As per the title, Holland and Barrett currently have 20% off Potter's Malt extract 650g, making it £3.87.
https://www.hollandandbarrett.com/shop/product/potters-malt-extract-60009811?skuid=009811
Not as good as their penny sale, but possibly useful information if you needed a top-up for your supplies :)
https://www.hollandandbarrett.com/shop/product/potters-malt-extract-60009811?skuid=009811
Not as good as their penny sale, but possibly useful information if you needed a top-up for your supplies :)