Combine this with the £18 pound off a £60 spend. You do need £20 worth of none alcohol though.

Mini bottles included in the offer too!
http://www.sainsburys.co.uk/shop/gb/groceries/drinks/CategoryDisplay?langId=44&storeId=10151&catalogId=10122&categoryId=209298&pageSize=30&beginIndex=0&promotionId=&listId=&searchTerm=&hasPreviousOrder=&previousOrderId=&categoryFacetId1=&categoryFacetId2=&bundleId=&parent_category_rn=12192&top_category=12192&orderBy=PRICE_ASC#langId=44&storeId=10151&catalogId=10122&categoryId=209298&parent_category_rn=12192&top_category=12192&pageSize=30&orderBy=PRICE_ASC&searchTerm=&beginIndex=0

Should the discount show when checking out?

I think they must just overcharge the rest of the time as Sainsbury's are always doing this offer, same with their Tu clothing, every few weeks it's 25% off - I reckon people who buy at the full price are subsidising it.

Doesn't seem to work. Are there any conditions that need to be met for the discount?

Cheers op another new account opened and £20 off £100 code used

No point me doing it, everytime and I mean everytime they deliver only 5 saying that 6 weren't available. Funny that isn't it, just so I don't get 25% off.
Thanks for letting people know though OP, heat added