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shoyu heat pasteurization (hi-ire)

process / process-shoyu-hi-ire

火入れ

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  2. Related entries (5)
  3. Sensory (1)
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Short definition

A soy-sauce production process that heat-sterilizes namaage shoyu obtained by pressing fermented and aged moromi. It is contrasted with 「生しょうゆ」 (nama-shoyu), which is not heated and is instead sanitized only by microfiltration.

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shoyu heat pasteurization (hi-ire) →increases→ bitterness →can be measured separately …→ astringency

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Sensory (1)

shoyu heat pasteurization (hi-ire) increases bitternesspreliminary

Scope: 6 brands each of commercial raw soy sauce and heat-treated (hiire) soy sauce (6 matched pairs from the same manufacturers), compared by QDA (quantitative descriptive analysis) with a trained panel of 13, women aged 32–62

Note: In Imamura & Katayama's (2017) QDA, heat-treated soy sauce showed significantly higher, or a differing tendency in, evaluation scores for bitterness, astringency/egumi, and bitter aftertaste compared with raw soy sauce (Wilcoxon signed-rank test). In the principal component analysis as well, bitterness, astringency/egumi, and bitter aftertaste showed strong positive loadings on PC1 (0.95, 0.94, and 0.93 respectively; 69.3% contribution rate), and heat-treated soy sauce was plotted in the positive direction of PC1. Note that this is the heat-sterilization process itself, not a change in the fermentation process. 2026-10-21 (expansion stage N5, stage C, batch 3): in Table 3 only bitter aftertaste reached p<0.05 (1.7 vs 1.2, p=0.031); bitterness (1.9 vs 1.5) and astringency/egumi were trends at p=0.063. The comparison is of 6 pairs of different commercial products with no heating conditions given, so the status was lowered from supported to preliminary.

Verbatim (a sentence combining the p<0.05 differences and the p<0.1 trends of Table 3): 「火入れしょうゆでは，刺激臭や漬け物のにおい，昆布だしのにおい，豆味噌のにおい，塩味，酸味，苦味，渋味・えぐ味，苦味の後味，コゲ風味，消毒薬の風味，金属の風味およびピリピリが強いことを示した」 (in translation: "heat-treated soy sauce showed stronger pungent odor, pickle odor, kelp-dashi odor, soybean-miso odor, saltiness, sourness, bitterness, astringency/egumi, bitter aftertaste, burnt flavor, disinfectant flavor, metallic flavor, and tingling"). In Table 3, bitterness (1.9±0.2 vs 1.5±0.3) and astringency/egumi (1.8±0.2 vs 1.5±0.3) were p=0.063 (a trend), and bitter aftertaste (1.7±0.2 vs 1.2±0.3) was p=0.031. In the principal component analysis (variance-covariance matrix), the loadings were bitterness 0.95, astringency/egumi 0.94, and bitter aftertaste 0.93 (PC1, 69.3% contribution rate); heat-treated soy sauce was plotted in the positive direction of PC1 except the heat-treated product of company D (raw soy sauce in the negative direction except companies E and F).
Limitations: The products are separate commercial products paired by maker. Products with as few ingredients other than soybean, wheat and salt as possible were chosen, but Table 1 includes brands with defatted processed soybean, alcohol or mirin, and they do not necessarily represent all commercially distributed soy sauce. The heating temperature and time of each product are not given. This is an intensity evaluation by a trained expert panel, not a preference evaluation by ordinary consumers. Bitterness and astringency/egumi are a trend at p=0.063; p<0.05 applies to bitter aftertaste and others.
Source: 定量的記述分析法による市販の生しょうゆと火入れしょうゆの評価および日本のしょうゆの特徴の体系化 (今村美穂; 片山弘, 2017) · full text checked
Show dataprocess-shoyu-hi-ire —increases→ sensation-bitter
claim: clm-shoyu-hiire-increases-bitterness / type: sensory / updated: 2026-09-01

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