How to Stop Herbs and Spices Clumping Together

It can't just be me – I come to use a particular jar of dried herb, spice or seasoning, to find it completely stuck together and impossible to get out. It's so frustrating, and seems to be worse with onion and garlic powder, which always seem to cake soon after the containers are opened.

This happens when moisture and humidity get into the container causing it to clump together and form a rock. Whilst the moisture will reduce the flavour and strength of the herbs, a lot of them you can re-invigorate by removing the moisture. Far less wasteful than throwing unused herbs and spices away.

How to remove the moisture

The easiest way is in the oven. I heat my oven to about 125C (250F) and use a metal skewer to get break the clump (or in this case garlic powder) out of the container, onto a sheet of baking paper, on a baking tray.

After just a couple of minutes, the heat will have removed the moisture, and I remove the tray and allow it to cool. Once cooled, I transfer it back into the container using a funnel and it now dispenses freely!

To prevent it happening again

Make sure the containers you store your dried herbs,spices and seasonings in are completely air-tight and always shut the lid/ close the container properly. Storing somewhere cool and dark (or even in the freezer!) will also help prevent moisture coming into contact with the inside of the container.

Avoid the temptation to shake the container directly into a pot of steaming food – this will allow moisture in. Spoon what you need out of the container, away from the stove top.

You can also add some dried beans or rice to the container to absorb any moisture and prevent the mixture from clumping.

Storing the containers upside down will also help prevent air getting in, making them last longer.

Why Some Spices Are More Prone to Clumping

Not all herbs and spices react the same way when exposed to moisture. Fine powders like onion powder, garlic powder, cinnamon, and ground ginger tend to absorb moisture far more quickly than coarser blends. This is because the finer the grind, the greater the surface area exposed to the air. Seasonings that contain natural sugars, like onion and garlic powder, are even more susceptible as sugar attracts and holds onto moisture. Blends with added salt can also clump faster, especially if the salt used is unrefined and retains trace minerals.

The Impact of Humidity in Australian Kitchens

Here in Australia, particularly in coastal or tropical regions, humidity plays a major role in spice spoilage. Even when your kitchen feels dry, the ambient moisture in the air can still creep into containers if they’re not properly sealed. During summer, when humidity levels peak and windows are more likely to be open, your spice rack can become a hotspot for clumping. Using a dehumidifier in your pantry or switching to moisture-resistant storage solutions can make a big difference in maintaining spice quality year-round.

How Long Do Herbs and Spices Actually Last?

While dried herbs and spices don’t necessarily “go off” like fresh produce, they do lose potency over time. Most ground spices stay fresh for around 6 months to a year, while whole spices can last up to 2 or 3 years when stored correctly. The issue with clumping is that it often signals early degradation caused by moisture, which speeds up flavour loss. If a spice no longer smells fragrant or tastes sharp, it’s probably time to replace it — regardless of its expiry date.

Reviving Clumped Spices Without Heat

If you don’t want to use your oven, there are a few gentler ways to rescue stuck-together spices:

• Use a blender or spice grinder: Transfer the clumped spice to a grinder or mini blender and pulse it back into a fine powder. Make sure the appliance is completely dry before use.
• Microwave method: Place the spice on a paper towel and microwave it in 10-second bursts. Stir between each burst and stop once the mixture is dry and loose again.
• Silica gel packs: Place a food-safe silica packet in your spice container to draw out moisture without the need for heat.

Choose the Right Storage Containers

The type of container you use has a huge impact on spice longevity. Glass jars with rubber-sealed lids are ideal, as they create a tight barrier against air and humidity. Avoid plastic containers with ill-fitting lids, as they allow moisture to seep in slowly over time. Dark or amber glass jars can also protect the spices from light exposure, which breaks down essential oils and dulls the flavour. If you're decanting bulk spices, label them with the purchase date so you can keep track of their age.

Best Practices for Refilling Spice Jars

When refilling your spice containers, avoid topping up old spices with new ones. It’s better to wash and dry the container completely before adding fresh product. Mixing old and new spices dilutes the flavour and increases the chances of contamination. Allow jars to air dry thoroughly before use to avoid trapping any residual moisture inside. This one small step helps keep your spices potent and clump-free for longer.

Bulk Buying Tips for Paleo Cooks

Buying spices in bulk can be cost-effective, but it does increase the risk of spoilage if you don’t store them correctly. Consider dividing bulk quantities into smaller airtight containers and storing the extras in the freezer or back of the pantry until needed. Only keep a small working jar in your spice rack, and refill as needed. This method also helps minimise exposure to light and heat — both of which degrade essential oils in spices, making them less effective in your cooking.

When to Replace Spices Entirely

Sometimes, no matter what you try, a spice just won’t revive. If it smells faint, looks faded, or tastes flat even after drying and grinding, it’s probably beyond saving. A spice that has turned musty or sour in scent may have absorbed too much moisture or begun to spoil. In these cases, it’s safer and more effective to replace it. Fresh, vibrant herbs and spices are crucial for paleo recipes where seasoning and wholefood flavours do the heavy lifting.

Simple Paleo Spice Blends to Make at Home

One of the best ways to ensure your spices stay fresh is to make your own blends in small batches. Here are a few paleo-friendly mixes that are easy to prepare and less likely to clump when stored correctly:

• Simple Meat Rub: Paprika, cumin, garlic powder, salt, pepper, and dried oregano.
• Herbed Roast Mix: Dried thyme, rosemary, sage, onion powder, and cracked black pepper.
• Curry Base Blend: Turmeric, ground coriander, cumin, cinnamon, ginger, and fenugreek.

Mix only what you need and store in small, airtight jars in a dark, cool cupboard. This way, you're always using fresh, fragrant blends that bring out the best in your paleo meals.

Stay One Step Ahead of Clumping

With just a few simple adjustments, you can dramatically reduce spice waste in your paleo kitchen. Whether it's storing containers upside down, adding moisture absorbers, or transferring clumped powders into the oven for revival, the key is prevention. Keep your herbs and spices dry, cool, and well-sealed — and you’ll never have to chip away at a garlic powder boulder again. A little care goes a long way toward keeping your cooking full of flavour and your ingredients as vibrant as your lifestyle.