Petra 9 — Stone-Milled Wholemeal Flour, 12.5 kg Bag
Petra 9 is the wholemeal soft wheat flour of the Petra range: a complete flour that keeps the different parts of the grain, wheat germ included, milled on stone with the Augmented Stone Milling process. Protein runs 14.00 to 15.00 per cent, wet gluten 45 to 47 per cent, fibre 8.1 per cent and liquid absorption is above 90 per cent, one of the highest in the range. It is used on its own or cut at 10 to 30 per cent with a white flour to add fibre, colour and aroma without weighing down the structure. Supplied in a 12.5 kg paper bag, delivered by LAPA across Switzerland.
Technical Profile
Classification: wholemeal soft wheat flour. Protein 14.00 to 15.00 per cent. Mineral salts, meaning ash, 1.30 to 1.70. Fibre 8.1 per cent. Wet gluten 45 to 47 per cent. Moisture at most 15.5 per cent. Liquid absorption above 90 per cent. Nutritional values per 100 g: energy 1460 kJ or 345 kcal, fat 2.1 g, carbohydrates 63.1 g, fibre 8.1 g, protein 14.4 g. No additives. Allergen: gluten from soft wheat. One honest note on the data sheet: the mill does not publish W or P/L for this flour, because the fibre content makes the Chopin alveograph unreliable on a wholemeal. Any supplier quoting a W value for a wholemeal flour is quoting something the instrument cannot properly measure.
Augmented Stone Milling
The Petra process combines stone grinding wheels with cast-iron rollers, preceded by optical grain selection and followed by controlled sieving and calibration. Stone preserves the germ and the aromatic fraction that industrial roller milling strips out; the rollers and the calibration stage give the particle-size consistency that a professional dough needs to behave the same way every day. That combination is the point of the product: the flavour of a stone-milled wholemeal with the predictability of a modern mill.
Professional Uses
Five applications cover the range. First, wholemeal bread in every size, from small rolls to large loaves, at 60 to 90 per cent hydration with a slow, gentle bake. Second, wholemeal pizza, round or in a tray, where the flour brings colour and a nutty aroma. Third, blending: 10 to 30 per cent Petra 9 in a white-flour dough is the simplest way to put a wholemeal option on the menu without redesigning the process. Fourth, sweet leavened doughs and butter-rich doughs. Fifth, pastry work, shortcrust and sponge, plus fresh pasta, where the wholemeal note pairs particularly well with game and mushroom sauces.
Hydration and Fermentation
Recommended hydration is 60 to 90 per cent, high because the bran fraction absorbs a great deal of water. Fermentation runs at ambient 20 degrees Celsius for up to 16 hours, or refrigerated at 4 degrees Celsius for up to 48 hours. The producer recommends a slow, gentle bake so the crumb dries evenly and the crust develops a deep golden colour rather than burning at the surface while the centre stays wet.
Yield per 12.5 kg Bag
At 70 per cent hydration, a 12.5 kg bag plus 8.75 litres of water gives roughly 21.3 kg of dough. In a blend at 20 per cent, one bag covers around 62 kg of flour in total, which for most bakeries is several days of wholemeal production. Yeast and salt percentages remain those of your own recipe.
Storage
Wholemeal flour is more sensitive than white flour, because the germ carries fat that can go rancid. Keep the bags in a cool, dry, ventilated room at 20 to 22 degrees Celsius, raised off the floor on a pallet, away from the walls, in a clean area. Once open, use the bag within ten days to keep the aroma intact. Do not store next to strongly scented products: bran picks up odours.
Common Mistakes to Avoid
Three errors are worth avoiding. Looking for or quoting a W value for this flour is a technical mistake, as the mill itself explains. Hydrating it like a white flour, below 60 per cent, gives a dry, closed crumb and wastes the absorption capacity. Rushing the bake at high temperature colours the crust before the centre has dried, which is exactly the defect that makes customers say wholemeal bread is heavy.
Distribution and Logistics in Switzerland
LAPA stocks the Petra flours at its Embrach warehouse in the canton of Zurich and delivers with its own fleet to Zurich, Winterthur, Basel, Bern, Lucerne, St. Gallen, Zug, Aarau, Schaffhausen, Chur and Lugano. Areas outside the direct rounds are covered through Swiss Post, Planzer, Galliker and Camion Transport. Customers are bakeries, pizzerias, restaurants, hotels and catering companies, with volume pricing and scheduled replenishment.
Who It Is For
Petra 9 is for bakeries putting a real wholemeal loaf on the shelf, for pizzerias offering a wholemeal base, and for restaurants making their own bread. Sites that only want a hint of colour will use it in a blend; those working exclusively on white pizza doughs with long fermentation should look at Petra 5037 instead.
