Preservation and Storage

Fresh Mushrooms: Storage Rules

Immediately After Foraging

• Transfer mushrooms to a basket (not a plastic bag!) — see Forager’s equipment
• Brush off soil and debris in the field, do not wash
• Discard wormy and damaged specimens immediately

In the Refrigerator

• Temperature: 2–4 °C
• Place mushrooms on a tray, cover with a paper towel (not cling film!)
• Do not wash before cooking — moisture accelerates spoilage
• Shelf life: no more than 24 hours (48 hours maximum for firm species like porcini)

Mushrooms That CANNOT Be Stored

• Inkcaps (Coprinus spp.) — autolyse (liquefy) within hours
• Old specimens of any species — deteriorate faster than fresh ones
• Mushrooms collected in rain — spoil 2–3 times faster

Drying (desidratação)

The oldest and most reliable preservation method. Especially good for species with intense aroma.

Best Species for Drying

• Porcini — the king of dried mushrooms, aroma intensifies dramatically
• Bronze bolete — similarly excellent
• Chanterelle — retains aroma but texture changes
• Horn of plenty — dries excellently
• Honey fungus — popular dried
• Morels (Morchella) — a dried mushroom classic

Drying Methods

Dehydrator (best option)

• Temperature: 50–55 °C
• Time: 2–6 hours (depends on slice thickness)
• Cut into 3 mm slices
• Spread evenly on trays

Oven

• Start at 45 °C, then increase to 60–65 °C
• Door ajar for air circulation
• Time: 1–2 hours, flip halfway through
• Check: mushrooms should be dry and crisp, not burnt

Sun-drying

• Slice mushrooms, spread on a rack
• Cover with cheesecloth (to keep flies away)
• Turn 2–3 times daily
• Time: 3–4 sunny days
• Suitable for Portugal’s climate (especially the south)

Storing Dried Mushrooms

• Glass jar with a tight lid
• In a dry, dark, cool place
• Shelf life: up to 1 year (up to 2 years in ideal conditions)
• Can be ground into mushroom powder — a universal seasoning

Rehydrating Dried Mushrooms

1. Soak in warm water (not boiling!)
2. Leave for 20–30 minutes
3. Remove mushrooms, squeeze gently
4. Save the soaking liquid — it’s concentrated mushroom stock, perfect for sauces and risotto

Freezing (congelação)

Preparation

• Clean and slice
• Blanch 2–3 minutes in boiling salted water (for most species)
• Cool in ice water
• Pat dry with paper towels
• Spread on a tray in a single layer, freeze
• Transfer to airtight bags

Without Blanching

Some species can be frozen raw:

• Porcini — slice and freeze directly
• Chanterelle — best to sauté first, then freeze

Storage Times

• Blanched: up to 6 months at –18 °C
• Sautéed: up to 3 months
• Thawing: do not fully thaw — cook from frozen

Mushrooms in Oil (cogumelos em azeite)

Safe Method

The only scientifically proven way to make mushrooms in oil safe is to lower the pH below 4.6 before adding oil:

1. Boil mushrooms in a vinegar solution (1:1 ratio water to 6% vinegar) — 15–20 minutes
2. Allow to cool completely
3. Pack into sterilised jars
4. Cover completely with olive oil
5. Store in the refrigerator (not at room temperature!)
6. Shelf life: no more than 2 weeks

What NOT to Do

• Pour oil over mushrooms without prior vinegar treatment
• Store at room temperature
• Use non-airtight containers
• Keep for more than 2 weeks (home preservation)

Pickling (conserva em vinagre)

A safer method than oil preservation:

1. Boil mushrooms 15 minutes in salted water
2. Drain
3. Prepare brine: water, vinegar (6%), salt, black peppercorns, bay leaf
4. Bring brine to a boil
5. Pour hot brine over mushrooms
6. Seal sterilised jars
7. Store in a cool, dark place

The brine pH must be below 4.6 — this is critical for safety.

Salting (salga)

A traditional but less common method in Portugal:

• Alternate layers of mushrooms and coarse salt
• After 2–3 days, mushrooms will settle — add more
• Store in the refrigerator
• Before use — soak in several changes of water (6–12 hours)

Mushroom Powder (pó de cogumelos)

A universal seasoning from dried mushrooms:

• Grind dried mushrooms in a coffee grinder or blender
• Store in an airtight jar
• Add to sauces, soups, risotto, meats
• Best of all: powder from dried porcini — intense umami

ASAE Recommendations

Portugal’s Food Safety Agency (ASAE) recommends:

• Do not store raw mushrooms for more than 24 hours
• Do not reheat mushroom dishes
• Keep a sample of each species consumed (in case of poisoning)
• Do not forage near roads, industrial facilities, or urban areas — mushrooms accumulate heavy metals
• More: Safety rules

Sources

1. ASAE — Consumo de Cogumelos Silvestres
2. DGADR — Manual de Boas Práticas de Colheita e Consumo de Cogumelos Silvestres
3. Agricultura e Mar — Boas práticas na apanha, conservação e consumo de cogumelos silvestres
4. CCRES — Boas práticas de recolha
5. Clicasim — Conserva de Cogumelos em Azeite: Guia de Segurança
6. Retratos da Serra — Como desidratar cogumelos em casa