The Challenge
Stone & Wood wanted to give customers something no standard Shopify feature could offer: build a mixed carton of beer, choosing from the range, with the price updating as beers are picked.
Off-the-shelf bundle apps were either too rigid, forcing fixed pack sizes and predetermined combinations, or too heavy, adding needless complexity to the checkout. The experience needed to feel native to the Stone & Wood brand: relaxed, playful and effortless. And it had to work for the team behind the scenes: warehouse orders had to be accurate, stock had to be honest, and staff had to be able to run it without calling a developer.
The Approach
I started by understanding the constraints. Shopify’s cart doesn’t natively support “build your own” products, and most apps bolt on extra logic that fights the store’s existing flow.
Instead, I built a custom app for Stone & Wood and worked with the way Shopify is built. The app uses Shopify Functions (small pieces of code that run inside Shopify’s cart and checkout), so the carton and its price are handled by Shopify itself, not by scripts layered on top.
Three decisions shaped it:
- A carton should feel like a carton. Customers pick beers and watch the slots fill. No forms, no extra steps, straight to checkout.
- Be fair, and be honest. Mixing earns a discount on the case price, never a way to pay less than the case. Customers can only pick beers that are actually in stock.
- Put staff in control. Everything that changes, from which beers are offered to the discount, is something the team can adjust themselves.
The Solution
A custom Shopify app, built for Stone & Wood, that powers the carton on the product page and gives staff the controls behind it:
- Visual carton: empty slots fill as customers choose their beers, and the add to cart button only switches on when the carton is full
- Price that follows the picks: customers see a “from” price, then the exact total, with the saving shown
- Pricing based on the case: a carton is priced from the case price less the mixing discount, so it always stacks up fairly
- Stock-aware choosing: sold-out beers can’t be picked, and a beer with only two left can only fill two slots
- A fair-play check: if a customer picks the same beer for every slot, they’re offered the real case at its normal price
- Contents shown in the cart: the carton’s beers are listed so customers know exactly what they’re buying, and the order reaches the warehouse as the individual beers
- Staff-managed in Shopify: set a carton’s fixed beers and “pick one of these” slots, choose the discount, see the price before saving, and get a nudge when beer prices have changed so the carton can be refreshed
- Phones and desktops: it works the same way on both
Around the carton, I also built a few smaller tools for the store:
- Free gift with purchase, added and removed automatically
- Staff discount for the team’s own orders
- A checkout add-on offer for relevant extras
- A free-shipping progress banner, so customers see how close they are
Because it is a purpose-built app, it fits Stone & Wood’s range and rules exactly, and stays fully in their control.
Working with breweries
Breweries are a regular part of my work, and Stone & Wood is one of them. I know how drinks businesses sell: customers who like to mix and match, packs and cartons that suit the range, and online shops that sit alongside other ways of selling. If you run a brewery or make drinks, you won’t need to explain your business to me from scratch.
The Result
The result is a Build Your Own Carton that feels like part of the Stone & Wood store rather than something bolted on: customers fill a carton visually, see the price update as they go, and head straight to checkout. Behind the scenes, the team can run it without a developer, stock stays honest, and the warehouse gets accurate orders.