Investigation of extraction phenomena in continuous circulation coffee brewing and comparison with other brewing methods
Bibliographic record
Abstract
Abstract This study investigated a continuous circulation cold brewing (CCCB) process using a modified single‐serve brewer that allowed recirculation of the brew within the single‐use capsules. The changes of total dissolved solids (TDS), titratable acidity (TA), caffeine and 5‐caffeoylquinic (5‐CQA) concentrations over time during the CCCB process were evaluated using two masses of coffee grounds (10 and 12.5 g). To elucidate the extraction process, Weibull distribution, pseudo‐first order, and pseudo‐second order models were fitted to the extraction kinetics data. The physicochemical quality of the brews produced from the CCCB process were also compared to brews produced though traditional cold brew steeping (separated by gravity and forced filtration) and single‐serve hot brewing processes. Significantly lower ( p < 0.05) TDS, TA, and 5‐CQA concentrations than traditional cold brew methods were observed. This observation was due to flow channeling/detachment phenomena in the coffee bed which resulted in localized flow and reduction of coffee‐water contact area. In comparison, the 30 min full immersion processes resulted in approximately 70% of the TDS, TA, and caffeine levels during the first 30 min of brewing, suggesting that cold brewing processes may not have to be >8 h in length if these are the targeted brew quality indices. Practical applications This study examined the kinetics and physicochemical quality of continuous circulation cold brewing of coffee and compared it to traditional full immersion cold brewing methods. The findings in this study indicated that: (1) The brew recirculation method explored was not on par with traditional full immersion cold brewing methods in terms of extraction yield due to flow channeling issues present in single‐use capsules; (2) The extraction time of traditional cold brewing processes can potentially be shortened on the basis of TDS, TA and caffeine content; (3) The choice of filtration mechanism is significant when considering the extraction yield of a brewing process.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".