prevent the surface from darkening or going sticky. If it smells yeasty or the colour has dulled significantly, it’s time to replace it.
Mayonnaise
Storage after opening: Fridge
How long it lasts: 1–2 months
Mayonnaise is oil-based and dairy-free, but it deteriorates quickly if left warm. Popular supermarket options such as Hellmann’s and Edmonds should always be returned to the fridge promptly after use. If the smell changes or separation looks unusual, it’s safest to bin it.
Mustard
Storage after opening: Pantry or fridge
How long it lasts: 6–12 months
Mustard’s acidity and spices make it one of the hardier condiments. This includes yellow, wholegrain and Dijon-style mustards sold under brands such as Colman’s and Edmonds. Yellow and wholegrain varieties cope well in the pantry, while creamier Dijon styles retain flavour better when refrigerated.
Soy sauce
Storage after opening: Pantry (fridge optional)
How long it lasts: 1–2 years
Thanks to its high salt content, soy sauce keeps well at room temperature. Many Kiwis store brands such as Kikkoman, Lee Kum Kee and own-label soy sauces in the pantry without issue. Refrigeration isn’t essential but can slow flavour loss and colour darkening, particularly in warmer months.
Sweet chilli sauce
Storage after opening: Fridge
How long it lasts: 6–12 months
Sweet chilli sauce is usually sugar- and vinegar-based, but once opened it lasts longest when chilled. Supermarket staples such as Trident and own-brand versions should be kept in the fridge. Puffy lids, bubbling or fizzing are signs of fermentation and mean it should be discarded.
Barbecue sauce
Storage after opening: Fridge
How long it lasts: 3–6 months
With its mix of tomato, sugar and vinegar, barbecue sauce resists spoilage, but refrigeration helps keep flavours bright. Whether it’s a classic supermarket bottle or a premium option like Whitlock & Sons, opened barbecue sauce is best kept chilled.
Worcestershire sauce
Storage after opening: Pantry or fridge
How long it lasts: 1–2 years
Worcestershire sauce contains enough salt and acid to remain stable at room temperature. Traditional versions such as Lea & Perrins, along with supermarket equivalents, can live in the pantry, though refrigeration helps preserve peak flavour.
Vinegar
Storage after opening: Pantry
How long it lasts: Indefinitely (quality may change)
Vinegar’s high acidity means it keeps almost indefinitely. This applies to white, cider and wine vinegars commonly sold in New Zealand supermarkets. Sediment or cloudiness, particularly in cider vinegar, is harmless. Heat and sunlight won’t make vinegar unsafe, but they can dull flavour over time.
Hot sauce
Storage after opening: Pantry
How long it lasts: 2–3 years
Hot sauce is one of the most stable condiments, thanks to its combination of chilli, vinegar and salt. From classics like Tabasco to sriracha-style sauces, most bottles can sit happily in a cupboard. Significant colour fading or a loss of aroma suggests it’s past its best.
Chutneys and relishes
Storage after opening: Fridge
How long it lasts: 6–12 months
Chutneys and relishes are rich in sugar and vinegar, which helps preserve them. From classic Branston pickle to local options, such as Barker’s or Anathoth, opened jars keep their flavour and texture best when stored in the fridge.
How to tell when it’s time to bin a condiment
Don’t rely solely on dates. Use your senses. Sour or unusual smells, mould, fuzz or bubbling all mean it’s no longer safe. If a condiment becomes oddly slimy or goopy, particularly mayonnaise or tomato sauce, it’s safer to replace it.
Top tip: Close lids tightly after use. Return condiments to the fridge promptly if recommended. Keep bottles and jars out of direct sunlight and heat. Wipe rims and lids to prevent contamination.
Condiments don’t last forever, but many outstay their best-before dates if stored well. With a few sensible habits and a willingness to trust your senses, you can keep your favourites tasting good and avoid unnecessary waste.
Herald contributor Nikki Birrell has worked in food and travel publishing for nearly 20 years. From managing your kitchen to cutting costs, she’s shared some helpful advice recently, including how to prep your barbecue for summer grilling, gourmet hacks for elevating budget ingredients and what toppings to choose for different crackers.