A widely published authority on the archaeology of salt, Anthony Harding is author of the comprehensive Salt in Prehistoric Europe, published in 2013 by Sidestone Press. Rather than a simple summary of that book, the short volume reviewed here reflects Harding's efforts to include recent literature and to expand coverage to the early medieval period. He begins by reminding us that salt intake is critical for humans and other animals to regulate fluid balance. Humans also use salt for food preservation, as well as for medicinal, spiritual, and other purposes. Harding points out that there is much variation in production techniques depending on the source of the salt, available resources, demand, and cultural preference. His explanations of mining, quarrying, and evaporation techniques are informed by the most recent archaeological evidence and excerpts from historical documents when available.

The next four book sections are a chronological consideration of European salt production. The earliest evidence may date to the Mesolithic period but becomes more common during the Neolithic, which is not surprising given the association of grain-producing societies with dietary needs for salt supplements. Direct evidence for salt production includes abundant ceramics, called briquetage, and other tools at salt springs or rock salt outcrops. Harding provides examples from Romania, Bulgaria, and Poland and reviews compelling cases for Neolithic salt making from western Europe. He points out that multiple methods of production may already have been in use at this time.

Bronze Age salt production is marked by a standardization of techniques. Harding reviews in some detail the famous Hallstatt mine in Austria, which dates in part to the Middle and Late Bronze Age (around 1500–500 BC). Readers unfamiliar with this site and its remarkably preserved infrastructure and artifacts may be inspired to learn more. Hallstatt, however, is an exception to the widespread Bronze Age techniques of evaporation using either fire or the sun. Harding provides examples of sites from across Europe that produced briquetage and features indicative of making salt. He also reviews unusual cases from Romania and Ukraine, where freshwater was put in large wooden troughs from which it dripped through drilled holes onto rock salt, thereby facilitating the process of breaking it into manageable pieces for transport or trade.

The large amount of archaeological data from Iron Age and Roman salt production sites are reviewed next. Harding first returns to Hallstatt to describe the abundant Iron Age artifacts found there and at Hallein, another site in Austria that is remarkable for the large amounts of organic remains preserved in its mines. Most of this section is dedicated to summarizing the hundreds of brine-boiling sites found primarily near western European salt springs and coastlines. Subsections focus on France, with special emphasis on the Seille Valley and the Atlantic coast, where production reached industrial scale; Spain; Germany; northern Europe; and Britain. In many cases, Harding notes, the absence of technological changes makes it difficult to distinguish Iron Age from early Roman strata and sites. Despite variations across regions, the basic brine-boiling technology involved collecting brine from springs or the sea, concentrating it, and then applying heat until crystals formed. In most cases, briquetage can be found in such forms as clay containers, pedestals, spacers, and fire bars. There is also a range of features such as pits and furnaces that are related to heating the brine with fire. For readers unconvinced of the lengths to which humans have gone to obtain salt, the evidence presented in this section may quiet their doubts.

Greco-Roman salt production is covered in the next section. Harding first reviews the documentary records, which vary in their focus and level of detail; they cover production techniques, amounts, uses, prices, and other economic concerns. He includes individual subsections for Greece, Italy, and other salinae in the Roman world. Harding then mines the most recent literature to gather archaeological evidence for the distribution and production of salt during Roman times, concluding with a reminder that salt was a significant part of the Roman economy.

The most theoretically minded section of the book examines salt's economic and social contexts. Working back through time, Harding discusses the potential scales of production for specific sites from Romans to the Bronze Age. He concludes that, at least for Europe, there is no clear correlation between salt and social status. Finally, Harding walks the reader through the sequence of tasks for salt production and the known and potential solutions humans devised for each.

In only 73 pages of text, enriched by abundant recent archaeological evidence and relevant figures, Harding admirably condenses a large amount of information from the European continent to highlight salt's special role in human history.