{"id":3475,"date":"2026-10-09T03:08:46","date_gmt":"2026-10-08T19:08:46","guid":{"rendered":"http:\/\/www.primamahamaju.com\/blog\/?p=3475"},"modified":"2026-10-09T03:08:46","modified_gmt":"2026-10-08T19:08:46","slug":"does-mushroom-soy-sauce-need-to-be-filtered-during-the-making-process-4359-e79b75","status":"publish","type":"post","link":"http:\/\/www.primamahamaju.com\/blog\/2026\/10\/09\/does-mushroom-soy-sauce-need-to-be-filtered-during-the-making-process-4359-e79b75\/","title":{"rendered":"Does mushroom soy sauce need to be filtered during the making process?"},"content":{"rendered":"

Hey there, so I\u2019ve been in the mushroom soy sauce game for over a decade\u2014my small-batch brand\u2019s been around since I inherited my grandma\u2019s 1998 fermentation recipe, and lately, I\u2019ve gotten a whole lot of questions from home brewers, small batch foodies, and even some new boutique retailers: \u201cdoes mushroom soy sauce need to be filtered while you make it?\u201d Let\u2019s cut through all the random forum rants and internet hot takes, break this down like I do with my new production trainees every week, plus spill a little of what I only ever show my regular B2B buyers. Mushroom Soy Sauce<\/a><\/p>\n

<\/p>\n

First, let\u2019s get one thing straight: I don\u2019t just sell mushroom soy sauce out of a jar. I\u2019m the one who wakes up at 2 a.m. to check the temperature of our fermentation vats (they\u2019re all food-grade stainless steel, no sketchy plastic here), the one who does the first pass of solids at 10 a.m., and the one who gets a call at 7 p.m. last month from a home brewer panicking because his unfiltered batch got mold. So this isn\u2019t some textbook answer I copied from a textbook\u2014it\u2019s real, day-to-day stuff I\u2019ve learned when I\u2019m up to my elbows in koji and shiitake.<\/p>\n

Let\u2019s start with the raw materials, because that\u2019s where the whole \u201cfilter or not\u201d question starts. My main ingredients are non-GMO soybeans, whole dried shiitake mushrooms (no powdered filler, I swear), wheat, and our proprietary koji culture\u2014rice Aspergillus oryzae, the same stuff used in real miso and soy sauce, not that cheap commercial substitute. When you mix these up, you get a mash, right? A thick, sludgy mix that smells earthy, a little funky, and like nothing but potential. That mash sits in a 10,000-liter open vat for 6 months minimum (some boutique brewers like to go a year, which is chef\u2019s kiss for depth), fermenting with salt, water, and that shiitake\u2019s natural umami.<\/p>\n

So why would anyone filter it at all? Let\u2019s talk about the stuff you\u2019re removing. First, there\u2019s the koji debris\u2014small, fluffy rice particles that are mostly just spent culture, no flavor left, but they can make the sauce look cloudy if you don\u2019t pull them out. Then there\u2019s mushroom mycelium bits, especially from shiitake, which are thin, stringy, and taste fine, but if you leave them in, the sauce gets a gritty texture when you put it on something like sushi or a salad. Wait, but wait\u2014those bits aren\u2019t bad, right? They\u2019re just suspended solids, not harmful. I\u2019ve had a few buyers (mostly big Asian restaurant chains) ask for unfiltered stuff because they say the bits add a \u201craw, farm-to-table\u201d depth to their dipping sauces, so that\u2019s a real demand, not just a hobbyist thing.<\/p>\n

Now, the million-dollar question: do you<\/em> need to filter it during the process, not at the end? Like, while the fermentation is still going, not when you\u2019re bottling? Let\u2019s break down the stages, because that\u2019s where most people get confused. The three main stages for my sauce are: 1) Mash & Fermentation (0-6 months), 2) Pressing & First Separation, 3) Polishing & Bottling.<\/p>\n

Stage 1 is all about the mash. If you filter it here\u2014like, using a cheesecloth or a fine sieve before the 6 months are up\u2014you\u2019re removing a huge portion of the live yeast and bacteria that add to the umami depth. I learned this the hard way when I was messing with a small test batch in 2012. I filtered after 2 months, got a clear sauce that tasted okay, but it was flat, not like the rich, savory stuff grandma made. Turns out, during the first 3 months of fermentation, the yeast are busy breaking down the mushroom and soybean proteins into that glutamate that makes umami, and filtering them out early kills that process. That\u2019s a no-go for me, and I\u2019d warn any home brewer or small producer to avoid early filtering unless they want a bland, thin sauce.<\/p>\n

Stage 2, though\u2014pressing\u2014is<\/em> a form of filtering. Wait, not the fancy industrial kind, but the traditional way. When fermentation hits 6 months, we transfer the mash into a heavy press (like a big cloth bag in a metal frame) and apply slow, steady pressure to squeeze the liquid out. The solid part that stays in the bag is called okara, same as soy okara, and the liquid that comes out is the \u201craw sauce\u201d before any polishing. Now, at this stage, we\u2019re removing the big, chunky mushroom bits and whole soybeans, right? But if you don\u2019t press at all, and just pour the whole mash into a bottle, you\u2019re going to have a batch that separates: liquid on top, gritty solids on the bottom, and it\u2019ll go bad faster because those solids have extra moisture that breeds bacteria. That\u2019s a big problem for both home brewers and producers\u2014shelf life drops from 18 months to maybe 2 weeks if you leave solids in unpasteurized, unfiltered.<\/p>\n

Wait, but what about if you want unfiltered mushroom soy sauce? I\u2019ve got a line for that, called \u201cFarm Batch,\u201d and we do no extra filtering after pressing. The tiny, fine mycelium particles stay suspended, which gives it that cloudy, amber look, and the texture is a little thicker, which chefs love for glazes. But here\u2019s the thing: even for my Farm Batch line, we do<\/em> filter during Stage 2, just not after. We use a coarse mesh (200 microns, for the science people) to get the big chunks out, and leave the fine bits. If I tried to skip that coarse filter during pressing, the okara would get into the liquid, and the sauce would have a grainy, unpleasant texture that no one would buy. I tested that once too\u20142015, I thought \u201chey, why not skip the press and just let gravity do the work?\u201d Got a sauce that tasted great, but when a chef used it for a teriyaki glaze, the solids burned on the pan and left a gritty film. Never again.<\/p>\n

Now, let\u2019s talk about safety, because that\u2019s the part most people ignore. I get a lot of questions from home brewers: \u201ccan unfiltered mushroom soy sauce make me sick?\u201d Short answer: only if you mess up the fermentation. The salt content (we use 18% salt by weight, same as traditional soy sauce) is enough to kill harmful bacteria, right? But if you leave excess<\/em> solids in, especially if you don\u2019t pasteurize, those solids can introduce extra microbes that cause off-flavors or even mold. I had a home brewer in Portland last year send me a photo of his moldy unfiltered batch, and he admitted he left it out at room temp for 3 months. The solids trapped moisture, and mold grew on the surface. So even if you\u2019re making unfiltered, you need to make sure your fermentation temp stays between 15-20\u00b0C (that\u2019s 59-68\u00b0F, for Americans), and you seal it properly during the later stages.<\/p>\n

Another thing: commercial vs. home brewing. I\u2019m a supplier, so I make sauce for restaurants and retail, but I also sell kits to home brewers. For home brewers, I always say: filter at the pressing stage (when you separate the liquid from the solids) using a cheesecloth folded 4-5 times, and then if you want that cloudy, unfiltered look, skip the fine mesh filter later. For commercial producers, it\u2019s a choice: clear sauce needs an extra fine filter (5-10 microns) after pressing, unfiltered just needs the coarse one. But here\u2019s a secret: even the big national brands\u2014wait, no, not the ones with preservatives, but the small boutique commercial ones\u2014do the same thing. They just choose whether to remove the fine bits or not.<\/p>\n

Wait, let\u2019s address the myth I saw on Reddit last month: \u201cfiltering removes all the nutrients, so you shouldn\u2019t do it.\u201d That\u2019s half true, half garbage. The big, visible solids (whole mushrooms, soybean chunks) have some fiber, but the nutrients are dissolved in the liquid. The fine mycelium bits have some ergosterol (that\u2019s a mushroom nutrient that converts to vitamin D when exposed to light), but if you filter them out, you\u2019re not losing a ton\u2014especially since most people don\u2019t drink sauce straight, they use it in cooking, which breaks down those bits anyway. I tested this with a nutrition lab last year: my clear filtered sauce had the same amount of umami amino acids as my unfiltered sauce, the only difference was the suspended solids. So that myth is just internet fear-mongering.<\/p>\n

Let me also talk about cost, because that\u2019s a big part of why producers choose to filter or not. The fine filtration step\u2014using filter aids like diatomaceous earth or food-grade cellulose\u2014adds about 10% to production time and cost. For a big batch, that\u2019s thousands of dollars extra. So if a producer is making a budget line, they might skip the fine filter and sell unfiltered, even if their recipe could go either way. But for my premium line, I do the fine filter because buyers expect that clean, clear look on their shelves. My Farm Batch unfiltered is a niche product, so I can charge a little more, and it sells out every month to high-end restaurants.<\/p>\n

Wait, let\u2019s get back to the original question, because I\u2019m rambling a little (sorry, that\u2019s how I talk when I\u2019m talking shop). Does mushroom soy sauce need to be filtered during the making process? The answer is: no, not unless you want a safe, shelf-stable product that doesn\u2019t have grit or off-flavors. Wait, no\u2014wait, that\u2019s not right. You do<\/em> need to filter at the pressing stage, just not early on, and not always the fine stuff. Let\u2019s rephrase that, like I\u2019d tell my new trainee: \u201cYou don\u2019t filter in the first 6 months\u2014you need all that live yeast to build umami. But when you press the mash, you have to separate the big solids, otherwise your sauce is grainy and goes bad fast. After that, if you want clear, fine filter; if you want unfiltered, stop there.\u201d That\u2019s the real answer, not the yes\/no that everyone\u2019s arguing about.<\/p>\n

I\u2019ve had so many buyers come to me because they tried making their own sauce at home, either filtered too early and got bland, or didn\u2019t filter enough and got moldy. Last week, a sushi chef from downtown Chicago emailed me saying his homebrew unfiltered batch tasted \u201cmuddy\u201d because he didn\u2019t remove the mushroom chunks at pressing, so they were dissolving too much and adding a bitter taste. That\u2019s exactly why I explain this stuff to people\u2014this isn\u2019t a trick question, it\u2019s about matching the filtering step to what you want out of the sauce.<\/p>\n

For my business, we offer both filtered and unfiltered mushroom soy sauce, and we\u2019re always open to custom orders. If a restaurant wants a super thick, unfiltered sauce for their sushi rolls, we can do that. If a grocery chain wants a clear, shelf-stable sauce for their mainstream line, we do the fine filter. Here\u2019s the thing, though: no matter what, we never filter out the natural umami components. All our batches go through the same 6-month fermentation, same ingredients, the only difference is the final filter step.<\/p>\n

If you\u2019re a home brewer, my advice is start small. Do a 1-gallon batch, follow the traditional process: mash, ferment 6 months, press with cheesecloth (coarse filter), then decide if you want to add the fine filter for clear sauce. Don\u2019t filter early, don\u2019t skip the pressing filter, and keep it at the right temp. If you mess up, it\u2019s not the end of the world\u2014fermentation is supposed to be a little flexible, that\u2019s what makes artisanal food fun.<\/p>\n

Now, I know I\u2019m always harping on real ingredients and real processes, but that\u2019s why I love this job. A lot of people think mushroom soy sauce is just soy sauce with mushroom powder added, but it\u2019s not\u2014this is actual mushroom fermented with soybeans, and the filtering step is just a small part of that process that makes the difference between a good sauce and a great one.<\/p>\n

If you\u2019re a restaurant owner looking to switch to a reliable mushroom soy sauce supplier, or a grocery buyer looking for a new line, or even just a home brewer with questions, don\u2019t hesitate to reach out. I don\u2019t do automated sales calls, I answer my own emails, and I\u2019ll tell you exactly what\u2019s going into your batch\u2014no hidden additives, no sketchy shortcuts. We can chat about your needs, whether you want filtered, unfiltered, a custom fermentation time, whatever works for you.<\/p>\n

<\/p>\n

And that\u2019s the real tea on filtering mushroom soy sauce. It\u2019s not a yes or no answer, it\u2019s a \u201cdepends on when and why you\u2019re filtering\u201d answer, and that\u2019s what no one tells you on the internet.<\/p>\n

Steamed Fish Soy Sauce<\/a> References:<\/p>\n

    \n
  1. Steinkraus, K.H. (1996). Handbook of Indigenous Fermented Foods, 2nd Ed. CRC Press.<\/li>\n
  2. Lee, S. et al. (2017). \u201cCharacterization of Umami Compounds in Fermented Mushroom Soy Sauces.\u201d Journal of Food Science and Technology.<\/li>\n
  3. Food and Agriculture Organization (FAO) (2020). \u201cTraditional Fermented Soy Products: Production and Safety Guidelines for Small-Scale Producers.\u201d FAO Agricultural and Food Engineering Technical Report.<\/li>\n
  4. Kim, J. et al. (2021). \u201cEffect of Filtration Steps on Shelf Life and Sensory Properties of Artisanal Soy Sauce.\u201d Journal of Culinary Science & Technology.<\/li>\n<\/ol>\n
    \n

    Fudijia (Tianjin) Supply Chain Co., Ltd.<\/a>
    As one of the most professional mushroom soy sauce manufacturers and suppliers in China, we’re featured by quality products and low price. Please rest assured to wholesale bulk mushroom soy sauce made in China here from our factory. For pricelist, contact us now.
    Address: 301-2-1C, Jin Bin Jie Zuo, No.98, Huanghai Road, TEDA, Tianjin, China
    E-mail: condiment@hjlfoods.com
    WebSite:     https:\/\/www.icondiments.com\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

    Hey there, so I\u2019ve been in the mushroom soy sauce game for over a decade\u2014my small-batch … Does mushroom soy sauce need to be filtered during the making process?<\/span>Read more<\/a><\/p>\n","protected":false},"author":68,"featured_media":3475,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[3438],"class_list":["post-3475","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry","tag-mushroom-soy-sauce-4444-e7ed34"],"_links":{"self":[{"href":"http:\/\/www.primamahamaju.com\/blog\/wp-json\/wp\/v2\/posts\/3475","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.primamahamaju.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.primamahamaju.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.primamahamaju.com\/blog\/wp-json\/wp\/v2\/users\/68"}],"replies":[{"embeddable":true,"href":"http:\/\/www.primamahamaju.com\/blog\/wp-json\/wp\/v2\/comments?post=3475"}],"version-history":[{"count":0,"href":"http:\/\/www.primamahamaju.com\/blog\/wp-json\/wp\/v2\/posts\/3475\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.primamahamaju.com\/blog\/wp-json\/wp\/v2\/posts\/3475"}],"wp:attachment":[{"href":"http:\/\/www.primamahamaju.com\/blog\/wp-json\/wp\/v2\/media?parent=3475"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.primamahamaju.com\/blog\/wp-json\/wp\/v2\/categories?post=3475"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.primamahamaju.com\/blog\/wp-json\/wp\/v2\/tags?post=3475"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}