###### Abstract  
Wasted bread (WB) has been studied as an alternative ingredient for increasing the sustainable footprint in the beer production chain. There are gaps in the literature on the impact of WB on beer manufacturing. Thus, the objective was to evaluate the addition of WB as a replacement for wheat flakes in a craft beer. Three formulations with different concentrations of WB were produced and monitored for glucose and maltose concentrations in the mash; the beer was analyzed for ethanol, glycerol, acetic acid, lactic acid, pH, acidity, turbidity, color, and volatile compounds. Sensory analysis was performed by a trained panel. In the initial stages of mashing, a higher concentration of sugars was found in the word with WB added, while, at the end stages, this was higher in the control word. The addition of WB resulted in beers with a lower turbidity, darker color, and lower concentrations of ethanol, glycerol, and acetic acid. Among the volatile compounds, D-limonene, ethyl dodecanoate, heptanol, acetaldehyde, and ethyl acetate should be further explored as markers for the presence of WB. Higher intensities of banana odor and flavors were observed by the trained panel when there was a greater substitution of wheat flakes. WB is a low-cost and effective ingredient for beer production, although more work is needed for its large-scale use. a 2025133666133661336  
amount of wasted bread (WB); annual global bread production exceeds 100 million tons, and the estimated waste for bakery foods is around 10 million tons worldwide [4; 5]. Bread loss does not simply reflect the loss of the product itself but also the loss of various natural resources, such as the water, land, and energy used for the production of raw materials, transportation, and manufacturing [5]. Upcycled foods are defined as products consisting of or containing materials that otherwise would be wasted; these materials are turned into food products for human consumption, and this is carried out via a process that involves an increase in value [6]. The utilization of bread that has gone stale has been cited as a potential ingredient in producing upcycled foods [6]. In this scenario, the implementation of circular economy concepts along the food chain is an essential step in order to avoid wasting food ingredients that present valuable properties for food applications, thus achieving the Sustainable Development Goals [6]. Wasted bread is an important source of carbohydrates (expressed as starch) and proteins that can be employed in the fermentation process to avoid the waste of energetic compounds. It has been proposed for use as a substrate for enzyme production, yeast biomass, organic acids, and beer, among others [7; 8]. Beer is one of the most popular beverages worldwide, where carbohydrates from malled barley and/or non-malled adjuncts (corn, oat, and wheat) are used as carbon sources for yeast fermentation to generate alcohol and compounds of flavor and texture [7]. In this context, starch from bread is a source of easily fermentable sugars that results from the action of \(\alpha\)- and \(\beta\)-amylases in malt during beer mashing [9; 10]. Therefore, it is interesting to concentrate on waste streams with a high sugar content, where the extraction of fermentable sugars is convenient and low-cost, such as food, bakery, bread, fruit, and beverage waste, and these have received significant attention in recent years [11]. Wheat beer can contain a maximum content of 80% by weight of all beer adjuncts in relation to its original extract and a minimum of 20% by weight of barley malt [12]. Therefore, WB fits as an adjunct, and, in the formulations tested, it did not reach the maximum content permitted by law. In Brazil, craft beer follows ordinary legal standards for ingredients and processing facilities [12], and craft breweries differ from large companies mainly in terms of the volume of beverage produced. The relatively high selling price of craft beers has become an obstacle to market expansion and increased consumption [13].