In archaeological contexts, identifying processes of beer production and consumption has contributed to our understanding of agriculture, labor mobilization, economic surplus, feasting, gender dynamics, social structure, tribute, community, identity and politics. Nevertheless, in the absence of pictorial representations and characteristic objects, beer brewing is difficult to identify in the archaeological record, and molecular methods are often limited by constraints of preservation and specificity. A potential target for studies of ancient beer production are residues formed during brewing activity, including beerstone, a calcium oxalate residue. Here, we apply shotgun proteomics analyses to a sample of modern beerstone to explore this residue's capacity as a marker for beer in archaeological contexts. The beerstone proteome was compared to the protein profiles of ungerminated and germinated barley to identify key proteins indicative of malted grains which may be encased by the residue. Proteins matching to barley grain () and Baker's/Brewer's yeast () were successfully identified in the beerstone. In particular, we identified hordeins, lipid transfer proteins, trypsin/α-amylase inhibitors, and protein Z, which are barley proteins abundant in proteomic characterisations of beer. In comparison to ungerminated and germinated barley grains, we find that beerstone preserves only a subset of the barley proteome, with the residue being more reflective of the final brewing product than of earlier brewing steps such as malting. Overall, we demonstrate that beerstone has potential to entrap and preserve proteins reflective of the beer-making process and identify proteins that we might anticipate in future archaeological analyses.

中文翻译：

---

千方百计：探索啤酒石的宏蛋白质组以鉴定考古啤酒生产


在考古背景下，识别啤酒生产和消费的过程有助于我们理解农业、劳动力动员、经济剩余、宴会、性别动态、社会结构、贡品、社区、身份和政治。然而，由于缺乏图示和特征物体，啤酒酿造很难在考古记录中识别，而分子方法往往受到保存和特异性的限制。研究古代啤酒生产的一个潜在目标是酿造过程中形成的残留物，包括啤酒石（一种草酸钙残留物）。在这里，我们对现代啤酒石样本进行了鸟枪法蛋白质组学分析，以探索这种残留物在考古环境中作为啤酒标记的能力。将啤酒石蛋白质组与未发芽和发芽大麦的蛋白质谱进行比较，以确定可能被残留物包裹的指示麦芽谷物的关键蛋白质。在啤酒石中成功鉴定出与大麦粒 () 和面包/啤酒酵母 () 匹配的蛋白质。特别是，我们鉴定了大麦醇溶蛋白、脂质转移蛋白、胰蛋白酶/α-淀粉酶抑制剂和 Z 蛋白，它们是啤酒蛋白质组特征中丰富的大麦蛋白。与未发芽和发芽的大麦谷物相比，我们发现啤酒石仅保留了大麦蛋白质组的一个子集，与早期的酿造步骤（例如麦芽制造）相比，残留物更能反映最终的酿造产品。总的来说，我们证明啤酒石有潜力捕获和保存反映啤酒酿造过程的蛋白质，并识别我们在未来考古分析中可能预期的蛋白质。