Introduction
Context, research gap, and aim of the study
The introduction of ceramic technology to the Danube region occurred with the arrival of the first Neolithic communities (Jordan et al., Reference Jordan, Gibbs, Hommel, Piezonka, Silva and Steele2016; Thissen, Reference Thissen, Reingruber, Tsirtsoni and Nedelcheva2017), along a route originating in Anatolia, south-eastern Europe, approximately 8000 years ago (Mathieson et al., Reference Mathieson, Alpaslan-Roodenberg, Posth, Szécsényi-Nagy, Rohland and Mallick2018). The change in type and frequency of pottery tempers represents one of the most striking technological differences between the Early Neolithic and the Middle/Late Neolithic and Chalcolithic pottery traditions in the Middle and Lower Danube region. Pottery tempered with agricultural by-products, collectively termed chaff, is considered characteristic of early pottery assemblages, including those found in southern Romania. Recent studies have greatly advanced our understanding of this tradition, revealing its widespread distribution and persistence for nearly one millennium (Kreiter et al., Reference Kreiter, Pető, Pánczél and Bánffy2013; Spataro, Reference Spataro2019; Papadakou et al., Reference Papadakou, Kotsakis and Urem-Kotsou2021; Dzhanfezova, Reference Dzhanfezova2021). Grog, or crushed pottery, did not emerge as an intentionally used temper in the Early Neolithic of the Middle and Lower Danube Basin, nor in contemporary or adjacent cultures in the eastern Adriatic (Spataro, Reference Spataro2019). BC
During the second half of the sixth millennium bc, a buffer zone emerged between the Danube and the Carpathians in southern Romania (Figure 1), in which innovations spread through contact and exchange following multiple communication routes: south to north, west to east, and north to south (Reingruber, Reference Reingruber, Reingruber, Tsirtsoni and Nedelcheva2017). Based on scarce published information, it appears that grog-tempered pottery began to be used in the region around 5300/5000 bc (Ștefan, Reference Ștefan2023), and became frequent during the fifth millennium bc (Comşa, Reference Comşa1974; Opriș et al., Reference Opriș, Lazăr and Ignat2017; Koutouvaki et al., Reference Koutouvaki, Amicone, Kristew, Ștefan and Berthold2021; Stoicescu et al., Reference Stoicescu, Duliu, Opriş, Manea, Mariş and Voinea2023). Yet, little is known about the origin, dispersal, and intensity of this ceramic technology.

Figure 1. Distribution map of Middle Neolithic and Chalcolithic sites in southern Romania with data on pottery inclusions analysed. 1) Milcovu din Deal; 2) Mavrodin-Pod; 3) Nanov-Vistireasa; 4) Măgura-Bran; 5) Teleor 008; 6) Căscioarele-Ostrovel; 7) Radovanu-La Muscalu; 8) Gumelnița-Tell; 9) Gumelnița-Terrace; 10) Sultana-Ghețărie; 11) Sultana-Malu Roșu; 12) Berceni-Site 12; 13) Bragadiru-La Moară; 14) Chitila-Așezare; 15) Băneasa-Lac; 16) București-Șoseaua Nordului; 17) Crețuleasca; 18) Aldeni-Gurguiul Balaurului; 19) Bordușani-Popină; 20) Carcaliu (base map: https://maps-for-free.com).
Over the past century, numerous researchers have investigated grog-tempered pottery from various analytical angles. While some scholars have primarily acknowledged the presence of grog within ceramic fabrics, others have delved deeper into the complexities of this tempering technique. These comprehensive case studies have expanded our horizons, addressing issues ranging from definitions and research methodology to technological properties, cultural traditions, economic networks, social implications, recycling practices, and ethnographic models (Whitbread, Reference Whitbread1986; Kreiter, Reference Kreiter2007; Holmqvist et al., Reference Holmqvist, Larsson, Kriiska, Palonen, Pesonen and Mizohata2018; Holmqvist, Reference Holmqvist2021). For the Middle and Lower Danube region, the use of grog by Middle Neolithic, Late Neolithic and Chalcolithic communities has been recognized as a common practice (Merkyte et al., Reference Merkyte, Albek, Sørensen Østergard and Zidarov2005; Vuković, Reference Vuković2015, Reference Vuković, Spataro and Furholt2020; Spataro, Reference Spataro and Burnez-Lanotte2017; Amicone et al., Reference Amicone, Mathur, Pavitra, Mirković-Marić, Pantović and Kuzmanović-Cvetković2020). However, only sporadic data on this tradition have been collected for in-depth analyses (see Hofmann, Reference Hofmann, Spataro and Furholt2020 for the central and western Balkans). Grog has also been considered as a potential source of object fragmentation, albeit with caution, and viewed as exceptionally rare in some contexts (Chapman, Reference Chapman2000).
The aim of this article is to trace and explain the appearance and distribution of grog-tempered pottery in the late sixth and the fifth millennia bc in Romania’s Lower Danube area, following specific objectives. These are: (i) investigating to what extent grog-tempered pottery was employed by Neolithic and Chalcolithic communities; (ii) detecting its temporal and geographical spread; (iii) identifying and explaining variability. The information gathered from published sources is combined with new results obtained from the macroscopic and archaeometric analyses of pottery assemblages from Middle Neolithic and Early and Middle Chalcolithic sites or levels from southern Romania.
Inclusions in the Neolithic and Chalcolithic pottery from Romania’s Lower Danube region
During the twentieth century, Neolithic and Chalcolithic pottery fabrics from southern Romania were typically classified into three main types: fine, semi-fine/medium, and coarse. These categories, established by scholars such as Dumitru Berciu (Reference Berciu1961), Eugen Comșa (Reference Comşa1974), and Valentina Voinea (Reference Voinea2005), refer to the general characteristics of the inclusions in the paste, often without quantification of these inclusions. In many cases, the frequency of inclusions was assessed only approximately, leading to semi-quantitative data. These observations were then used to support theories of cultural evolution, suggesting transitions from one cultural phase to another.
Publications containing both qualitative and quantitative data on ceramic inclusions are relatively rare and have appeared primarily in the last two decades. Notable examples include works by van As et al. (Reference van As, Jacobs and Thissen2006), Burens et al. (Reference Burens, Ailincăi, Micu, Carozza and Lăzurcă2010), Opriș et al. (Reference Opriș, Bălăşescu and Lazăr2012, Reference Opriș, Lazăr and Ignat2017), Thissen (Reference Thissen2014), Opriș and Ștefan (Reference Opriș and Ștefan2016), Lazăr et al. (Reference Lazăr, Bălășescu, Crăciunescu, Covătaru, Danu and Darie2017, Reference Lazăr, Opriș, Ignat, Manea, Frujină and Covătaru2020), and Ștefan (Reference Ștefan2021, Reference Ștefan2023). These studies have been complemented by archaeometric analyses aimed at clarifying aspects related to clay sources, and to the type, shape, size, and quantity of non-plastic materials in pottery (van As et al., Reference van As, Jacobs and Thissen2006; Dimache & Haită, Reference Dimache and Haită2015; Ignat et al., Reference Ignat, Luca, Dimofte, Lazăr, Constantin and Bugoi2019; Koutouvaki et al., Reference Koutouvaki, Amicone, Kristew, Ștefan and Berthold2021; Stoicescu et al., Reference Stoicescu, Duliu, Opriş, Manea, Mariş and Voinea2023). While these studies have revealed traditions and changes in tempering practices at site level, there remains a lack of sufficient data to thoroughly investigate these technological features on a large time scale over a long time span and across a region that ranges from the Carpathians to the Danube.
Materials and Methods
Materials, contexts, and chronology
The analysis of qualitative, quantitative, and semi-quantitative data on pottery inclusions from existing publications, combined with unpublished data from ten sites (twelve levels), includes the microscopic investigation of three assemblages from the Gumelnița tell site and macroscopic information obtained from ten pottery assemblages. Overall, the data came from twenty sites (thirty-two levels) located between the river Olt in the west, the Carpathian Mountains in the north, the Măcin Mountains in the east, and the river Danube in the south (Figure 1). Microscopic examination was conducted on 310 samples from eleven sites or levels (Supplementary Material Table S1), while 30,836 sherds from twenty-three sites or levels were examined macroscopically (Supplementary Material Table S2). Both the published and unpublished assemblages came from domestic contexts, mostly pits and a small part from dwellings.
Absolute chronology is based on published (Thissen, Reference Thissen2014; Opriș et al., Reference Opriș, Lazăr and Ignat2017; Lazăr et al., Reference Lazăr, Opriș, Ignat, Manea, Frujină and Covătaru2020; Ștefan, Reference Ștefan2021; Popescu et al., Reference Popescu, Covătaru, Opriș, Bălășescu, Carozza and Radu2023) and unpublished calibrated radiocarbon dates, together covering fifteen sites or levels (Supplementary Materials Figure S2 and Table S3). For the remaining sites or levels, chronology was estimated (marked in grey in Supplementary Material Tables S1–S2) by comparing vessels, primarily their shape and decoration (Supplementary Material Figure S1), with pottery from securely radiocarbon-dated sites. Combining all the information from relative and absolute chronology, the current study covers three periods, three cultural traditions, and eight phases between 5400 and 3800 bc (Table 1).
Table 1. Periods, cultures, phases, and chronology of pottery traditions in southern Romania analysed in the current study (see Petrescu-Dîmbovița & Vulpe, Reference Petrescu-Dîmbovița and Vulpe2001 for local terminology; Supplementary Materials Figure S2 and Table S3 for dating).

Grog and its identification
Grog, a commonly used pottery tempering material (Rice, Reference Rice1987), is defined as ‘any fired-clay product that is crushed and utilized as an aplastic in the pottery’s clay’ (Porter, Reference Porter1964: 521), known worldwide in various contexts, from Neolithic to modern times (Holmqvist, Reference Holmqvist2021). It can be identified by the naked eye due to its specific consistency and the angular shape of its grains. Additional factors that aid in its identification include the variety of colours, dimensions of the grains, and distribution within the clay matrix (Figure 2). Usually, these characteristics make it possible to identify grog-tempered pottery, even without microscopic analysis. There are, however, instances where grog can be mistaken for natural non-plastic materials such as argillaceous rock fragments or iron oxides (Szakmány et al., Reference Szakmány, Vanicsek, Bendő, Kreiter, Pető, Lisztes-Szabó, Horváth, Amicone, Quinn, Marić, Mirković-Marić and Radivojević2019). Petrological and microscopic analyses (Whitbread, Reference Whitbread1986) can help reduce or eliminate this risk. Elisabeth Holmqvist (Reference Holmqvist2021) provides a comprehensive overview of grog added to archaeological ceramics, highlighting key characteristics such as angular or irregular grain shapes, narrow shrink-rim/void, close bonding with the host matrix, contrasting microstructure alignment with the host fabric, different microstructure from the host fabric, irregular grain size compared to argillaceous rock inclusions (e.g. mudstone), and frequent occurrence and even distribution in the host fabric (Figure 3).

Figure 2. Rim sherd of grog-tempered pottery from Berceni-Site 12, Boian-Giulești phase.

Figure 3. Ceramoclasts (grog) in thin section of a pottery sample from the Gumelnița tell, Gumelnița A2 phase.
Results
Microscopic analysis of tempered pottery
The microscopic characterization of pottery constituents observed in thin sections is a classic archaeometric method of ceramic analysis. It helps identify the quality and quantity of inclusions in the clay matrix, as well as their shape, size, distribution, and transformation during firing (Quinn, Reference Quinn2013). There are few published petrological data on pottery samples from the Middle Neolithic and Chalcolithic periods in southern Romania. Moreover, the existing studies have employed various adapted protocols for analysis, leading to a heterogeneous set of records (e.g. van As et al., Reference van As, Jacobs and Thissen2006; Dimache & Haită, Reference Dimache and Haită2015; Ignat et al., Reference Ignat, Luca, Dimofte, Lazăr, Constantin and Bugoi2019; Koutouvaki et al., Reference Koutouvaki, Amicone, Kristew, Ștefan and Berthold2021). Tempers and natural non-plastic materials were not always distinguished, and the results were expressed in various ways, including numbers, percentages, or written descriptions. To normalize and gather all these results in a coherent way for this study, clearly intentionally added inclusions (i.e. dense chaff and grog) were counted separately, while the rest were counted together (i.e. no temper and other types of inclusions), and expressed as percentages. As noted earlier, data were collected from eleven sites or levels and comprise information on 310 pottery fragments (Supplementary Material Table S1).
The microscopic examination of the thin sections revealed the presence of grog in nearly all the sites or levels analysed, with occurrences ranging from 87.5 to 100 per cent. Notably, the absence of grog and the intensive use of organic tempers was documented at the Middle Neolithic site of Milcovu din Deal and the Chalcolithic sites of Teleor 003 and Măgura-Bran. The latter two sites are located close to one another in the western part of Wallachia.
Macroscopic examination of tempered pottery
The macroscopic data on pottery inclusions extracted from the literature was obtained by various authors using different recording criteria. Only the results expressed both qualitatively and quantitatively were selected for the present analysis and combined with supplementary data obtained from the investigation of unpublished pottery assemblages from nine sites or levels. To facilitate comparison with the results from microscopic analyses, chaff, grog, and their mixtures were recorded separately, while pottery with no temper or with natural inclusions (i.e. sand, pebbles, calcareous concretions) were grouped together.
Overall, data on pottery inclusions from twenty-three sites or levels were collected, comprising over 30,000 sherds (Supplementary Material Table S2). Grog-tempered pottery, either alone or combined with chaff, was identified in varying proportions across seventeen sites or levels. Its presence was minimal or entirely absent at Middle Neolithic sites. Conversely, it was predominant in Early and Middle Chalcolithic contexts, with exceptions noted at the Boian-Spanțov sites in western Wallachia and the Gumelnița A2 site at Carcaliu in north-western Dobrogea.
Despite the prevalence of grog tempering in many areas during the fifth millennium bc, there are distinct regional variations in pottery tempering from western Wallachia to north-western Dobrogea. In western Wallachia, chaff was the predominant tempering agent (Thissen, Reference Thissen2014; Opriș & Ștefan, Reference Opriș and Ștefan2016). In contrast, at the Carcaliu site, mineral tempers such as sand and calcareous concretions were more common, grog being a relatively sparse (Burens et al., Reference Burens, Ailincăi, Micu, Carozza and Lăzurcă2010). For the remainder of the macroscopically analysed Chalcolithic sites or levels, grog-tempered pottery was predominant, with shares ranging from 51.3 per cent at Căscioarele-Ostrovel to 95 per cent at the Gumelnița tell.
Kernel density estimation
In addition to the descriptions of shape and decoration used to infer the relative chronology of the finds, brief remarks about the quality of the inclusions observed in the pottery paste were often included in local archaeological studies. Consequently, qualitative and quantitative descriptions of the composition of the ceramic fabrics were often short and subjective, reflecting the individual experience and objectives of the archaeologists. Anthropogenic inclusions, such as grog or chaff, were usually mentioned, whereas natural inclusions like sand, gravel, or calcareous concretions were more rarely specified.
To collect and organize the disparate information gained from publications more systematically, the qualitative statements were converted into quasi-quantitative assessments. This was achieved by approximating the frequency of primary non-plastic inclusions with numerical values ranging from 0 to 4, where 4 denotes predominant, 3 frequent, 2 rare, 1 very rare, and 0 absent or no data.
By synthesizing all the available data, including sites where both qualitative and quantitative data were available (Supplementary Materials Tables S1–S2), a comprehensive dataset was compiled for 103 Neolithic and Chalcolithic sites or levels from the Romanian Lower Danube region (Supplementary Material Table S4). The analysis integrated the values for grog frequency with chronological and chorological data into a geospatial model using kernel density estimation (or KDE; Baxter et al., Reference Baxter, Beardah and Wright1997; Sayer & Wienhold, Reference Sayer and Wienhold2013) within QGIS open source software. The density simulations were conducted at conventional ranges of 20, 50, and 100 km, the most relevant results being obtained at the 50 km range (see below). This approach allowed for a nuanced understanding of the origin, paths of diffusion, and prevalence of grog-tempered pottery across different temporal and spatial contexts.
Discussion
Emergence and dispersal of grog-tempered pottery in southern Romania
Given that chaff-tempered pottery dominated the Early Neolithic assemblages in the Middle and Lower Danube areas (Spataro, Reference Spataro2019), the emergence and gradual spread of grog-tempered ceramics beginning in the Middle Neolithic signifies a genuine technological change and innovation (Spataro, Reference Spataro2014). However, based on the data collected in southern Romania, grog-tempered pottery did not appear at the onset of the Middle Neolithic, as all pottery produced in the Dudești tradition (see Table 1 for chronology) was exclusively tempered with organic material (Comșa, Reference Comșa1987; Ștefan, Reference Ștefan2021). Our data suggest that the first use of grog occurred after 5300 bc, initially appearing in small quantities at Boian-Bolintineanu sites in central and northern Wallachia. Conversely, at another contemporary site in the same area, Chitila-Așezare, chaff tempering remained the norm and grog is absent. Towards the end of the sixth and the beginning of the fifth millennium bc, during the second phase of the Boian culture (Giulești), grog became more consistent, although its frequency remained low, ranging between 0.5 and 35 per cent, and it was often mixed with vegetal matter. This suggests a gradual and regionally variable adoption of grog-tempered pottery in southern Romania, reflecting the complex dynamics of technological innovation and diffusion at the end of Middle Neolithic (Figure 4).

Figure 4. Map of south-eastern Romania with locations of Middle Neolithic (c. 5400–4900 bc) sites with qualitative and quantitative data on pottery tempers expressed as pie charts (base map: https://maps-for-free.com).
Beginning in the Early Chalcolithic and continuing until the end of the Middle Chalcolithic, grog tempering appears to have been fully adopted by potters over a broad area between the Danube, the Carpathians, and the Black Sea, with the exception of the western region where chaff tempering was predominant and grog began to be frequently used only at the end of the Chalcolithic (Figures 5–7). In contrast to the Middle Neolithic, when chaff-tempered pottery was prevalent and the introduction of grog-tempered pottery was slow and gradual, the widespread use of grog tempering within Boian-Vidra sites during the first part of the fifth millennium bc signifies a substantial technological shift, corresponding to other major changes during this period, such as the emergence of tell-type settlements north of the Danube, the spread of early copper objects, pigments, and a diverse array of new objects of personal adornment made from exotic materials (Popovici, Reference Popovici, Anthony and Chi2010; Opriș et al., Reference Opriș, Velea, Secu, Rostas, Buruiană and Simion2022).

Figure 5. Map of south-eastern Romania with locations of Early Chalcolithic (c. 5000–4500 bc) sites with qualitative and quantitative data on pottery tempers expressed as pie charts (base map: https://maps-for-free.com).
These changes can be linked to a new wave of population coming from the south at the beginning of the fifth millennium bc, as suggested by genetic studies on limited samples (Hervella et al., Reference Hervella, Rotea, Izagirre, Constantinescu, Alonso and Ioana2015). This influx may have introduced different technological practices and contributed to the regional variability observed in the archaeological record. The core area of grog-tempered pottery north of the Danube was in southern and central Wallachia for almost the entire fifth millennium bc. This region is also suggested as one of the primary centres where the Kodjadermen-Gumelnița-Karanovo VI culture emerged in the early fifth millennium bc. From this core area, the culture spread east, west, and north, driven by rapid demographic growth (Popescu et al., Reference Popescu, Covătaru, Opriș, Bălășescu, Carozza and Radu2023). This suggests a strong correlation between the demographic dynamics and the spread of technological innovations, such as grog-tempered pottery, in the Lower Danube region during this period.
The second part of the fifth millennium bc marked the beginning of the decline of the flourishing Chalcolithic civilizations in the Lower Danube area. Within a few centuries, an almost two-millennium-long lifestyle ceased in the region (Reingruber & Thissen, Reference Reingruber and Thissen2009), although some enclaves remained resilient until the beginning of the fourth millennium bc (García-Vázquez et al., Reference García-Vázquez, Bălășescu, Vasile, Golea, Radu and Opriș2023; Popescu et al., Reference Popescu, Covătaru, Opriș, Bălășescu, Carozza and Radu2023). Based on the quantified data in this study, the use of recycled ceramics as pottery temper appears to have continued until the end of the Chalcolithic period (Figure 6), as observed in the final habitation layers at tell-type sites such as Sultana˗Malu Roșu and Aldeni-Gurguiul Balaurului.

Figure 6. Map of south-eastern Romania with locations of Middle Chalcolithic (c. 4600–3900 bc) sites with qualitative and quantitative data on pottery tempers expressed as charts (base map: https://maps-for-free.com).
The semi-quantitative data collected from publications further illustrate this picture, showing that the use of grog diminished during the Middle Chalcolithic in eastern Walachia and Dobrogea and that it was replaced by natural mineral tempers such as sand or pebbles. Meanwhile, grog tempering spread to the west, in an area where organic tempers had been predominant during the Middle Neolithic and Early Chalcolithic (Figure 7).

Figure 7. Heatmaps of grog-tempered pottery frequency in southern Romania generated by KDE at 50 km range (for data, see Supplementary Material Table S4). Cultures/phases: A) Dudești; B) Boian-Bolintineanu; C) Boian-Giulești; D) Boian-Vidra; E) Boian Spanțov; F) Gumelnița A1; G) Gumelnița A2; H) Gumelnița B1. Legend: red = predominant; orange = frequent; yellow = rare, green = very rare; no colour = absent.
Some thoughts on the emergence and spread of Neolithic grog-tempered pottery in south-eastern Europe
In Bulgaria, the examination of ceramics from several eastern Balkan sites indicates a clear predominance of chaff and an absence of grog in Early Neolithic assemblages (Spataro et al., Reference Spataro, Katsarov, Todorova, Tsurev, Nikolova and Yaneva2019; Dzhanfezova, Reference Dzhanfezova2021). During the Middle Neolithic, grog usage was minimal (Suvandzhiev, Reference Suvandzhiev2019), while in the Chalcolithic period, there were numerous mixtures of mineral tempers, with grog being used variably but never predominantly (Georgieva, Reference Georgieva, Stefanovich, Todorova and Hauptmann1998; Merkyte et al., Reference Merkyte, Albek, Sørensen Østergard and Zidarov2005; Chernakov, Reference Chernakov and Gurova2008; Parvanov, Reference Parvanov2021; Popova & Parvanov, Reference Popova and Parvanov2023). A comprehensive study focused on the evolution of cooking pots in present-day Bulgaria and Greece over five millennia (Dimoula et al., Reference Dimoula, Tsirtsoni, Yiouni, Chohadzhiev, Darcque, Ivanova, Valamoti, Ntinou and Dimoula2022) identified grog only in two Chalcolithic sites north of the Balkan Mountains, while south of the mountains grog was not a preferred temper during the Neolithic and Chalcolithic periods. All this scattered data highlights the variability and regional specificity of pottery tempering practices in the eastern Balkans, making cross-regional comparisons challenging.
In the search for the origins and dispersal of grog tempering, my attention shifted further to the west and north-west, encompassing the central Balkans, Serbian Carpathians, Banat, Transylvanian Plateau, and the Great Hungarian Plain, where data on pottery tempering is more plentiful (excluding Oltenia, where useful data are missing). By adopting a broader geographical perspective, it should be possible to gain a more comprehensive understanding of the technological transitions and cultural exchanges that influenced pottery production across these interconnected regions. Indeed, they witnessed radical changes in tempering practices during the late sixth and fifth millennia bc (Kreiter et al., Reference Kreiter, Pető, Pánczél and Bánffy2013; Spataro, Reference Spataro2014, Reference Spataro and Burnez-Lanotte2017; Hofmann, Reference Hofmann, Spataro and Furholt2020; Vuković, Reference Vuković, Spataro and Furholt2020).
The shift from organic to mineral tempering and the gradual emergence of grog-tempered pottery is evident in the Early Vinča assemblages from the central and western Balkans (Amicone et al., Reference Amicone, Mathur, Pavitra, Mirković-Marić, Pantović and Kuzmanović-Cvetković2020; Hofmann, Reference Hofmann, Spataro and Furholt2020), as well as the Transylvanian Plateau (Suciu, Reference Suciu2009; Spataro, Reference Spataro2014), within a timeframe ranging from 5350 to 5025 bc, a time that is partly contemporaneous with the slow introduction of grog in the Romanian Lower Danube area and the eastern Balkans. Given that a demographic shift and migration from the south is likely to have occurred during this period (Hervella et al., Reference Hervella, Rotea, Izagirre, Constantinescu, Alonso and Ioana2015; Porčić, Reference Porčić2020), one explanation for the change in pottery tempering in the central Balkans could be that these new trends were specific to, and gradually imposed by, putative southern newcomers. Indeed, mineral tempering was a common trait of the Middle and Late Neolithic assemblages in Thrace, Macedonia (Yiouni, Reference Yiouni1995; Fidanoski, Reference Fidanoski, Naumov, Fidanoski, Tolevski and Ivkovska2009; Saridaki et al., Reference Saridaki, Kostakis, Urem-Kotsou, Papadakou, Papaioannou, Amicone, Quinn, Marić, Mirković-Marić and Radivojević2019), and north-western Anatolia (Thissen, Reference Thissen, Roondenberg and Alpaslan-Roodenberg2008; Çilingiroğlu, Reference Çilingiroğlu2012; Peloschek, Reference Peloschek and Horejs2017), while chaff tempering was rare (unlike in the Middle and Lower Danube areas) (Papadakou et al., Reference Papadakou, Kotsakis and Urem-Kotsou2021). Grog-tempered pottery, on the other hand, is not noted as a particular characteristic in these regions. This suggests that one of the new trends in pottery technology that originated in the south during the second half of the sixth millennium bc involved replacing chaff tempering with mineral temper and that this became rapidly prevalent within Early Vinča assemblages (Spataro, Reference Spataro2014; Vuković, Reference Vuković, Spataro and Furholt2020). The introduction of mineral tempering provided a foundation for the development and adoption of grog, reflecting broader processes of technological adaptation and cultural exchange. Thus, while mineral tempering can be seen as a technical feature imported from the south, grog tempering is thought to represent a local invention within the pottery traditions of the Middle and Lower Danube area, signifying a dynamic interplay between external influences and indigenous innovation during the Neolithic period.
Based on the available data, there are at least two areas where grog-tempered pottery was gradually introduced between 5350 and 4800 bc: one in the central Balkans within the Early Vinča sphere, and one in the eastern Balkans and Romanian Plain within the Karanovo III–IV/Boian-Bolintineanu traditions (Figure 8). While there is insufficient data to link these two zones directly and trace the entire path of grog-tempered pottery introduction in the Middle and Lower Danube region, common southern influences on ceramic craft are discernible in both zones, especially among the widely distributed dark burnished wares and the clay figurines, evident in Vinča, Dudești, Boian-Bolintineanu, and Karanovo III–IV earthenware production (Neagu, Reference Neagu2003; Thissen, Reference Thissen, Roondenberg and Alpaslan-Roodenberg2008; Whittle et al., Reference Whittle, Bayliss, Barclay, Gaydarska, Bánffy and Borić2016).

Figure 8. Approximate spatial extent of grog-tempered pottery in south-eastern Europe during the Neolithic and Chalcolithic (dark orange = emergence areas; light orange = areas of spread), and the main sites associated with this tradition (dark orange = c. 5300–4800 bc; light orange = c. 4800–4300 bc) (base map: https://maps-for-free.com).
After this initial stage, the tempering of pottery with grog spread rapidly in the first part of the fifth millennium bc and during it, replacing chaff and becoming predominant in several regions across the Middle and Lower Danube area and further to the north-west and north-east (Figure 8). This dissemination is visible in various cultural traditions, including Late Vinča in Banat and Vojvodina (Tringham et al., Reference Tringham, Brukner, Kaiser, Borejević, Bukvić and Šteli1992; Mirković-Marić & Amicone, Reference Mirković-Marić, Amicone, Amicone, Quinn, Marić, Mirković-Marić and Radivojević2019; Amicone et al., Reference Amicone, Mathur, Pavitra, Mirković-Marić, Pantović and Kuzmanović-Cvetković2020; Hofmann, Reference Hofmann, Spataro and Furholt2020), Tisza, Herpály, and Lengyel in the Great Hungarian Plain (Kreiter et al., Reference Kreiter, Kalicz, Kovács, Siklósi and Viktorik2017, Reference Kreiter, Máté and Viktorik2022), Alföld Linear Pottery, Pișcolt, and Malice in the northern Carpathian Basin and Upper Silesia (Kadrow & Rauba-Bukowska, Reference Kadrow, Rauba-Bukowska, Pereira, Terradas and Bicho2017; Kadrow, Reference Kadrow, Furholt and Spataro2020; Rauba-Bukowska, Reference Rauba-Bukowska2021), Tiszapolgar in Transylvania and Banat (Diaconescu, Reference Diaconescu2009), Ariușd in the eastern Carpathians (Sztáncsuj, Reference Sztáncsuj2015), Pre-Cucuteni and Early Cucuteni in Moldova (Ellis, Reference Ellis1984, Reference Ellis, Spinei, Lazarovici and Monah2005; Marinescu-Bîlcu et al., Reference Marinescu-Bîlcu, Bolomey, Voia, Cârciumaru and Gâță2000), and Late Boian and Gumelnița in Wallachia, Dobrogea, and northern Bulgaria (Opriș et al., Reference Opriș, Lazăr and Ignat2017; Dimoula et al., Reference Dimoula, Tsirtsoni, Yiouni, Chohadzhiev, Darcque, Ivanova, Valamoti, Ntinou and Dimoula2022; Stoicescu et al., Reference Stoicescu, Duliu, Opriş, Manea, Mariş and Voinea2023).
The rapid spread of grog tempering in the fifth millennium bc over a huge area reflects not only the technological adaptability and innovation of its prehistoric communities but also the intricate web of interactions and exchanges. However, there remained some enclaves, such as western Wallachia, where chaff-tempered pottery predominated during the entire Neolithic and Early Chalcolithic periods, despite the shape and decoration of vessels being clearly influenced by broader cultural trends over time. A similar situation, with chaff used in isolation during the first part of the fifth millennium bc, exists in the Great Hungarian Plain and has been interpreted as the persistence of an Early/Middle Neolithic tradition over several generations (Gyucha et al., Reference Gyucha, Danielle and Kreiter2024). As for central Transylvania, mineral tempers were dominant during the Early Chalcolithic, but grog was present in small quantities in ceramics analysed by Opriș et al. (Reference Opriș, Bem, Dimache, Hila and Bem2015). This regional variability underscores the complexity of technological and cultural diffusion processes, highlighting how local traditions could persist even amid widespread technological shifts.
Function and social context of grog-tempered pottery
The gradual adoption and wide spread of grog-tempered pottery during the Neolithic and Chalcolithic periods as a pan-cultural technological tradition in the Middle and Lower Danube Basin requires some explanation. In contexts where similar behaviours have been noted, functional explanations have prevailed because they highlight the practical benefits of this tempering method, but social and symbolic features have also been recognized (Merkyte et al., Reference Merkyte, Albek, Sørensen Østergard and Zidarov2005: 85; Holmqvist, Reference Holmqvist2021).
From a functional perspective, it is well known that adding grog to the ceramic paste has several advantages. Grog helps prevent the formation of cracks during drying and firing and strengthens resistance to mechanical and thermal shocks (Rice, Reference Rice1987; Holmqvist, Reference Holmqvist2021). This increased durability would have made grog-tempered pottery particularly suitable for everyday use, cooking, and storage, which may explain its widespread adoption and persistence over time. Whatever the reason, in most instances no strong correlation between a vessel’s function and the presence of grog has been established. This suggests that the successful adoption of grog tempering was not solely influenced by function, and that we should consider social and symbolic explanations for the broader cultural implications of using grog-tempered pottery. The association between long-term tell-type settlements in southern Romania and grog tempering (Figures 5 and 6) may be an indication of a symbolic value carried by grog, which could include the ideological significance and social meaning of the object’s previous life (Holmqvist, Reference Holmqvist2021).
The selection of the same temper over many generations suggests that the choice was a product of cultural learning (Spataro & Meadows, Reference Spataro and Meadows2013), reflecting social identity, technological knowledge, and cultural traditions. These interpretations highlight that technological choices are often intertwined with social practices and cultural values (van der Leeuw, Reference van der Leeuw and Lemonnier1993). Social identity of the potters, as reflected in pottery tempers, is also emphasized by the continuity and resistance to change of the chaff tempering encountered in the western Walachian assemblages identified in this study.
Regardless of the explanation—whether functional, social, economic, symbolic, or more probably a combination of these factors—prehistoric communities that recycled old pottery as grog effectively removed a substantial part of their ceramic assemblages from the archaeological record. This practice of recycling pottery not only highlights the resourcefulness and sustainability of these communities but also poses challenges for archaeologists attempting to understand the full scope of ceramic production and usage in ancient societies.
Conclusion
This study provides an analysis of the development and dissemination of grog-tempered pottery in the region between the Danube and the Carpathians in a south-eastern European context. Initially produced towards the end of the sixth millennium bc during the Middle Neolithic, grog-tempered pottery became predominant in the Early Chalcolithic. Its distribution suggests a Balkan origin, with a gradual expansion to the north and east. Despite this spread, the core of this technological tradition remained in central and southern Walachia throughout the fifth millennium bc.
The persistence of grog as the main temper type at tell sites occupied over the long term, from the beginning to the end of their occupation (c. 500 years), reflects a strong local and regional tradition. Concurrently, the Early Neolithic tradition of tempering pottery with chaff continued into the Middle Neolithic and Early Chalcolithic in western Walachia, even though vessel shapes and decoration were shared with sites where tempering with grog was standard. The sustained use of specific recipes for making ceramics suggests population continuity in these areas, with clay preparation techniques being passed down through generations even as the aesthetic aspects of pottery changed.
The data gathered suggests that grog-tempered pottery across the Middle and Lower Danube regions began to be made in two initial core areas—in the central Balkans (Early Vinča tradition) and in the eastern Balkans and Wallachia (Karanovo III–IV and Boian-Bolintineanu traditions)—and that it then gradually spread throughout the fifth millennium bc, up to the northern Carpathians. As for the practice of ceramic recycling as grog, it attests to both advanced technological knowledge and significant social dimensions, including aspects of identity, kinship, and ancestry. Overall, this study illustrates the intricate interplay between technological innovation and social traditions in shaping the cultural history of our region.
Acknowledgements
This work was supported by a fellowship at the Research Institute of the University of Bucharest (ICUB) within the project ‘The rise and fall of the grog-tempered pottery in southern Romania during the Chalcolithic period (fifth millennium bc)’ (grant no. 6247/08.06.2023). I am grateful to Cătălin Lazăr, Dan Pîrvulescu, Theodor Ignat, Bogdan Manea, Valentina Voinea, Pavel Mirea, Raluca Iosipescu, Mihai Duca, Corina-Anca Simion, and Cristian E. Ștefan for access to unpublished pottery, new radiocarbon dates, logistical support, advice, and help. Notes on the article’s draft and further references to sites in Hungary were kindly provided by Attila Kreiter. The thin sections’ petrographic data from the Gumelnița assemblages were collected and interpreted by Daniela Dimofte. KDE tests and heatmaps were produced by my wife Ionela Opriș. I thank them all.
Supplementary Material
To view supplementary material for this article, please visit http://doi.org/10.1017/eaa.2025.4.