【赤紫蘇の塩もみ】発酵しば漬けで徹底検証・アク抜きの常識が覆る！

Is salting (removing bitterness) red perilla leaves really necessary? We tested the necessity of removing bitterness by making lactic acid fermented pickled vegetables using red perilla leaves prepared with different methods. [Table of Contents] 00:00 Opening 00:29 How to Make Rubbed Shiso: Preparation 02:03 How to Make Rubbed Shiso: Rubping 04:51 Preparation and Conditions for Shibazuke 06:21 Adding Rubbed Shiso with Vinegar 07:21 Fermentation Completed and Verification 10:16 Ranking 12:19 Summary [How to Make Rubbed Shiso] ■ What you need Red shiso leaves: Appropriate amount (weigh during the process) Salt: 20% of the weight of the red shiso (Example: 200g salt for 1kg of shiso) Vinegar: 50% or more of the rubbed shiso (at least enough to coat the entire shiso) Storage jar: Appropriate size (no prior sterilization required) ■ Process 1: Preparation (Selection and Washing) ① Selecting the leaves Pick the leaves from the stems. The long, slender part at the base of the leaf (petiole) can be left attached, but remove any that are greenish. ② Washing (2 times) Immerse the shiso leaves in plenty of water and gently rub them together to wash away any dirt. Repeat this process twice. ③ Draining and Weighing Roughly drain the water and do a final check for any remaining dirt or stems. Then, weigh the leaves and calculate the required amount of salt (20%). ■ Step 2: Salting ④ First Rub: Breaking Cells with Pressure Sprinkle half of the prepared salt over the shiso leaves. While spreading the salt evenly, rub the leaves vigorously, applying pressure as if "crushing" them, to physically break down the shiso cells. Water will gradually start to come out, and when water begins to accumulate at the bottom of the bowl, the first rub is complete. Squeeze the shiso leaves firmly with both hands and discard all the released water. ⑤ Second Kneading: Distributing Salt Evenly Add all the remaining salt that has formed clumps after squeezing, and loosen the shiso leaves. For the second kneading, do not apply strong pressure, and mix gently to distribute the salt evenly among the loosened shiso leaves. If the salt becomes difficult to dissolve, lightly knead the shiso leaves with minimal pressure, using the released moisture to dissolve the salt. The process is complete when the salt grains are no longer visible. Squeeze firmly again and discard all the released moisture. ■ Step 3: Preservation ⑥ Bottling To make it easier to use later, break up the clumped shiso leaves into smaller pieces and place them in a preservation jar. (※Since shiso leaves themselves are full of bacteria, sterilization of the jar is considered unnecessary.) ⑦ Adding Vinegar Pour vinegar into the jar. The amount should be at least 50% of the volume of the kneaded shiso leaves, but it is not necessary to measure precisely; it is sufficient if the vinegar coats all of the shiso leaves. ⑧ Storage: Close the lid and store in the refrigerator. [Summary of this test result] What is the "bitterness" of red perilla? The term "bitterness" is inherently vague and convenient. It's used to refer to various things, such as the "toxins" in bracken, the "off-flavors" in konjac, and the "discoloration (polyphenols)" in eggplant. In this test, no bitterness was detected in the red perilla; in fact, the aroma was stronger without the "bitterness removal" process. Why is red perilla rubbed with salt? Removing moisture with salt and then soaking in vinegar increases its shelf life. We speculate that this traditional practice of treating the rubbed perilla with a large amount of salt and soaking it in vinegar, not only to improve the shelf life of the rubbed perilla itself but also to prevent it from hindering the shelf life of other products using the rubbed perilla, such as pickled plums, eventually came to be called "bitterness removal." Is "salt rubbing" necessary for red perilla used in making shibazuke? If long-term storage is the goal, like with pickled plums, then salt rubbing with a high salt concentration is necessary. However, in the case of "shibazuke" (pickled eggplant), the saltiness from the rubbed shiso leaves makes the whole dish too salty, and the time required for lactic acid fermentation also increases. Therefore, if you are not planning on long-term storage, you can make delicious shibazuke without salting the shiso leaves, and if you are not planning on long-term storage of the red shiso leaves, you may want to adjust the amount of salt used for salting. If color is important, adding the stored rubbed shiso leaves to the pickles after the first fermentation will give them a beautiful purple color. ★ Conclusion If long-term storage (several years at room temperature) or color development is not the goal, it is better not to remove the bitterness from the red shiso leaves (salt them) for a tastier result. (At least in this experiment) 【Selected Ingredients for This Experiment】 　Red shiso leaves from Aichi Prefecture (very high quality) 【P...