Supermarkets have been criticised for years for underpaying dairy farmers and have been selling home-brand items at below cost prices in order to draw in customers and profit on other lines of products. It's a well known story.
A rise that brings a home-brand product price closer to branded competitor products is not a sign of hyperinflation.
Also, I would suggest using the percentage price comparison against the branded competitor good, say 1L of "Brownes" milk would be better. (~$1.88/L) It would be a much smaller percentage and somewhere around 13% as an example.