Here is the full list of ingredients in Riddle-Me-Rye white sourdough:
100% organic wheat flour, water, salt.
Here is the list of ingredients in a well known British supermarket own-brand white loaf:
Wheat Flour, Water, Yeast, Salt, Rapeseed Oil, Spirit Vinegar, Emulsifiers (Mono- and Di-Acetyl Tartaric Acid Esters of Mono- and Di-Glycerides of Fatty Acids, Sodium Stearoyl-2-Lactylate, Mono- and Di-Glycerides of Fatty Acids), Soya Flour, Preservative (Calcium Propionate), Palm Oil, Flour Treatment Agent (Ascorbic Acid).
Need I say more?!