## 1 Introduction  
Coffee is one of the most complex beverages because it contains many non-volatile and volatile compounds generated during the brewing process. Non-volatile components of coffee are composed of carbohydrates, proteins, lipids, unknown melanoidins, minerals, and alkaloids such as caffeine, trigonelline, and chlorogenic acid [1, 2]. Non-volatile compounds degrade when they undergo thermal processing involving roasting. Chlorogenic acid and trigonelline are rapidly degraded during roasting, and phenolic compounds and pyridines/pyrroles are produced, respectively [3]. These newly formed compounds, along with other volatile compounds, influence the coffee quality or flavor. Recently, considerable research has been conducted on coffee volatiles, especially the volatile compounds in hot coffee from an espresso machine [4] and coffee that undergoes different degrees of roasting at varying temperature and time [5], using headspace solid-phase microextraction (HS-SPME)coupled with gas chromatography--mass spectrometry (GC--MS). Other studies related to specific coffee beans have also been conducted. [PERSON] et al. [6] explored the volatile composition of Arabica coffee, and [PERSON] et al. [7] identified five volatile compounds in a defective Brazilian coffee beans, which could be utilized to discriminate between defective and non-defective Brazilian coffee beans. Among the diverse types of volatile compounds in coffee, volatile thiols were studied by [PERSON] et al. [8]; they suggested that the amounts of volatile thiols in brewed coffee are affected by not only the innate amount in the coffee but also the extraction process. The variabilities in the volatile compound profiles of individual coffee beans were also analyzed [9]. [PERSON] et al. [10] studied the aroma profiles of roasted, ground, and brewed coffee. They used three varieties of Arabica coffee--El Salvador Bourbon, Ethiopia Kebado, and Hawaii Kona--as samples and three roasting processes, namely light, medium, and dark. Their research showed that both origin and roasting condition of coffee yielded different coffee flavors, especially \"burnt/acrid, pungent, ashy/sooty, and sour notes\". [PERSON] et al. [11] also showed that the grinding and extraction time influenced the sensory perception of Colombia (Huila and Narino) coffee samples. [PERSON] et al. [12] reported that the serving temperature, in addition to the grinding and brewing, was crucial to the quality of coffee. Six serving temperatures--31, 37, 44, 50, 56, and 62 \({}^{\circ}\)C--were used in this study. When compared with sensory data, 31-, 37-, and 44-\({}^{\circ}\)C coffee samples were related to the characteristics of sourness, tobacco, and sweetness, whereas higher serving temperatures--50, 56, and 62 \({}^{\circ}\)C--were related to the characteristics of bitterness, roasted, and overall intensity of coffee. They suggested that the serving temperature is related to certain volatile compounds that influence the flavor perception. According to [PERSON] et al. [13], the extraction method (cold drip, cold brew (CB) coffee) and temperature also affected the caffeine and chlorogenic compounds. Although diverse factors, such as the origin, roasting condition, grinding degree, extraction time, serving temperature, and extraction methods of coffee, were considered in these studies, research on the effect of brewing temperature on sensory perception related to non-volatile and volatile compounds in CB coffee is limited. Considering that the flavor and aroma of coffee are affected by each step of the coffee-production process, CB coffee may show different compositions of non-volatile compounds and volatile profiles compared to hot extracted coffee. Thus, the compositions of volatile compounds of various CB coffee types need to be further explored. Hot extracted coffee and CB coffee are considered to have different patterns of volatile and non-volatile compounds; thus, they should be compared.