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Which Classic Jar Kit Is Right for You?
All three kits use the same PF Tek growing method and the same in-house BRF jar formulation. The differences come down to chamber size, automation, jar count, and what kind of grow space you have available.
Mega Kit — Our Flagship
Best for: Most growers. The biggest harvest, the most jars, and the most automation in our classic kit lineup.
The Mega Kit is the largest classic jar grow kit we make. It includes:
- 18 sterilized BRF jars (half-pint)
- 56-quart fruiting chamber (22 x 16 x 11 inches)
- Hydroponic humidifier for humidity control (no need to drill hundreds of holes for the shotgun fruiting chamber method)
- 50W heat mat for incubation temperature
- Built-in filter for clean air exchange
- Complete instructions plus access to our 8-part video grow guide after checkout
This is what we recommend for almost everyone buying their first classic jar kit. More jars, bigger chamber, and the humidifier eliminates the most tedious DIY step of traditional PF Tek.
Ultimate Kit — For Cold Climates
Best for: Growers in cold basements, garages, or unheated spaces where ambient temperature drops below 65°F.
The Ultimate Kit is built around a water-bath heating system that solves the biggest problem in cold-climate cultivation: keeping the substrate warm enough to colonize properly. The kit uses an aquarium heater submerged in water between two nested tubs — the heat transfers up through the water bath into the fruiting chamber, raising the internal temperature 20°F or more above ambient when needed.
- 12 sterilized BRF jars (half-pint)
- 30-quart fruiting chamber (18 x 10 x 12 inches)
- 50W aquarium heater with water-bath heating system (two nested tubs)
- Perlite-based humidity — no humidifier needed; the perlite emits enough moisture and the air pump tube goes directly into the perlite layer on a timer for fresh air exchange
- Built-in filter for clean air exchange
- Complete instructions plus access to our 8-part video grow guide after checkout
The Ultimate is the kit for anyone whose grow space is too cold for a heat mat to handle. Smaller chamber, fewer jars, but the temperature control is in a different league.
Simple Mushroom Grow Kit Plus — Entry Level
Best for: First-time growers, budget-conscious buyers, or anyone who wants a complete PF Tek setup without automation.
The Simple Kit Plus is a manual setup built on one of our smaller monotubs. No heating element, no humidifier, no fresh air pump — you handle temperature and air exchange yourself. Includes:
- 6 sterilized BRF jars (half-pint)
- Small monotub fruiting chamber
- Perlite for humidity
- LED grow light
- Thermometer/hygrometer
- Vermiculite for dunk and roll
- Complete instructions plus access to our 8-part video grow guide after checkout
Why PF Tek still matters in 2026
Over the past decade, mushroom cultivation content online has shifted heavily toward bulk growing methods — monotubs, all-in-one bags, and grain-to-bulk workflows. PF Tek has been quietly dismissed as outdated. We disagree, and 15 years of customer grows back us up. Here is why PF Tek is still the best method for beginners, and why we still build these kits.
- Built-in redundancy. A Mega Kit gives you 18 separate jars. If one or two get contaminated, you still have 16 successful grows. Compare that to a single all-in-one bag or monotub: one contamination event and the entire grow is lost.
- The fastest path to your first mushroom. PF Tek is genuinely the quickest method from inoculation to harvest. We routinely see customers with pins in under 30 days of injecting their jars. No bulk growing method can match that timeline. A standard grain-to-bulk monotub takes 5 to 8 weeks before you see your first flush.
- Real yields, not just learning experiences. A Mega Kit running well can produce 5 to 6 dry ounces of mushrooms across multiple flushes. Each jar typically produces 3 flushes, with the cake being dunked and rolled between each flush to rehydrate. That is a real harvest, not a token amount.
- Lower contamination stakes per failure. If a beginner messes up their inoculation technique on a monotub or all-in-one bag, they lose the entire grow. If a beginner messes up one jar in a PF Tek kit, they lose one jar. The learning curve is significantly less punishing.
- No flow hood, no sterile lab required. The small jar opening and quick inoculation through the lid is sanitary enough for clean home grows. Bulk methods are more forgiving once you know what you are doing but require more sterile technique upfront.
PF Tek is not the highest-yield method per square foot — that title belongs to monotubs. But for first-time growers, for anyone in a small space, or for anyone who wants to minimize the cost of a single contamination event, the classic jar method is still the smartest place to start.
Why our BRF jars are different
Most PF Tek kits use a simple brown rice flour, vermiculite, and water formulation. Our jars include one additional ingredient that makes a noticeable difference:
- Brown rice flour — the classic PF Tek nutritional base
- Vermiculite — for moisture retention and airflow through the substrate
- Water — hydrated to the exact ratio needed for clean colonization
- Liquid worm castings — a small amount added to support stronger, more vigorous mycelium growth
The worm castings are the secret. They add micronutrients that standard BRF jars lack, which translates to faster colonization, denser mycelial growth, and bigger flushes. Made fresh in-house at Midwest Grow Kits, sterilized in our autoclaves, and shipped ready to inoculate.
Quick decision tree
- Want the biggest harvest with the most automation? Mega Kit.
- Grow space is cold (basement, garage, anywhere under 65°F)? Ultimate Kit.
- First-time grower or want the simplest entry point? Simple Mushroom Grow Kit Plus.
- Already have a kit and just need jars? See our BRF / PF Tek Jar Refills.
Reusable design, refillable jars
Every classic jar kit we make is built to be reused indefinitely. The fruiting chamber, heating element, humidifier (Mega), water bath system (Ultimate), and air pump are all permanent equipment. The jars themselves are the consumable — you keep the glass and replace just the sterilized substrate. We sell BRF / PF Tek jar refills in case quantities so you can run grow after grow without buying another full kit.
Made in-house, since 2011
The Mega Kit and Ultimate Kit were Midwest Grow Kits' very first products when we opened in May 2011. Fifteen years later, they're still made in-house in our Illinois facility, refined and improved every year based on what we learn from our customers and our own grows. No outsourcing, no rebranding — the kit you receive is built by the same team that designed it.
Frequently Asked Questions About Classic Jar Grow Kits
What is PF Tek and why is it called that?
PF Tek (short for "Psilocybe Fanaticus Technique") is the classic home mushroom cultivation method developed in the 1990s by Robert McPherson. It uses half-pint mason jars filled with a brown rice flour and vermiculite substrate, sterilized in a pressure cooker, inoculated with a spore or culture syringe, and fruited inside a humid chamber. It is the method that introduced home mushroom cultivation to mainstream growers and remains the most accessible entry point to the hobby.
What is the difference between the Mega, Ultimate, and Simple kits?
The Mega is our flagship: 18 jars, a 56-quart chamber, a humidifier for humidity control, and a 50W heat mat for warmth. The Ultimate is built for cold climates: 12 jars, a 30-quart chamber, and an aquarium heater with a water-bath system that can raise internal temperature 20°F or more above ambient. The Simple Kit Plus is the entry-level option: 6 jars in a small monotub, with perlite for humidity but no automated heating or humidification. All three use the same BRF jar formulation.
Which kit should I choose if my grow space is cold?
The Ultimate Kit is the right choice. Its water-bath heating system using a 50W aquarium heater can raise the internal chamber temperature 20°F or more above ambient — meaning it works in basements, garages, or any unheated space where a standard heat mat (like the Mega uses) would struggle. We specifically recommend the Ultimate for anyone whose grow space drops below 65°F.
Why do your BRF jars include worm castings?
Standard PF Tek jars use only brown rice flour, vermiculite, and water. We add a small amount of liquid worm castings to provide micronutrients that pure BRF lacks. The result is stronger, more vigorous mycelium growth, faster colonization, and bigger flushes. It is a small change but makes a noticeable difference in performance compared to standard BRF jars.
How many flushes can I expect from a single jar, and what yields are realistic?
Each colonized BRF cake typically produces 3 flushes before it is exhausted. After each flush, dunk the cake in cold water and roll it in vermiculite to rehydrate before returning it to the fruiting chamber. Across a full grow, customers running a Mega Kit (18 jars) regularly harvest 5 to 6 dry ounces of mushrooms total. The Ultimate Kit (12 jars) produces proportionally less; the Simple Kit Plus (6 jars) produces around a third of the Mega's output. Yields drop with each subsequent flush.
How long does a classic jar grow take, start to finish?
PF Tek is the fastest method to your first harvest. Customers regularly see pins in under 30 days of inoculation, with full first flush around 5 to 6 weeks. Subsequent flushes come every 1 to 2 weeks after the first. Compare to bulk growing methods (monotubs, all-in-one bags), which typically take 5 to 8 weeks just to first flush.
Why is PF Tek still relevant when bulk methods produce bigger yields?
Three reasons. First, redundancy: a Mega Kit's 18 jars means one or two contamination events do not lose the entire grow. A single monotub or all-in-one bag has no such backup. Second, speed: PF Tek produces pins in under 30 days, faster than any bulk method. Third, learning curve: a beginner mistake on one jar loses one jar, while the same mistake on a monotub loses the whole grow. PF Tek is the smartest method for beginners, small spaces, and anyone who wants to minimize the cost of a single failure.
Do these kits include a spore or culture syringe?
No. We do not sell spore syringes, and the kits do not include them. You will need to source a spore syringe from a trusted vendor (see our 2026 Spore Syringe Buying Guide) or use one of our liquid culture syringes. LC syringes colonize faster and more reliably and are what we recommend for these kits.
Can I reuse these kits or do I need to buy a new one each time?
Every classic jar kit is fully reusable. The fruiting chamber, heating element, humidifier (Mega), water-bath system (Ultimate), and air pump are all permanent equipment. The BRF jars themselves are the consumable — keep the glass and buy refills. We sell BRF / PF Tek jar refills in case quantities for repeat grows.
What does the 8-part video grow guide cover?
After checkout, every customer gets emailed access to our complete 8-part instructional video series covering every step of the PF Tek growing process: inoculation, incubation, birthing the cake, the dunk and roll, fruiting conditions, harvesting, multiple flushes, and troubleshooting. These videos go into significantly more depth than the written instructions and have been refined over 15 years of customer feedback.
What temperature do I need to maintain during colonization?
Optimal colonization temperature is 70 to 80°F at the jar level. The Mega's heat mat handles this in most indoor spaces. The Ultimate's water-bath system handles this in cold spaces (basements, garages) where ambient temperature drops well below 70°F. The Simple Kit Plus has no heating element, so you'll need to keep your grow space at room temperature on your own.
Do I need a flow hood to use these kits?
No. The classic PF Tek method is designed to be done without a flow hood — the small jar opening and quick inoculation through the lid (or with a sanitized needle into the substrate) is sanitary enough for most home grows. A laminar flow hood reduces contamination risk further and is worth the investment if you scale up, but it is not required for these kits.
What's the difference between these kits and a monotub kit?
A classic jar kit uses the PF Tek method: small half-pint BRF jars colonized individually, then birthed into a fruiting chamber as cakes. A monotub kit uses bulk growing: colonized grain spawn mixed into bulk substrate inside a large filtered tub. Monotubs produce significantly larger yields per grow but require more substrate and a bigger setup. Classic jar kits are smaller, more affordable, redundant (multiple independent jars), and the traditional way most growers learned cultivation.