So far, we outlined the trade-off between a satisfactory experience and efficiency that comes with deciding for or against automation. The Hotzenplotz grinder (section 2.3.) attempts to reconcile this apparent contradiction between meaning and efficiency. It is a hybrid to combine the best of both worlds. In study 2, we tested Hotzenplotz “in the wild.” We sought to explore whether promising previous findings transfer to everyday coffee grinding in real life. Based on our previous results, we expected Hotzenplotz to provide a richer experience, specifically in terms of stimulation and competence. We also expected a more positive affective experience with Hotzenplotz. In the present study, we further complement quantitative findings with an extensive qualitative investigation. Through this mixed method approach, we provide not only a holistic view, but also a detailed perspective on experiences of using a hybrid coffee grinder in everyday life.
Participants and procedure
In this two-week study, the grinding process as a sub-process of “coffee-making” was subject of the investigation. Eight individuals participated in the study (6 female, median age = 30, min = 27, max = 50; see Table 3). They had diverse backgrounds, such as civil engineer, psychotherapist and being students. They received no compensation for participation. Moreover, the participants did not know the exact aims of the study. Before the study, participants signed a data privacy declaration. Each of them was provided with each of both grinders (Hotzenplotz and automatic grinder TZS Millard, see Fig. 4) for 1 week in a counterbalanced order. Besides the grinders, we provided the participants with coffee beans and a French Press coffee maker.
In each condition, participants were briefly introduced to the respective grinder (see Fig. 4) and the French Press coffee maker. We asked them to make coffee using the provided tools over the course of 1 week. After each interaction with the grinder, but before brewing the coffee with the coffee maker, the participants were instructed to fill in an online questionnaire via their smartphones.
The questionnaire contained two items about how positive and negative participants felt during coffee grinding (both on a 7-point Likert scale from 1 = “not at all” to 7 = “extremely”). Then, we measured focus on the task by asking in how far they were concentrated on the grinding process and included another question about whether they would have liked to prolong the process, both with the same 7-point scale. Finally, we measured psychological need satisfaction using the same scales as in study 1. Additionally, we measured subjective product quality using the AttrakDiff Mini . This questionnaire assumes two different, broad categories of perceptions: hedonic and pragmatic. Pragmatic quality refers to a product’s perceived potential to support particular “do-goals” (e.g., to make a telephone call). In contrast, hedonic quality refers to a product’s potential to support pleasure in use and ownership, that is, the fulfillment of psychological needs (e.g., to be stimulated). The AttrakDiff Mini includes nine seven-point semantic differential items, four of which capture pragmatic quality: simple–complicated, practical–impractical, predictable–unpredictable, and clearly structured–confusing. Four more items captured hedonic quality: stylish–tacky, premium–cheap, creative–unimaginative, and captivating–dull. In addition, we measured general goodness (good–bad) and beauty (ugly–beautiful) with a single item each. Internal consistencies were all satisfactory (see Table 4).
After each week of using one of the two grinders, we carried out a semi-structured interview to get a deeper understanding how each grinder was experienced and integrated into daily routines. At the beginning of the interview, we asked how the participants experienced the grinder in general, and we particularly asked for positive and negative moments. Then we asked if they would have liked to prolong or shorten the interaction, or if it just felt right. To continue, we asked about the experiences of need satisfaction, such as competence, stimulation, and autonomy. Furthermore, we asked the participants to describe the interaction in detail. Finally, end, we asked about the meaning attributed to the grinding itself. All interviews were audio- and video-recorded and later transcribed.
Similar to study 1, we used the aggregated means of all coffee grinding instances per participant and condition. For instance, if one participant used one of the grinders five times, we aggregated the five values from the 5 filled-in questionnaires into a single value that we used for our data analysis. In order to control for a novelty effect with Hotzenplotz, we excluded the first 3 days of the Hotzenplotz condition for all calculations except for the frequency of use. Two participants used Hotzenplotz only during the first 3 days and were thus excluded from these analyses.
Frequency of use
In total, the eight participants grinded coffee beans 99 times over the 2 weeks, 40 times (40%) with Hotzenplotz. This amounts roughly to one grinding per day and per participant, slightly less with Hotzenplotz compared with that of the automatic grinder. We compared the frequency of use for both machines by running a two-way ANOVA (2 × 2) with the within-participants factor “grinder” and the between-subjects factor “order of usage.” Our dependent variable was the number of grinding per condition. We found only a significant main effect for “grinder” (F(1, 6) = 10.46, p < .05, η2p = .64), indicating that participants used the automatic grinder (M = 7.37; SE = 1.25) more often than Hotzenplotz (M = 5.13; SE = 1.19), independent of the “order of usage.”
Unlike the previous study, we did not include the PANAS this time in order to keep the questionnaire reasonably short. Thus, affect balance was calculated as the difference between the questions about positive and negative feelings during grinding. A 2 × 2 ANOVA with the within factor “grinder” and the between-factor “order of usage” revealed no significant main effect of “grinder” on affect balance, F(1, 4) = 1.84, p = .12, η2p = .32. No other effect was significant.
Next, we compared the effect of the grinding process on “focus.” A similar 2 × 2 ANOVA with the measure “focus” revealed a significant main effect for the factor “grinder” (F(1, 4) = 18.81, p < .05, η2p = .83), indicating that participants were more focused on the grinding process, when using the Hotzenplotz (M = 4.97; SE = 0.31), compared with the automatic machine (M = 2.68; SE = 0.57). No other effects were significant.
Willingness to spend more time grinding
Moreover, we looked at the willingness to spend more time grinding coffee with the respective machines. Using the question whether participants would have rather lengthened the process as our measure, a similar 2 × 2 ANOVA revealed no effect for “grinder” (F(1, 4) = 3.38, p = .07, η2p = .46), and no other effects were significant.
Concerning need fulfillment, we ran a 6 × 2 × 2 mixed ANOVA with the within-factors “needs” and “grinder” and the between-factor “order of usage.” We found a significant main effect for “grinder” (F(1, 4) = 7.76; p < .05; η2p = .66), indicating that Hotzenplotz (M = 3.24; SE = 0.30) allowed for a more fulfilling experience than the automatic grinder (M = 2.51; SE = 0.25). Moreover, we found a main effect for “needs” (F(5, 20) = 4.66; p < .01; η2p = .54) and an interaction effect of “grinder” and “needs” (F(5, 20) = 3.22; p < .05; η2p = .45).
No other effect was significant. All needs were more fulfilled when using Hotzenplotz with the exception of security. Based on our previous findings in the lab, we ran two separate 2 × 2 ANOVAs with the factors “grinder” and “order of usage” for stimulation and competence, respectively. We found a significant main effect on the factor “grinder” for “stimulation,” which was higher in the Hotzenplotz condition (M = 3.77; SE = 0.32) than in the automatic condition (M = 2.48; SE = 0.24; F(1, 4) = 10.77; p < .05; η2p = .73). Moreover, we found a significant main effect for “competence,” which was also higher in the Hotzenplotz condition (M = 2.98; SE = 0.38) than in the automatic condition (M = 2.07; SE = 0.17; F(1, 4) = 7.80; p < .05; η2p = .66). Both effects confirm our previous findings from the lab. No other effects were significant in either ANOVA.
Similar to the previous lab study, interaction with Hotzenplotz was experiences as more fulfilling than the automatic grinder. Specifically, it was more stimulating and made the participants feel more competent.
The AttrakDiff Mini contains a scale for perceptions of hedonic quality, one scale for perceptions of pragmatic quality and one item each for general evaluation (i.e., goodness) and beauty. Concerning hedonic quality, a 2 × 2 ANOVA with the within factor “grinder” and the between-factor “order of usage” revealed a main effect for “grinder” (F(1, 4) = 17.18, p < .05, η2p = .81), indicating that participants attributed a higher hedonic quality to Hotzenplotz (M = 5.42; SE = 0.48) than to the automatic grinder (M = 3.08; SE = 0.18). No other effect was significant. A similar 2 × 2 ANOVA for pragmatic quality revealed no difference between the two grinders (F(1, 4) = 0.83, p = .42, η2p = .17), and no further effects. In terms of “goodness,” a 2 × 2 ANOVA revealed a main effect for “grinder” (F(1, 4) = 8.47; p < .05, η2p = .68). Hotzenplotz (M = 5.94; SE = 0.38) was perceived as better than the automatic grinder (M = 5.09; SE = 0.39). No other effect was significant. For “beauty,” the assumption of normality was violated, which is why we opted for the non-parametric Wilcoxon test with the factor “grinder.” Hotzenplotz was perceived as more beautiful (Mdn = 6) than the automatic grinder (Mdn = 3.17, z = − 1.99; p < .05; r = − .58).
Summary of quantitative findings
In sum, the quantitative data from study 2 revealed experiential advantages of Hotzenplotz when compared with the automatic grinder. These advantages stem from experiences of competence and stimulation. Although need fulfillment was higher, this was not mirrored in measured affect. We attribute this to the reduced affect scale and the small sample. However, hedonic quality, goodness, and beauty measures all indicated that Hotzenplotz was perceived more positive than the automatic grinder, with its pragmatic quality still intact. Thus, Hotzenplotz was successful in reconciling experience and pragmatic aspects, such as efficiency.
In general, within the Hotzenplotz setting, fewer negative experiences were mentioned (16 of 147, 11%) compared with positive ones (131 of 147, 89%). In the electric grinding condition, mentioned were more negative (78 of 144, 54%) than positive (66 of 144, 46%). For the remaining analysis, we focused on the positive experiences. Our analysis consisted of two elements to provide both, a holistic and an in-depth understanding of the interview data, that is, we looked at “both the forest and the trees” (, p. 223). We first focused on details, using the sub-coding method [19, 20], which was later followed by a synthesis and reflection.
Positive experiences and meaning
We first structured our interview data using the sub-coding method [19, 20]. This starts with inductively creating top-level categories (“creation process,” “grinder,” “preferences”) followed by a re-classification of the codes, if applicable, to more and more detailed sub-codes. This resulted in three “code-families,” which we mapped in a hierarchical diagram, allowing for a structured overview (see Fig. 5).
At first glance, Fig. 5 shows that the Hotzenplotz grinder (yellow dots) is represented more frequently than automatic grinder (blue dots), due to the higher proportion of positive comments it received. In the following, we analyzed the three “parent categories” and the differential, underlying mechanisms for the two grinders following the broad structure of the hierarchy.
The “creation process,” which represents the actual interaction with the grinder, i.e., to turn beans into coffee powder, was appreciated in both grinders (65 positive mentions with Hotzenplotz, 23 with the automatic grinder). In general, comments were more focused on the “interaction” than the “outcome” given the focus of our interviews. The participants enjoyed being part of the process with both grinders. While “transparency” (i.e., having an idea of what is going on in the grinder) was seen as about equally positive with both grinders, positive mentions about “control” (i.e., having an influence on the grinding process) were almost exclusively related to Hotzenplotz.
Looking at “transparency” in more detail, we found that sensory feedback, such as the smell, the sound of the beans hitting the glass cylinder, or just watching them turn into coffee powder were seen as positive. Also, haptic feedback, i.e., the vibration of the grinder, was perceived positively. P7 reported that she liked the experience with all her senses: “The sound is definitely nice. How the beans get smashed against the glass. I liked this […] it was fun to see the beans flying high and to see how they were turned into coffee powder.”
In terms of “control,” there were very few comments on the automatic grinder, essentially relating to portioning, i.e., being in charge of measuring and readjusting the amount of beans to be ground. In contrast, Hotzenplotz produced positive feedback in more diverse subcategories. Participants enjoyed being in control of the grinding speed, using the crank, and, similar to the automatic grinder, the portioning.
These facets of control were directly related to as well as enhanced by the transparency: Controlling the speed enabled the participants to control the loudness of grinding, a major negative point in study 1. Cranking gave them a direct connection to the grinding process, enabling them to feel the motion and to observe the beans transform into powder. Portioning, in both conditions, provided haptic and visual feedback and offered a certain autonomy. For the automatic grinder, one participant (P6) said: “I did [prepare] it in my own way, because I could decide on the amount [of coffee beans].” For Hotzenplotz, a representative comment was: (P2) “[…] it was important to me to control it [the grinding], probably that meaning is a bit too much, but [it was important for me] to know that every step is reasonable.” All in all, by increasing control, our participants felt that they were part of the grinding process when using Hotzenplotz, even though they were supported by the semi-automated, effortless grinding interaction. This feeling was less prominent with the automatic grinder.
The outcome (fine coffee powder) was mentioned positively slightly more often with the automatic grinder and was mainly related to efficiency, since the participants could do something else in the meantime and were not focusing on the process as much.
The smallest coding family related to the form of the “grinder.” Given that we asked mostly about the interaction, we had only a few positive comments about the device itself. A few participants reported the “formal esthetics” of Hotzenplotz as positive. P3 reported “regarding the optics, it was an eye-catcher for everyone entering my office”; P5 liked that Hotzenplotz suited the home context: “I liked about the machine that is was looking incredibly good, and it suits my kitchen in a nice way. I found this very positive.” No participants reported positive statements about the formal esthetic of the automatic grinder.
The third coding family related to aspects of “user preference,” i.e., how the grinder matched their overall lifestyle, how they reflected about using the grinder, and time-related attitudes. Generally, Hotzenplotz was positively mentioned in all three categories, while comments about the automatic grinder mainly related to time attitudes and reflection.
When users reflected about using the automatic grinder, they mainly thought about the freshness of the coffee powder. Unlike readily ground and packed coffee from the supermarket, the grinder allowed them to produce the coffee powder just before they made their coffee, which also triggered the anticipation of the coffee as a side effect. For instance, one participant said: (P4) “That was definitely part of the indulgence […] that’s why I grind the coffee beans or let them be ground […] yes, it is also absolutely about the freshness. I mean freshly ground coffee is delicious.” Moreover, Hotzenplotz facilitated communication with other people, such as guests, colleagues, or flat mates. As one participant put it: (P3) “Yes, one could easily start a conversation about the grinder.” Hotzenplotz added further facets of meaning, such as cultural/social status through its character as an “eye-catcher,” a raised awareness of ceremony for guests, or other people the coffee was prepared for. One person described it like this: (P3) “The rituals, which depend on daytimes, I have anyway, but this is an additional bonus, because coffee will be served and I made it.” For some people it also triggered nostalgic feelings about their past, associated with harmony and coziness. Finally, the more varied interaction with Hotzenplotz served the participants’ curiosity.
Although we had time-related comments for both grinders, the specifics were quite different. The automatic grinder elicited comments mainly about efficiency or optimization. For example, one participant said: (P5) “It is an operation you don’t need to pay attention to. When you start it once you can do something else in parallel, because you don’t need to take care of the machine. That’s quite practical.” Thus, it is valued particularly when time is scarce. In that regard, one participant (P7) stated “The electric one is very useful in the morning, because you will receive freshly ground coffee.” The picture was very different for Hotzenplotz. Participants wanted to “take time” for the process and to have the positive experience last longer compared with the automatic grinder. One participant said: (P5) “One has to make sure to portion the right amount of coffee for a Bialetti, because it is just a small amount. I would love to prolong the interaction.” And another one stated (P1): “Usually I thought I would love to crank longer, even if I did not need so much coffee, but that was really nice.”
Finally, positive comments relating to “lifestyle” and the ability to integrate the grinder in one’s personal daily routines were fewer for the automatic grinder than for Hotzenplotz. With the automatic grinder, positive experiences mainly related to the character of a “happening.” As one participant put it: (P4) “Yes, it was still something special. At some point it might turn into an everyday thing, when I might think ‘coffee-grinding – I don’t mind’ But after one week it was still a happening.” A few comments also described it as some sort of a “ritual,” especially in the morning, in spite of the stress. The automatic grinder could showcase its strengths as an efficiency-optimized device. One user said: (P4) “Of course it was fun, because everything worked out so fast. Actually, I didn’t need to do anything […] I liked that I could do something else in the meantime.” The efficiency might be a basic requirement to allow participants to squeeze their ritual in because it abbreviates it.
In contrast, the Hotzenplotz raised more diverse positive comments about the integration in daily routines. Mainly participants reported that the Hotzenplotz provides a magical moment during the grinding process, which leads to a “positive surprise.” Some participants also reported that they took their time for a beloved “ritual” in the morning to start the day or in the afternoon to have a break. Through the various possibilities of changing the final coffee powder in its consistency, participants were motivated to reframe coffee grinding as an “experiment”: (P2) “One might experiment a bit and what happened, might not be expected before, because this is not an “ordinary” coffee grinder and that is great fun. You look through into the glass cylinder and see how the coffee beans swirl around and you see how fine the powder already is during the grinding.”
Summary of qualitative findings
In the first part of the analysis, we presented the detailed characteristics of both grinders as experienced by the participants in three different coding families: the “creation process” is based on the interaction with the grinder during the grinding of the coffee beans, the coding family “formal esthetics” describes how the outer appearance leads to positive experience and as the last coding family the user’s “preferences,” which describe an individual way how the participants interacted with the grinder (see Table 5 for a further overview). All of those coding families had particular sub-practices, which we defined based on Shove et al.’s  social practice theory. Here, a social practice consists of three elements: The most abstract element is the meaning, which could be better described as a particular aim to perform the practice. Klapperich et al. [22, 23] define meaning further with the satisfaction of basic psychological needs such as stimulation, being competent, acting autonomous, feeling popular or having positive feelings of being secured by rituals. The performance of the practice is based on the practitioner’s competences, which are needed to perform the practice. And those competences are always supported by a specific material, which could be a tool or an object. In Table 5, it is demonstrated how these three elements are interconnected with each other and if for instance the material is changed, the practice may also change through the transformation of the competences and the meaning of the practice.
The “creation process” consisted of positive experiences of the interaction and the outcome of the coffee grinding. In both conditions the sub-practice of “observing” and “portioning” occurred. Here, “observing” was in both ways connected with a similar material: the transparent bean-reservoir (automatic grinder) and the glass cylinder (Hotzenplotz grinder) allowed the user to understand what was going on inside the machine.
The automatic grinder gave an insight how the beans were transported to the grinding mechanism through the bean-reservoir. At the Hotzenplotz grinder, the glass cylinder allowed a view on the grinding mechanism itself and also showed in detail how the coffee beans were ground, which might be the reason for more transparency and a higher stimulating effect. The sub-practice of “portioning” was comparable in both conditions as well through a similar material (powder container and glass cylinder), which could be seen as an option to be in the loop of the process by using the materials as a tool to portion the right amount of coffee powder, which led to a feeling of being competent.
The main difference was the sub-practice of “cranking” during the grinding process with the Hotzenplotz. Here, an interplay between the desired fineness of coffee powder through the “observing” occurred while turning the crank; this made the participants part of the process and created a feeling of competence and autonomy.
To sum up, the automatic grinder was appreciated for its ability to create standardized high-quality coffee powder. Even though participants only played a limited role in grinding, they appreciated the smell and haptic experience (transparency). In addition, Hotzenplotz was experienced positively because it allowed for a greater degree of control. The interaction with the crank, control of the speed, and portioning were seen as positive.
Regarding the formal esthetics, the unusual form of Hotzenplotz left a positive impression with its users and integrated well in the environment. There were no particularly positive mentions about the form of the automatic grinder. Here the sub-practice of “presenting the grinder” occurred, which was connected to the material, by using valuable and natural materials and created a sense of popularity by inspiring others.
Differences in lifestyle or usage scenarios were captured in the “user preferences” coding family. Both devices had their respective advantages depending on the context. Participants reflected on the automatic grinder as deriving its meaning by making fresh coffee beans easily accessible without needing much care otherwise. We described the sub-practice as “efficient brewing,” which could save time. Here, the material is a high-speed grinder which saves time and could be thereby filled in compressive designs. This kind of efficiency could be seen as a basic condition to have a beloved coffee ritual in the morning, which creates a meaningful moment through security. In a similar vein, the Hotzenplotz created a sub-practice, which we called “ceremony”: The material of the practice (glass cylinder/crank) is designed to make time to celebrate this delightful moment; the meaning behind this is to take time for having a coffee ritual which is making users feel secure. “Valuing raw-material” as a sub-practice occurred in both conditions through the similar process, of choosing the coffee beans autonomously and filling them into the grinder and then not losing the connection with the material until further processing.
In contrast, the Hotzenplotz grinder created more diverse sub-practices through its specific design: the grinder motivates the user to “be curious” and start “experimenting” with the Hotzenplotz, because of the combination of the glass cylinder, and the crank the user always has the feeling of being in the loop, which helps to support an autonomous handling, but also to grow knowledge about coffee grinding itself. Participants also often reported the practice “positive surprise,” because they still had something to discover, which made them feel more stimulated.
In conclusion, both grinders served as a topic of conversation. Hotzenplotz represented a certain nostalgia, while being a unique eye-catcher that was associated with social status. Some users were willing to spend more time on the Hotzenplotz grinding process, because it was meaningful to them and it became a joyful moment in their daily routine.
Synthesis and reflection of study 2
For this section, we reintegrate the detailed facets within the coding families (“creation process,” “grinder,” and “user preferences”) to draw a picture of how these details blend together in overarching scenarios. As a compound concept, social practices can be designed through intentional interconnections of their three elements: material, meaning, and competences [21, 23]. We summarize and outline somewhat idealized practices for both modes of coffee-making, integrating the findings from the previous analysis, before briefly reflecting on each.
Integration through efficiency
Coffee is an important ingredient in the daily routine of busy workers: It literally fuels the knowledge economy. While people appreciate the good taste and high quality of freshly ground beans, they have little time in the morning before leaving the house, often taking their coffee with them. Efficiency is key and the coffee grinder needs to fit in optimized, condensed morning routines. The coffee itself is important, which is reflected in the number of comments on smell and the standardized, reliably good coffee. Additional cues such as the sound of grinding beans and visual feedback, as well as the possibility to portion just the right amount of beans, serve as an ambient assurance that everything is going as planned and underlines the positive anticipation of a tasty coffee, while the thoughts of the busy user are already focused on other, more important things. The grinder itself stands back; it is less important than the coffee it produces. Its visual appearance is therefore less important.
Later, on the way to work, people enjoy the coffee, appreciate its freshness, and take some pride in still having at least contributed al little to its production.
While this scenario seems to be already covered by fully automated coffee makers, we found that a light, manual gesture, such as the portioning in our case, can provide additional value. We learned from the interviews that users appreciated this basic element of control, even if they were focused on efficiency. We think that a concept of “ambient” coffee-making that happens in the background, but is not completely hidden, opens up an interesting field of development, that may focus on sensory feedback supporting appreciation of the coffee while leaving the user with the freedom to take care of other things.
Integration through need satisfaction
Coffee also represents leisure and social pastime. When taking a break, or as a ritualized practice in the afternoon, the competent home barista needs full control of each step in the preparation process, but does not want to be bothered with unnecessarily exhausting interactions that only distract from the important things. Hotzenplotz provides direct control of the mill with a naturalistic crank, which allows for perfect, “handmade” coffee powder and augments the interaction in a nearly magical way. While grinding, visual cues of the fineness of the powder, its smell, and the haptic feedback of the supporting engine are necessary to exercise that control and offer the stimulating experience that turns a user into a barista. All of this takes place before the coffee is ready for the next step. At times, one of the biggest challenges during grinding for the users is to let go of the enjoyable activity when the coffee is right, because they are so focused on the process and tend to forget the importance of the outcome. Of course, when friends come to visit, they expect nothing less than the perfect blend from their personal coffee expert, and are charmed by the mysterious, eye-catching grinder that expresses value and high quality. When finally drinking the coffee, the curious device often serves as a starting point for engaging conversations.
On the other side of the scale, traditional manual grinders occupy the space. In our field study, however, we found that the “automated from the bottom” Hotzenplotz augments this experience by reducing effort, while leaving or even extending the sensory experience. We learned that cautious automation of unpleasant sub-steps, such as turning the grinder, while preserving or even extending the positive ones, e.g., through visual feedback, created positive experiences that transferred to the participants’ everyday lives. The direct contrast with an automated grinder invited them to think more consciously about their coffee routines.