As a control system engineer, I can confirm you're correct that store brand items are often made in the same factory, using the same equipment as brand items.
However in every factory I've worked in, there have always been differences in quality.
Active or expensive ingredients are reduced or replaced. Soaps concentration is lowered, butter and cocoa is reduced/replaced, less pulses(beans) or fruit in the tin, drained weights are lowered, quality control is not as strict, etc.
Regarding quality control - often factories would clean the line prior to running the high end product. Switching over to the cheaper product usually consists of switching the packaging out and topping up the supply with the cheaper product - no clean or flushing of the line. The first couple of items produced would be different quality to the rest of the batch.
You have to cut some corners to compete with big companies like p&g and Unilever. They're buying and producing much larger quantities of products than any generic brand.
Regarding cheap packaging - you pay per colour when printing. Printing materials can also be swapped out. Thinner plastic or card. Matt instead of high gloss.
However in every factory I've worked in, there have always been differences in quality.
Active or expensive ingredients are reduced or replaced. Soaps concentration is lowered, butter and cocoa is reduced/replaced, less pulses(beans) or fruit in the tin, drained weights are lowered, quality control is not as strict, etc.
Regarding quality control - often factories would clean the line prior to running the high end product. Switching over to the cheaper product usually consists of switching the packaging out and topping up the supply with the cheaper product - no clean or flushing of the line. The first couple of items produced would be different quality to the rest of the batch.
You have to cut some corners to compete with big companies like p&g and Unilever. They're buying and producing much larger quantities of products than any generic brand.
Regarding cheap packaging - you pay per colour when printing. Printing materials can also be swapped out. Thinner plastic or card. Matt instead of high gloss.