Are homemade sauces, dips and dressings really cheaper? What the NZ supermarket maths shows

Is it cheaper to make your own pesto and other fridge or pantry staples? It depends ... we've done the maths to work out when to buy and when to make at home. Photo / Getty Images

With supermarket bills still stubbornly high, it’s tempting to assume that making pantry staples at home automatically saves money. Sometimes it does. Sometimes it doesn’t. The difference usually comes down to how often you cook, how much you waste, the pack sizes available in New Zealand supermarkets and how flexible you are with ingredients.

Here’s how the maths actually stacks up for everyday staples.

Breadcrumbs

Almost always cheaper homemade

A packet of dried breadcrumbs typically costs around $2–$4 at major supermarkets. But most households already throw away stale bread. Turning leftover slices or crusts into crumbs takes minutes and avoids waste entirely.

There’s no shelf-life catch either. Frozen breadcrumbs keep well for months without flavour loss.

Verdict: If you eat bread, homemade wins.

Salad dressings

Usually cheaper homemade

Basic vinaigrettes made from oil, vinegar and mustard almost always undercut bottled dressings per serve, especially if you already keep these staples in your kitchen. Bottled dressings often sit in the $4–$7 range for 250–300ml, depending on brand.

Where people lose money is jar size. Many oils and vinegars in New Zealand are sold in 500ml or premium glass bottles, which pushes up upfront spend. If you only make salad occasionally, a small bottle of ready-made dressing can work out cheaper overall.

Verdict: Cheaper if you already use oil and vinegar regularly.

Batch make a simple pasta sauce and you'll see the savings. Photo / Babiche Martens

Basic pasta sauce

Generally cheaper homemade

A mid-range jar of pasta sauce usually costs around $3.50–$6 per jar. A simple tomato sauce made from canned tomatoes, garlic and oil often works out cheaper per serve, especially when cooking for more than one person.

The cost advantage improves if you batch-cook and freeze portions. If you make a small one-off sauce using multiple fresh ingredients that don’t get reused, the saving narrows.

Verdict: Strong savings if you batch or cook regularly.

Make tacos a lot? Then the verdict's in – it's cheaper to make your own spice mix. Photo / Babiche Martens

Taco seasoning and spice mixes

Cheaper over time, not the first time

A supermarket taco sachet typically costs around $2.80–$3.20 for 30–35g and gives you one meal.

Buying paprika, cumin, chilli powder and oregano upfront can easily cost $10–$13 in total, which is more than one sachet. But each jar produces many batches. Once those spices are in your cupboard, the cost per homemade mix drops to cents rather than dollars.

The catch is shelf life. Ground spices keep peak flavour for roughly six to 12 months once opened. If tacos are a once-in-a-while meal, those jars may lose potency or go unused.

Verdict: Worth it for regular cooks. Sachets often make sense for occasional use.

Pesto

Depends heavily on jar sizes and ingredient choices

Small supermarket pesto jars commonly sit around $6–$9 for 190–200g, with premium versions costing more. Homemade pesto can be cheaper – but only if you shop strategically.

Two factors matter in New Zealand:

• Jar size reality: Pine nuts, parmesan and olive oil are often sold in relatively large or premium formats, pushing up upfront cost.
• Ingredient flexibility: Swapping pine nuts for cashews or almonds can significantly reduce the cost per batch.

If you grow basil, buy nuts in bulk or freeze extra portions, homemade pesto usually wins. If you buy premium ingredients just for one batch, it often doesn’t.

Verdict: Cheaper for frequent users and flexible cooks.

With hummus, it's the tahini that knocks up the homemade price. Photo / 123rf

Hummus

Sometimes cheaper, sometimes not

Small supermarket hummus tubs often cost around $4–$6 for 200–250g. Making hummus from dried chickpeas can be cheaper per serve – especially if you buy chickpeas in bulk.

Tahini is the wildcard. In New Zealand, it’s commonly sold in large jars at $6–$10+, which raises upfront cost. If you only use tahini occasionally, store-bought hummus can work out cheaper overall.

Verdict: Cheaper if hummus is a regular fridge staple.

Stock

Store-bought usually cheaper, homemade usually tastier

A 1-litre carton of stock typically costs around $2–$3, while stock cubes are even cheaper per serve.

Homemade stock almost always tastes better, with richer flavour and lower salt. But unless you already have bones and vegetable scraps available, buying ingredients specifically for stock can easily cost more than the supermarket option.

Verdict: Store-bought wins on price for most households. Homemade wins on flavour.

The real rule of pantry savings

Homemade pantry staples only save money when three things line up:

• You cook with them regularly.
• You use ingredients before flavour drops or spoilage sets in.
• You buy pack sizes that make sense for your household.

Ingredient flexibility also matters. Substituting cashews for pine nuts, using dried herbs instead of fresh or choosing store-brand staples can flip the “cheaper or not” verdict either way.

The smartest approach isn’t doing everything from scratch. It’s knowing which shortcuts quietly drain your grocery budget – and which ones are actually worth taking.

Herald contributor Nikki Birrell has worked in food and travel publishing for nearly 20 years.