Choose one or two jars below. Check milk/yogurt allergens and whether certified gluten-free oats are needed.
One jar = one serving. Totals scale the base; variations below are per jar.
Mix the base in clean covered jars; refrigerate overnight at 4°C or below. Stir before eating; add a splash of milk if too thick.
If too thick, add liquid a tablespoon at a time. If too loose, use less liquid in the next batch rather than assuming every oat brand absorbs identically. Nuts or seeds are optional additions only when suitable for the eater.
Make one or two jars at a time, label the date, keep chilled, and use within two days as a conservative preparation plan. Follow any shorter use-by guidance for ingredients. Keep perishables out of refrigeration for no more than two hours, or one hour above 32°C.