How do I calculate the carbon footprint of rusk per kg?
Rusk is bread baked twice: add flour, sugar and fat with supplier figures, then the oven fuel for both bakes, slicing and packing. Divide the bakery's energy by kg of rusk packed, which is less than the dough weight after drying.
Ingredients
- Wheat flour, sugar, fat and milk solids by weight.
- Yeast and improvers.
- Packing film and cartons.
Baking
- First bake of the loaf.
- Slicing and second bake to dry the slices.
- Cooling and packing lines.
Per kg
Report per kg packed. Two bakes usually make rusk more energy intensive per kg than bread from the same oven.
Worked example: rusk unit per kg (one month)
- Electricity: 15,000 kWh x 0.710 = 10,650 kg CO2
- LPG: 6,000 kg x 2.98 = 17,880 kg CO2
- Rusk packed (kg): 120,000
- Plant total: 28,530 / 120,000 = 0.238 kg CO2 per kg
- Add flour, sugar, fat and packing for the full figure
Inputs are illustrative; use your own bills and production records.
What Senseible does here
Senseible reads the plant's electricity bills (CEA grid factor 0.710 kg CO2 per kWh, CO2 Baseline Database version 21.0) and fuel invoices (IPCC 2006 defaults) into a fingerprinted Scope 1 and 2 record, the plant-level input to a per-unit figure. Bought-in materials go to the supplier evidence trail; product reports are self-declared drafts.
Sources: GHG Protocol Product Standard, ISO 14067:2018, Carbon footprint of products (iso.org), IPCC 2006 Guidelines, Volume 2 Energy (fuel defaults), CEA CO2 Baseline Database, version 21.0
Last reviewed 2026-10-20.