{"title":"Mushroom Grain Substrate","description":"\u003ch2\u003e\u003cstrong data-path-to-node=\"4\" data-index-in-node=\"0\"\u003eQuality Grain Substrates - The Foundation of Every Flush.\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eWhether you are embarking on the journey of preparing sterile grain spawn or skillfully mixing your own bulk fruiting blocks, it's essential to remember that the quality of your raw materials plays a crucial role in determining both the speed and health of your grow.\u003c\/p\u003e\n\u003cp\u003eThat’s why we are proud to introduce our exclusive Grain \u0026amp; Substrates collection, crafted with the exact same high-quality ingredients that we utilize at Kai Kai Farm. From our carefully selected high-hydration grains to our premium hardwood amendments, you can trust that these professional-grade inputs will empower you in transforming mycelium into bountiful mushrooms. Elevate your growing experience and enjoy the fruits of your labor with our dependable, top-notch products!\u003c\/p\u003e","products":[{"product_id":"chalk-calcium-carbonate-mushroom-supplement","title":"Calcium Carbonate (Chalk) Mushroom Supplement","description":"\u003cp\u003eCalcium Carbonate — commonly known as chalk — is one of the most reliable and widely used supplements in mushroom cultivation. Its primary role is as a pH buffer: as mycelium colonises a substrate, it produces acids that can gradually push the pH into a range that inhibits growth or invites contamination. A small addition of calcium carbonate keeps the environment stable, giving your mycelium the consistent conditions it needs to colonise fully and fruit well.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003eWhat it does in your substrate\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eBuffers pH:\u003c\/strong\u003e counteracts the natural acidification that occurs during colonisation, maintaining a more stable and mycelium-friendly environment throughout the grow.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAdds calcium:\u003c\/strong\u003e calcium is an essential mineral for fungal cell wall development and helps mycelium grow stronger, denser, and more resilient.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eReduces contamination risk:\u003c\/strong\u003e a stable, slightly alkaline substrate is a less welcoming environment for many competing moulds and bacteria, helping your mycelium get established before contaminants can take hold.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003eWhere to use it\u003c\/h3\u003e\n\n\u003cp\u003eCalcium carbonate is suitable for sterilised and pasteurised bulk substrates, casing mixes, and grain spawn. It's particularly useful in supplemented hardwood substrates (Masters Mix and similar) where higher nitrogen content can accelerate acidification. Recommended at \u003cstrong\u003e0.5–1% by dry weight\u003c\/strong\u003e of your substrate mix.\u003c\/p\u003e\n\n\u003cp\u003eIt's also excellent in garden applications — a gentle, slow-release source of calcium for vegetable beds, raised planters, and pots where pH drift is a concern.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003eAvailable sizes\u003c\/h3\u003e\n\n\u003cp\u003eAvailable in 100g, 250g, 500g, and 1KG bags — scaled for hobbyist to small commercial grows. Sourced and packed in Australia.\u003c\/p\u003e","brand":"Kai Kai Farm","offers":[{"title":"100g","offer_id":51644292399415,"sku":"MS-CLK-10","price":5.0,"currency_code":"AUD","in_stock":true},{"title":"250g","offer_id":50680002314551,"sku":"MS-CLK-25","price":7.0,"currency_code":"AUD","in_stock":true},{"title":"500g","offer_id":50680002347319,"sku":"MS-CLK-50","price":9.0,"currency_code":"AUD","in_stock":true},{"title":"1KG","offer_id":50680002380087,"sku":"MS-CLK-1KG","price":12.0,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0791\/2040\/0695\/files\/Chalk_Calcium_Carbonate_Mushroom_SupplementpHBooster.webp?v=1761892706"},{"product_id":"gypsum-calcium-sulfate-fine-grade-for-grain-substrate","title":"Gypsum Fine Grade | Grain Spawn Substrate Supplementation","description":"\u003ch2 class=\"p3\"\u003e\u003cspan class=\"s2\"\u003e\u003cstrong\u003eEnhance your cultivation success with our high-purity Fine Grade Gypsum\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp class=\"p3\"\u003e\u003cspan class=\"s2\"\u003e\u003cstrong\u003eSsourced from food-grade mineral additive essential for both mushroom growers and soil enthusiasts. This fine-grade calcium sulphate is a staple in the mycology world, trusted by cultivators to improve the quality of grain spawn and promote robust mycelial health from the very first stage of growth.\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003ch2 class=\"p3\"\u003e\u003cspan class=\"s2\"\u003e\u003cstrong\u003eThe Mycology Essential: Why Use Gypsum?\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp class=\"p3\"\u003e\u003cspan class=\"s2\"\u003e\u003cstrong\u003eIn mushroom cultivation, the physical structure of your substrate is just as important as its nutrient content. Our Gypsum is ultra-fine and food-safe, making it perfect for evenly coating and mixing through hydrated grain prior to sterilisation. One of its primary roles is acting as an anti-clumping agent; it keeps individual grains separate, which significantly increases the number of inoculation points and allows for faster, more even colonisation. Beyond texture, Gypsum provides essential calcium and sulphur—two key nutrients that act as building blocks for vigorous mycelium growth and help stabilise the pH levels of your substrate.\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003ch2 class=\"p3\"\u003e\u003cspan class=\"s2\"\u003e\u003cstrong\u003eBenefits for Soil and Garden Health\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp class=\"p3\"\u003e\u003cspan class=\"s2\"\u003e\u003cstrong\u003eWhile it is a \"must-have\" for the lab, Gypsum is equally valuable in the garden. It is a fantastic soil conditioner that helps break up heavy clay soils without altering the pH as dramatically as lime. By adding this mineral to your garden beds, you improve water penetration and aeration, creating an environment where roots—and beneficial soil microbes—can truly thrive.\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003ch2 class=\"p3\"\u003e\u003cspan class=\"s2\"\u003e\u003cstrong\u003eQuality You Can Trust\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp class=\"p3\"\u003e\u003cspan class=\"s2\"\u003e\u003cstrong\u003eWhether you are prepping jars for a gourmet grow or amending your backyard soil, our Gypsum offers a clean, reliable, and natural solution. It integrates seamlessly into any growing medium, ensuring your fungi and plants have access to the minerals they need for high-yield harvests and long-term vitality.\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"Kai Kai Farm","offers":[{"title":"100g","offer_id":51644333818167,"sku":"MS-GYPF-10","price":8.0,"currency_code":"AUD","in_stock":true},{"title":"250g","offer_id":50791780122935,"sku":"MS-GYPF-25","price":11.0,"currency_code":"AUD","in_stock":true},{"title":"500g","offer_id":50791780155703,"sku":"MS-GYPF-50","price":16.0,"currency_code":"AUD","in_stock":true},{"title":"1KG","offer_id":50791780188471,"sku":"MS-GYPF-1KG","price":23.0,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0791\/2040\/0695\/files\/GypsumFineGrade_CalciumSulphate_MushroomSupplement.webp?v=1751675465"},{"product_id":"organic-rye-grain","title":"Organic Rye Berries for Mushroom Grain Spawn — Bulk Pricing Available","description":"\u003cp\u003e\u003cstrong\u003eRaw unsterilised grain — ready to hydrate, sterilise and inoculate at home.\u003c\/strong\u003e This is bulk raw rye berries for growers who prepare their own grain spawn. If you're looking for ready-to-use sterilised substrate, see our \u003ca href=\"\/products\/all-in-one-mushroom-substrate-bags-1-4kg-finish-weight\"\u003eAll-in-One Substrate Bags\u003c\/a\u003e instead.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003cp\u003eIf there's a gold standard grain in mushroom cultivation, it's rye. Used for decades by hobbyists and commercial growers alike, organic rye berries offer a moisture absorption capacity, nutrient profile, and texture that few grains match. They hold water without bursting, provide consistent inoculation points throughout a jar or bag, and break and shake cleanly — reducing colonisation lag and keeping contamination risk low.\u003c\/p\u003e\n\n\u003cp\u003eAt $8.50\/kg raw, you're paying significantly less than pre-sterilised rye bags on the Australian market — with full control over your sterilisation process. Add multiple kilograms to cart for automatic bulk pricing at checkout.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003eWhy rye berries are the mycologist's grain of choice\u003c\/h3\u003e\n\n\u003cp\u003eRye's structure is what sets it apart. Each berry can absorb nearly its own weight in water without the husk splitting — meaning you get consistently hydrated grain that holds moisture through a full sterilisation cycle and keeps mycelium fed throughout colonisation. The nitrogen, phosphorus, and potassium profile is well-matched to what aggressive mycelium needs: you get vigorous, dense white growth rather than the pale, slow coverage that comes from nutritionally thin grains.\u003c\/p\u003e\n\n\u003cp\u003eBecause organic rye is free from the fungicides and pesticides common in feed-grade grain, there's no chemical residue to inhibit sensitive fungal strains. This matters more than many new growers realise — agricultural rye treated with fungicide is one of the most common silent causes of failed inoculations.\u003c\/p\u003e\n\n\u003ch3\u003eBest suited to\u003c\/h3\u003e\n\n\u003cp\u003eAll gourmet and medicinal species. Rye is particularly well-suited to more demanding species — Shiitake, King Oyster (Shimeji), Chestnut, and Reishi — where a nutrient-dense grain produces the best colonisation rates. It's equally effective for oyster varieties, Lion's Mane, and Pioppino. If you're working with a wide range of species and want one grain that performs reliably across all of them, rye is it.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003ePreparing your grain\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eHydration:\u003c\/strong\u003e Rinse well, then simmer in water for 15–20 minutes until berries have absorbed moisture and are just tender — firm with a slight give, not mushy. Drain, then spread on a clean surface to surface-dry for 30–60 minutes until no visible moisture remains on the grain. Over-hydrated rye is the leading cause of contamination in home sterilisation — drier is safer.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eSterilisation:\u003c\/strong\u003e Load into mason jars or filter-patch spawn bags, leaving 20–30% headspace. Sterilise at 15 PSI (121°C) for a minimum of 90–120 minutes. Allow pressure to drop naturally. Cool completely — ideally overnight — before inoculating.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eSpawn rate:\u003c\/strong\u003e 10–20% by weight into your bulk substrate. 1KG of finished grain spawn will inoculate approximately 5–10KG of bulk substrate depending on species and substrate composition. For sterilised hardwood or Masters Mix, the higher end of the range is recommended for faster colonisation.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003eThe Kai Kai Farm difference\u003c\/h3\u003e\n\n\u003cp\u003e100% organic, food-grade rye berries — no fungicide residues, no agricultural chemicals. The same grain standard we apply to everything that goes into our growing operation. Packed on our Tamborine Mountain farm. Add multiple kilograms to cart to access bulk pricing automatically at checkout.\u003c\/p\u003e","brand":"Kai Kai Farm","offers":[{"title":"Default Title","offer_id":51681172914487,"sku":"MS-RYE-1KG","price":8.5,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0791\/2040\/0695\/files\/OrganicRyeGrainForMushroomSubstrate.webp?v=1770952260"},{"product_id":"organic-wheat-grain-1kg","title":"Organic Wheat Grain for Mushroom Substrate — Bulk Pricing Available","description":"\u003cp\u003e\u003cstrong\u003eRaw unsterilised grain — ready to hydrate, sterilise and inoculate at home.\u003c\/strong\u003e This is bulk raw wheat grain for growers who prepare their own grain spawn. If you're looking for ready-to-use sterilised substrate, see our \u003ca href=\"\/products\/all-in-one-mushroom-substrate-bags-1-4kg-finish-weight\"\u003eAll-in-One Substrate Bags\u003c\/a\u003e instead.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003cp\u003eWhen you need the performance of a premium grain substrate without the price tag of rye, organic wheat grain is the answer. High in starch, with excellent moisture retention and a solid nitrogen profile, wheat berries produce fast, vigorous colonisation — making them a practical choice for both beginner growers and established operations running high volumes of substrate.\u003c\/p\u003e\n\n\u003cp\u003eAt $8.50\/kg raw, wheat costs a fraction of pre-sterilised bags on the Australian market — and at bulk quantities, the economics improve further. Add multiple kilograms to cart for automatic bulk pricing at checkout.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003eWhy wheat grain belongs in your rotation\u003c\/h3\u003e\n\n\u003cp\u003eWheat grain occupies the sweet spot between millet and rye. It provides a higher inoculation point density than rye (more, smaller grains per kilogram) while offering a more substantial nutrient base than millet. The starch content is high — an explosive energy source for mycelium that often produces faster run times than rye on equivalent substrates.\u003c\/p\u003e\n\n\u003cp\u003eOrganic wheat is also the most cost-effective high-quality grain option in the range. For growers running large volumes of oyster, Lion's Mane, or Shiitake cultivation — where substrate costs need to stay controlled — wheat is the grain that makes the economics work without compromising colonisation quality.\u003c\/p\u003e\n\n\u003cp\u003eAs with all our grain, this wheat is 100% organic and free from the fungicides commonly applied to agricultural feed grain. Fungicide-treated grain is a well-documented cause of failed inoculations — it's a risk that simply doesn't exist with food-grade organic wheat.\u003c\/p\u003e\n\n\u003ch3\u003eBest suited to\u003c\/h3\u003e\n\n\u003cp\u003eExcellent across the full range of gourmet species — oysters of all varieties, Lion's Mane, Shiitake, and Pioppino. Particularly well-suited to high-volume grows where cost control matters: oyster production at scale benefits significantly from wheat's combination of fast colonisation and lower per-kilogram cost versus rye. Also an excellent choice for Masters Mix supplemented hardwood grows.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003ePreparing your grain\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eHydration:\u003c\/strong\u003e Rinse thoroughly, then simmer in water for 15–20 minutes until berries are fully hydrated and tender — the grain should swell visibly, remain intact, and show no hard white core when cut. Drain well, then surface-dry on a clean tray for 30–60 minutes. Like rye, over-hydrated wheat is a contamination risk — aim for field capacity: no surface moisture, a dull surface rather than shiny.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eSterilisation:\u003c\/strong\u003e Load into mason jars or filter-patch spawn bags, leaving 20–30% headspace. Sterilise at 15 PSI (121°C) for a minimum of 90–120 minutes. Allow pressure to drop naturally before opening. Cool completely before inoculating.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eSpawn rate:\u003c\/strong\u003e 10–20% by weight into your bulk substrate. 1KG of finished grain spawn will inoculate approximately 5–10KG of bulk substrate depending on species and substrate type. Wheat works particularly well in supplemented hardwood substrates where its high starch provides a complementary nutrient profile.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003eThe Kai Kai Farm difference\u003c\/h3\u003e\n\n\u003cp\u003e100% organic, food-grade wheat — the same standard we apply to every input across our own commercial production. No fungicide residues, no feed-grade agricultural chemicals. Clean, reliable grain for clean, reliable results. Packed on our Tamborine Mountain farm. Add multiple kilograms to cart to access bulk pricing automatically at checkout.\u003c\/p\u003e","brand":"Kai Kai Farm","offers":[{"title":"Default Title","offer_id":51681285996855,"sku":"MS-WHE-1KG","price":8.5,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0791\/2040\/0695\/files\/OrganicWheatGrainForMushroomSubstrate.webp?v=1770957956"},{"product_id":"millet-grain-1kg","title":"Unhulled Millet Grain for Mushroom Spawn — Bulk Pricing Available","description":"\u003cp\u003e\u003cstrong\u003eRaw unsterilised grain — ready to hydrate, sterilise and inoculate at home.\u003c\/strong\u003e This is bulk raw millet for growers who prepare their own grain spawn. If you're looking for ready-to-use sterilised substrate, see our \u003ca href=\"\/products\/all-in-one-mushroom-substrate-bags-1-4kg-finish-weight\"\u003eAll-in-One Substrate Bags\u003c\/a\u003e instead.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003cp\u003eFor the grower who sterilises their own grain, millet is the logical starting point. White French Millet has more individual grains per kilogram than any other substrate grain — meaning more inoculation points, faster initial colonisation, and a more even spread of mycelium through your bulk substrate from the first break and shake.\u003c\/p\u003e\n\n\u003cp\u003eAt $4\/kg raw, you're paying a fraction of the cost of pre-sterilised bags — without sacrificing quality. Sterilise it yourself and you control the moisture content, sterilisation time, and final grain weight. Add multiple kilograms to cart for automatic bulk pricing.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003eWhy millet works so well\u003c\/h3\u003e\n\n\u003cp\u003eThe numbers tell the story: rye grain yields roughly 2,000–3,000 kernels per kilogram; white millet yields closer to 100,000–120,000. More kernels means more contact points when you introduce your culture, faster spread when you break and shake, and significantly less lag time between inoculation and full colonisation. That speed advantage compounds across every batch.\u003c\/p\u003e\n\n\u003cp\u003eThe thin, delicate hull on unhulled millet also allows mycelium to penetrate the starch rapidly — you'll see aggressive white growth within days of a clean inoculation. It shakes out easily, clumps less than rye, and transfers cleanly in grain-to-grain (G2G) work, making it the preferred carrier grain for master jar expansion.\u003c\/p\u003e\n\n\u003ch3\u003eBest suited to\u003c\/h3\u003e\n\n\u003cp\u003eOyster mushrooms of all varieties, Lion's Mane, Pioppino, Reishi, and most gourmet species. Millet is particularly effective for G2G expansion work — the ideal carrier grain for moving a healthy culture from a master jar into bulk bags before adding to substrate. Also the preferred grain for PF Tek-adjacent techniques where small jar sizes call for maximum inoculation density.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003ePreparing your grain\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eHydration:\u003c\/strong\u003e Rinse thoroughly, then simmer in water for 10–12 minutes until the outer hull softens but kernels remain intact. Don't overcook — burst grains invite contamination. Drain well, then surface-dry on a clean tray until no visible moisture remains. Target: field capacity. No drips, a slight sheen.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eSterilisation:\u003c\/strong\u003e Load into jars or spawn bags, leaving 20–30% headspace. Sterilise at 15 PSI (121°C) for a minimum of 90 minutes. Allow pressure to drop naturally before moving. Cool completely before inoculating — never work with warm grain.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eSpawn rate:\u003c\/strong\u003e 10–20% by weight into your bulk substrate. 1KG of finished grain spawn will inoculate approximately 5–10KG of bulk substrate, depending on substrate composition and species.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003eThe Kai Kai Farm difference\u003c\/h3\u003e\n\n\u003cp\u003eThis is the same White French Millet we use across our own commercial production — selected for hull integrity, consistent moisture absorption, and low contaminant risk. Sourced and packed on our Tamborine Mountain farm. Add multiple kilograms to cart to access bulk pricing automatically at checkout.\u003c\/p\u003e","brand":"Kai Kai Farm","offers":[{"title":"Default Title","offer_id":51681290617143,"sku":"MS-MIL-1KG","price":4.0,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0791\/2040\/0695\/files\/Unhulled_Millet_For_Mushroom_Grain_Substrate.webp?v=1771996618"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0791\/2040\/0695\/collections\/Grain_Substrate_800x800_74e4538f-416d-45fd-9253-6287f640acde.jpg?v=1771997416","url":"https:\/\/kaikaifarm.au\/collections\/mushroom-grain-substrates.oembed","provider":"Kai Kai Farm","version":"1.0","type":"link"}