# Sour Protein Bars
BUILT Sour Puff is Sweet & Tart on the Outside and Marshmallowy Inside

By Laura McQuarrie | Published 2026-02-13 | Lifestyle
Source: Trend Hunter, https://www.trendhunter.com/trends/built-sour-puff
References: [thedieline](https://thedieline.com/purse-candy-powerhouse-fun-dynamic-redesign-from-built-puffs-up-performance/) & [built](https://built.com/collections/shop-all/products/sp-variety)

![Sour Protein Bars](https://cdn.trendhunterstatic.com/thumbs/600/built-sour-puff.jpeg)

Protein bars are becoming more like candy bars as consumers demand products that deliver decadent flavors, satisfying textures and nutrition in a convenient bite, and BUILT Sour Puff sets itself apart on two counts—it has an irresistibly soft center and a sweet-tart coating. Flavor is important, and BUILT Sour Puff delivers deliciously different varieties like Blue Razz Blast Charge, juicy Sweet Peach Punch, and crisp Green Apple Crush.

Light, protein-rich BUILT PUFF with a marshmallowy middle now sports a fresh new look that focuses on flavor and candy bar-like indulgence. “We have consumers who have referred to our product as ‘purse candy,’ and so we had to have a package design that lived up to that promise,” said Megan Crossland, chief commercial officer at BUILT.