Dried porcini is Boletus edulis and, depending on what the contract allows, the closely related species of the same group, collected from the wild, cleaned, sliced and graded after drying. It is not cultivated anywhere at commercial scale, which is the fact that shapes everything else about the category: supply follows weather rather than a production plan, volumes move by a factor of two or three between seasons, and the grade mix inside a season is decided by what the forest produced, not by what the buyer ordered.
Ukraine is a long-standing origin with an organised collection network and drying capacity in the forest regions. The commercial consequence of a wild origin is paperwork: a radioactivity certificate is required for entry into the EU, and the novel food question has to be answered for anything that is not a whole or sliced fruiting body. Both are covered in the specification table below.
Grades, cuts and calibration
Porcini grading is a visual system, and the letters are trade conventions rather than a standard. What follows is how the letters are normally used; write the description into the contract, not just the letter.
Grade A. Slices with pale cream to light tan flesh, tube layer light and intact, no dark discolouration, cap and stem attached in the slice so the characteristic outline is visible. Whole-slice share high, fines low. This is the grade sold to retail packers and to restaurant supply, where the product is looked at before it is eaten.
Grade B. Darker flesh, more olive or brown tube layer, more broken slices, some slices with the cap and stem separated. Aroma is normally unaffected. This is the working grade for sauces, risotto bases and soups, where the slice will be rehydrated and cut down anyway.
Grade C and pieces. Fragments, dark slices, high fines share. Bought for powder, for stock and for extract work where appearance is irrelevant and only aroma and dry matter are being paid for.
Slice thickness. Nominal 2 to 4 mm is the mainstream. Thinner slices dry faster and rehydrate faster but break more in transit; thicker slices survive handling and hold texture after rehydration but need a longer, gentler dry. Thickness and the tolerance around it should both be specified, because a nominal figure with no tolerance is not enforceable.
Defects that actually get lots rejected. Insect channels in the stem, sand and grit trapped in the tube layer, and foreign mushroom species that entered at collection. All three are defect categories that have to carry a numeric maximum, not the word ‘minimal’.
Seasonality and availability
Collection runs from July to October, with the productive period concentrated in the weeks after late summer rain. A dry August can halve a season; a wet one can produce more than the drying capacity can absorb, which is why the worst quality in a good year is often the material that waited too long for a dryer.
Because the crop is annual and cannot be scheduled, supply is a stock question rather than a production question. Material shipped in March comes from the previous autumn’s collection, held in conditioned store. That is normal and does not indicate a problem, but it does mean the buyer should ask for the collection season on the specification and should read the moisture and water activity figures on a certificate dated close to shipment rather than one dated at packing.
Pricing behaves accordingly. The grade A share of a season is the scarce element, and in a poor year the spread between grade A and grade B widens far more than the average price moves. A buyer who can work with grade B, or who can take a defined A and B blend, has a materially more stable cost line than one who is locked to grade A.
What the buyer checks at intake
- Moisture and water activity on the arriving lot, not the packing certificate. Dried mushrooms are hygroscopic and a lot that left the packer compliant can arrive above specification if the liner was breached or the container sweated.
- Grade verification against a retained reference sample, on a weighed sub-sample rather than by eye. Grade drift between the offered sample and the delivered lot is the most common commercial dispute in this category.
- Broken slices and fines as a weighed percentage after sieving, because fines are worth a fraction of whole slices and a high fines share is a silent price change.
- Sand and grit, assessed by washing a sub-sample and weighing the residue. The tube layer traps grit and it does not come out in rehydration.
- Insect activity, both live and evidence of past damage. A warm store during transit can restart activity that was dormant at packing.
- The radioactivity certificate and the analytical report attached to the consignment, checked for lot identity against the marking on the cartons.
Where it is used
Food service is the largest destination. Slices are rehydrated and used in risotto, pasta sauces, meat braises and soups, and the rehydration water is normally used as stock, which is why grit and off-aromas matter more here than the appearance grade suggests.
Retail private label takes grade A in small units, usually 20 to 50 g, where the product is visible through a window and the appearance grade is the whole proposition. This is the most demanding channel on slice integrity and colour, and the least demanding on volume.
Industrial users buy grade B, C and pieces for dry soup mixes, sauce bases, seasoning blends and mushroom powder. Here the purchase is aroma and dry matter per kilogram, and the specification should say so: a volatile aroma assessment against a reference, a moisture maximum and a defined particle size after milling are more useful than a grade letter.
Extract and concentrate work is a separate conversation, because a concentrated fraction is not automatically covered by the traditional-consumption argument that keeps the whole fruiting body outside the novel food regime.
Standards and routes
Dried porcini is a low density, high value cargo. A pallet of cartons weighs little and fills a lot of space, so groupage and part loads are normal and full truck loads are unusual outside the peak dispatch months. Road groupage through the Poland corridor and onward to German consignees is the standard route.
Two documents govern acceptance at the border. The first is the official certificate required by Commission Implementing Regulation (EU) 2020/1158 for products from listed third countries, which covers caesium contamination and applies specifically to wild mushrooms; Commission Implementing Regulation (EU) 2024/256 extended the scope to processed products and mixtures containing wild mushrooms, with the level calculated on the reconstituted product. The second is the phytosanitary certificate where the plant health regime requires one for the commodity code and origin.
Certification on the supply side is normally BRCGS or IFS Food at the drying and packing site. Neither covers the collection network, which is why a documented collector registration and traceability scheme back to the collection area is a separate question that has to be asked directly.
