Preserving Herbs: Drying, Freezing, Oil & Herb Vinegar

Fresh herbs in summer – but what about winter? If you grow your own, you face the pleasant task of preserving the harvest. The good news: preserving herbs is easy, needs little equipment, and pays off enormously. This article covers all the tried-and-true methods – from drying to herb oil.

Which Method for Which Herb?

Not every method suits every herb. As a rule of thumb:

Method 1: Drying

Drying is the oldest and simplest preservation method. Properly dried, herbs stay aromatic for 1–2 years.

Air Drying (Classic)

1. Harvest the herbs early in the morning – after the dew has gone but before the sun disperses the essential oils
2. Tie into small bundles (not too thick – risk of mold!)
3. Hang upside down in a warm, airy, dark spot
4. Dry enough to store after 2–4 weeks

Ideal conditions: 25–35 °C, good air circulation, no direct sunlight (fades color and aroma)

Drying in the Oven (Fast)

• Spread the herbs on parchment paper
• Dry at 30–40 °C with the oven door slightly ajar
• Duration: 1–3 hours depending on water content

Tip: Use the fan/convection setting – it promotes even drying

Food Dehydrator

Worth the investment for larger amounts: constant temperature (35–40 °C), multiple trays at once, low energy use. Herbs are ready in 2–6 hours.

Storage

Put dried herbs into airtight, dark jars. Don't store them above the stove (moisture!). Label with the date. Check the aroma before cooking by rubbing between your fingers – faded scent means it's time to replace.

Method 2: Freezing

Freezing preserves color and fresh flavor better than drying – ideal for herbs like parsley and basil, which lose a lot when dried.

Simple Freezing

1. Wash the herbs, dry them well (water = freezer burn)
2. Roughly chop or leave whole
3. Put into freezer bags or containers – as flat as possible
4. Take out in portions as needed

Ice Cube Method (Especially Handy)

1. Finely chop the herbs
2. Fill into ice cube trays
3. Top up with water or olive oil
4. Freeze, then transfer into freezer bags

Advantage: Portion control, straight into the pan – no thawing needed

Freezing Herb Butter

Mix softened butter with chopped herbs, roll in parchment paper (like a log), freeze. Just slice off a round when cooking.

Method 3: Herb Oil

Homemade herb oils make great kitchen gifts and useful pantry staples at the same time. Great for salads, marinades, and braises.

Cold Method (Maximum Flavor, Shorter Shelf Life)

1. Wash fresh herbs and dry them very well
2. Purée with a good olive oil or mild rapeseed oil, or briefly steep in oil
3. Fill into sterile bottles
4. Store in the fridge – keeps for 1–2 weeks

Warning: Cold herb oils can promote botulism if left at room temperature for too long. Always store cool and use up promptly!

Hot Method with Dried Herbs (Longer Shelf Life)

1. Dry the herbs completely first – only dried herbs keep water out of the oil
2. Heat the oil to 60–70 °C
3. Add the herbs (whole sprigs) and let them steep at that temperature for 10–15 minutes
4. Strain through a fine sieve – no plant material should be left in the oil
5. Fill into clean, dry bottles, seal

⚠️ Important: 60–70 °C sterilizes nothing. The spores of Clostridium botulinum survive anything below 121 °C. What makes this oil keep is not the heat but the fact that no moist plant material stays in it. For fresh herbs or garlic in oil, the same rule applies as for the cold method: fridge, and use it up promptly. Details: "Safe Canning: Avoiding Botulism"

Shelf life: 3–6 months stored cool and dark – provided you used dried herbs and strained the oil properly

Method 4: Herb Vinegar

Herb vinegar enhances salad dressings and marinades. White wine vinegar or apple cider vinegar work best.

Process:

1. Wash fresh herbs, pat dry
2. Put into a clean bottle
3. Heat the vinegar (don't boil, about 70 °C) and pour over the herbs
4. Seal, let steep 2–4 weeks
5. Strain out the herbs, transfer the vinegar into a sterile bottle

Shelf life: 12+ months

Method 5: Herb Salt

Herb salt is an all-purpose seasoning – and the simplest preservation method of all.

Process:

1. Very finely chop fresh herbs, or grind together with salt in a mortar
2. Use roughly 1 part herbs to 3–4 parts coarse sea salt
3. Mix well
4. Spread in an open dish and let dry (1–3 days)
5. Fill into jars

Tip combos:

• Wild garlic salt: wild garlic + sea salt → spring-like, intense
• Herbes de Provence salt: thyme + rosemary + oregano + lavender
• Parsley salt + lemon zest: great with fish and light meats

Infusing Herbs: Syrup and Liqueurs

Another way to preserve herbs: sugar or alcohol.

Elderflower syrup – the best-known example, but lemon balm, mint, or lavender can also be turned into syrups.

Herb liqueur: steep herbs in high-proof alcohol (grain spirit, vodka) for 2–4 weeks, then strain and sweeten with sugar syrup to taste.

Conclusion

Preserving herbs takes only a few ingredients and minutes – and pays off all winter long. If you build up a stock in summer, you'll still have the taste of fresh herbs in your kitchen come December. Whether dried, frozen, or turned into oil: each method has its own strengths and ideal uses.