All in One Grow Bag vs Monotub: Which Method Actually Fits Your Grow?
A guy stood at my counter last spring holding a receipt for three all in one bags in one hand and a printed forum thread about monotub builds in the other, asking me to just tell him which one to buy. So here is the short answer, the one I gave him: the bag wins on simplicity and low contamination risk, while the monotub wins on yield, scalability, and long term cost per harvest. Neither method is universally better. The right choice depends on how much you want to produce, how much time you can put into substrate preparation and environment management, and where you are in your learning curve.
I have been selling both all in one grow bags and the supplies people use to build monotubs since 2009. I have also run both systems personally across dozens of gourmet species, on my own shelves before I would ever recommend them to someone else. What I see from customer questions and order patterns tells me a lot about where each method succeeds and where people run into trouble. This guide gives you the honest comparison.
Out-Grow Quick Answer
- All in one grow bags have fewer steps, lower contamination risk, and work well for small personal harvests or first grows.
- Monotubs require more substrate preparation and environmental management, but produce more mushrooms per batch and cost less per harvest over time.
- Fruiting conditions for most edible species land in the same range for both methods: 85 to 95% relative humidity and 15 to 27 degrees Celsius (60 to 80 degrees Fahrenheit), adjusted by species.
- Both methods work for legal gourmet and functional species including oyster, lion's mane, and shiitake, but substrate choices differ between them.
- Start with a bag if you want a low risk introduction. Move to a monotub when you are ready for larger, more consistent production and willing to manage the extra steps.
"I tell every new grower the same thing: the bag is not a lesser method. It is a different tool. I have seen beginners waste months fighting contamination in monotubs they were not ready for. A bag puts your first successful flush in hand and teaches you what healthy colonization actually looks like. That knowledge makes you a better monotub grower later."
What Sets an All in One Grow Bag and a Monotub Apart?
Back in 2009, before Out-Grow had a website worth showing anyone, I set up both systems side by side on a folding table in my garage because I did not trust myself to explain the difference to a customer until I had run both with my own hands. The bag sat there sealed and quiet. The tote needed grain, substrate, a hydration check, and a lid I had drilled myself. Watching them colonize side by side over the following weeks taught me more about what each method actually asks of a grower than any spec sheet could.
An all in one grow bag combines sterilized grain spawn and a bulk substrate inside a single pre-made sterile bag, usually with an injection port or self healing filter patch. You inoculate it, seal it, let it colonize, and then introduce fruiting conditions by cutting the bag or moving the colonized block. The vendor has already done the substrate blending, sterilization, and hydration. Your job is to keep it clean during inoculation and then manage the fruiting environment.
A monotub is a modified plastic storage tote, typically in the 25 to 45 liter range, used as both a bulk substrate container and a fruiting chamber. You mix colonized grain spawn into a pasteurized or sterilized bulk substrate, fill the tub, let it colonize, and then provide fresh air, humidity, and light through designed polyfill vents or modified lids. Everything from grain preparation to substrate hydration to contamination prevention is in your hands.
The table below shows how these two methods compare across the factors that actually determine which one fits your situation.
| Factor | All in One Grow Bag | Monotub |
|---|---|---|
| Steps before fruiting | Inoculate, seal, incubate. Minimal handling after that. | Grain prep or purchase, bulk substrate prep, mixing, tub setup, incubation. |
| Sterile technique required | Low. One inoculation event with the port or filter patch closed. | Moderate to high. Multiple open air steps add contamination opportunities. |
| Substrate type | Fixed by the vendor. Choose the formula (wood based, manure based, grain based) before purchase. | Grower selected. Pasteurized straw, supplemented sawdust, manure and coco coir mix, and more. |
| Yield per run | Limited by bag volume, typically 2 to 5 lb of substrate. Good for personal harvests. | Higher. Larger substrate volume and tunable conditions produce more mushrooms over multiple flushes. |
| Cost per harvest over time | Bags are single use. Recurring cost scales with production volume. | Tubs are reusable. Higher initial investment, lower cost per harvest over many runs. |
| Space needed | Compact. Works on a shelf or in a closet. | Moderate. A 25 to 45 liter tub plus optional humidification equipment. |
| Environmental control | Limited. Substrate composition and bag design are fixed. | High. Grower controls humidity, fresh air exchange, substrate depth, and casing. |
| Best for | First time growers, small personal harvests, minimal equipment. | Regular production, species that need substrate flexibility, experienced growers scaling up. |
I put that timeline in front of nearly every first-time bag buyer who asks how long this is going to take, because the honest answer is a range, not a date. Some species colonize fast in a warm closet, others take the full six weeks in a cooler room, and that variability is normal, not a sign something is wrong.
Are Monotubs Better Than All in One Grow Bags for Yield?
Two winters ago I set a bag and a monotub of roughly the same substrate volume side by side on the same shelf, just to settle an argument I kept having with myself about how big the gap really was. Yes, in most cases the tub wins, but the comparison is not as simple as people make it sound. Monotubs consistently outperform individual bags on yield per run because they hold more substrate volume and allow you to adjust conditions throughout the fruiting cycle. That control over humidity, fresh air exchange, casing depth, and substrate formulation translates directly into larger flushes and more productive total output over the life of a tub.
The tradeoff is that each additional step in the monotub process is also an opportunity for contamination to get in. When people say monotubs are higher yield, they are describing what happens when the process goes right. When the process goes wrong because of a contamination event during mixing or casing, you lose the entire batch. That does not happen as easily with a bag, because the substrate never sees open air after sterilization until you are ready to cut or fruit.
The chart below scores both methods on six key performance attributes, rated on a scale of 1 to 5 for each. These ratings are based on what the systems are designed to do well, not on any specific species or harvest claim.
The pattern is clear: these two methods are almost mirror images of each other. Where bags are strong, monotubs are weak, and vice versa. That is exactly why the right choice depends on what matters most to your specific situation.
How to Use an All in One Mushroom Grow Bag: Step-by-Step
My first all in one bag, the one I ran to make sure I could stand behind selling them, colonized in a closet that ran a few degrees colder than I expected, and I spent an extra week convinced I had done something wrong before the mycelium finally caught up. The process is straightforward, and that is the whole point. There are four real steps from the time you receive the bag to your first harvest. Here is what each one involves and where most problems come from.
The most common failure point in this entire process is the inoculation step, specifically using a needle that was not fully sterile or handling the bag near a contamination source. Everything after that is just maintaining the right temperature and humidity. The bag does the hard work. My own cold-closet colonization run was slow, not contaminated, and that difference matters: slow is normal, contaminated is not.
Setting Up a Monotub: What the Process Really Looks Like
My first monotub was a storage tote from the hardware store down the street, and I drilled the vent holes with a paint-stirring bit because I did not own a real hole saw yet. It worked, but it was not pretty, and it taught me that a monotub setup involves more steps than a bag, with each one requiring some skill. The process is not difficult once you have done it a few times, but it is not as forgiving as a sealed bag when your technique is off.
The basic sequence is: obtain or produce colonized grain spawn, prepare and hydrate a bulk substrate, mix spawn into substrate at a ratio of roughly 1 part spawn to 4 to 10 parts substrate by volume, fill your tub, let it colonize in the dark at 20 to 28 degrees Celsius (68 to 82 degrees Fahrenheit), and then introduce fruiting conditions through polyfill-stuffed vent holes or a modified lid once you see full colonization and consolidation. Most growers also apply a thin casing layer of perlite or coco coir on top to hold humidity and trigger pins.
The key advantages over a bag are that you can adjust the substrate formula for specific species, you control the depth and surface area of the grow bed, and you can intervene at fruiting (fan, mist, adjust the vent) to get the most out of each flush. A well-managed monotub of the same substrate volume as a bag will outperform that bag on every flush.
That tracker is exactly where I stood with my paint-stirred hardware store tote a few weeks into that first run, spawn and tub done, colonization underway, casing and fruiting still ahead of me and still the part I was least sure about.
Grow Bag and Monotub Compared: Ease, Cost, and Space
A customer at my register a few months back laid two receipts side by side, one for a single all in one bag and one for a tote, a bag of perlite, and a slab of bulk substrate, and asked me point blank why anyone would pay more upfront for the tub. It helps to rate each method against the factors that matter most for a situation like his. The dot rating cards below score both methods on ease of use, yield potential, and long term cost efficiency.
On cost, the bags have a lower upfront price per unit but become more expensive at scale because each one is single use. A plastic tote costs more to set up, but once you have a working monotub process, your cost per harvest drops substantially with each run because you are buying bulk grain spawn and loose substrate rather than pre-made bags. I told that customer the same thing I am telling you: his single bag was cheaper that day, but his tote would be cheaper by the fourth run.
How Many Flushes From a Mushroom Grow Bag vs Monotub?
A spent oyster block sat in a bucket behind my shop for three weeks one summer before I got around to soaking and casing it again, half expecting nothing. It threw a small third flush anyway, which is not the norm for a bag but was a good reminder that both systems will give you multiple flushes, they just behave differently over time. Most all in one grow bags produce one strong flush and a second smaller flush before the substrate is exhausted. Performance drops sharply after the second flush because the substrate volume is limited and the nutrients are concentrated in a fixed amount of pre-made material.
Monotubs, especially those using supplemented or layered substrates, can push three or more productive flushes before the substrate is fully spent, and some setups produce consistent harvests across multiple cycles because the grower can rehydrate, case, and otherwise maintain the fruiting surface. The tradeoff is that each time you open the tub to intervene, you add a contamination exposure event.
| Attribute | All in One Grow Bag | Monotub |
|---|---|---|
| Ease of first grow |
Very easy
|
Moderate
|
| Contamination resistance |
High
|
Lower
|
| Yield per run |
Limited
|
High
|
| Flush count |
1 to 2 flushes
|
2 to 3+ flushes
|
| Substrate flexibility |
Fixed by vendor
|
Full control
|
| Long-term cost efficiency |
Higher per harvest
|
Lower per harvest
|
| Space required |
Minimal
|
Moderate
|
Which Grower Scenario Fits Each Method?
At a mycology meetup a couple years back I watched two people arrive with almost identical goals, fresh oysters for the kitchen, and walk away planning completely different setups once they talked through their actual constraints. One had a studio apartment and a full time job. The other had a garage, weekends free, and a taste for spreadsheets. Neither was wrong. Here is how I would sort a room like that.
Use an All in One Grow Bag When:
You want one or a few personal harvests with minimal equipment. You are still learning what healthy colonization looks like and want to minimize failure points. You have limited space, specifically a shelf or closet rather than a dedicated grow room. You are not yet comfortable making and handling bulk substrate safely. You want to try a species or substrate formula before committing to a full monotub setup.
Use a Monotub When:
You want consistent, larger harvests from each run. You are comfortable with grain spawn preparation or purchasing colonized grain, and you can pasteurize a bulk substrate safely. You have enough space for a 25 to 45 liter tote and a basic fruiting setup. You are growing the same species repeatedly and want to dial in the substrate and environmental parameters. You are thinking about growing at a scale where per-harvest cost starts to matter.
The Common Path:
A lot of successful growers at Out-Grow follow the same trajectory I watched play out at that meetup. They start with one or two all in one grow bags to understand what healthy colonization looks like, what a real pin looks like, and how humidity and fresh air exchange feel in practice. Then they move to a monotub once they have that baseline and are ready to manage the extra steps. The bag is not a dead end. It is often the best education for the monotub that comes later.
Common Bad Advice About All in One Grow Bags and Monotubs
Every few months a batch of bags or a stack of tote lids comes back to Out-Grow with a story attached, and the story almost always traces back to the same handful of claims repeated at meetups, on forums, and in beginner guides. Here are the ones I see come up most often, and what is actually true.
You should always grow in a monotub because bags are for beginners.
Bags are not inferior to monotubs. They are optimized for a different set of priorities, specifically low contamination risk, minimal equipment, and small personal harvests. For someone who wants one or two yields per month from a closet shelf with no extra equipment, a bag is the right tool every time.
Sealed bags do not need any fresh air exchange for fruiting.
Even in a bag, fruiting requires gas exchange to reduce carbon dioxide and supply oxygen. Bags with no designed exchange tend to produce deformed or stunted fruit bodies. That is why the correct procedure involves cutting slits or partially opening the bag before fruiting, not leaving it fully sealed. Fully sealed bags without an exchange route are designed for colonization, not for fruiting.
Humidity should be at 100% during fruiting.
The recommended fruiting humidity for most edible species is 85 to 95% relative humidity, not 100%. Sustained 100% humidity increases bacterial contamination risk and can cause waterlogging on the substrate surface. Maintaining 85 to 95% with proper fresh air exchange is the standard that applies to both bags and monotubs.
Monotubs always get contaminated.
Monotubs have more handling steps and more exposure opportunities than bags, which is a real difference. But with clean grain spawn, properly pasteurized substrate, and basic sanitation during the mixing step, monotubs are entirely workable for beginners who are willing to follow the steps carefully. Contamination in a monotub is almost always procedural, not inherent to the container.
Relevant Out-Grow Supplies
If you are starting with an all in one grow bag, Out-Grow makes several formulas to match the species you want to grow. The All in One Mushroom Grow Bag 5lbs is the standard starting point, and the 10 lb version gives you more substrate volume for larger first flushes. The Mega Mix All in One Grow Bag combines grain and wood based substrate in one bag, which works especially well for wood loving species like lion's mane and oyster. You can browse the full all in one grow bag collection to compare formulas by substrate type.
For monotub growers, bulk substrate and grain spawn bags are the two building blocks. Out-Grow carries sterilized grain in rye, oats, millet, and a mega mix formula. On the substrate side, manure based, wood based, and pasteurized wheat straw are all available for the species that use them. You can also browse the full mushroom substrates collection to find the formula that fits your target species.
The Bottom Line
An all in one grow bag and a monotub are not competing products. They are different tools that fit different moments in your growing. The bag is right when you want your first successful harvest with minimal risk and minimal setup. The monotub is right when you are ready to invest more time and effort in exchange for larger, more consistent, and lower per-harvest-cost production. I have seen both methods work well and both fail badly, and the difference is almost always whether the grower chose the method that matched their actual situation rather than the one that sounded like it performed best on paper. Start where you are. Scale when you are ready.
About the author
Mike Wiberg is the founder of Out-Grow, a mushroom cultivation supply company he has run since 2009. He developed the original all in one mushroom grow bag in 2014, a format now used across the hobby, and over more than 20 years of hands-on mycology he has grown hundreds of species and researched substrate formulations from the lab bench. He maintains one of the largest commercial culture libraries online, including a working collection of more than 300 species under a USDA permit. His cultivation work has been cited in peer reviewed research published in Frontiers in Cellular and Infection Microbiology, and he is one of only a handful of growers with a documented successful clone of Matsutake, one of the most difficult species in cultivation. He has helped growers troubleshoot cultivation problems for nearly two decades, and he writes from the lab and the grow room, not from a keyword list.
Frequently Asked Questions
Beginners can use monotubs, but the learning curve is steeper than a bag. You need to handle grain spawn safely, pasteurize or sterilize bulk substrate, and manage contamination during mixing. Many beginner growers do better starting with a bag for one or two grows to understand how healthy colonization and fruiting look before adding those extra steps. That said, beginners who are careful and follow a clean procedure can run a successful monotub on their first attempt.
It depends on the species. Wood-loving species like lion's mane, oyster, and shiitake do well in wood based all in one bags. Manure based bags work for species that prefer nutrient dense, dung based substrates. Grain based bags work for a broader range of species and produce a very robust first flush. Choose the formula that matches the species you plan to grow, and check the product description for species compatibility before buying.
Most all in one grow bags produce one strong flush and a second smaller flush before the substrate is fully spent. Some species and bag formulas may offer a third light flush, but performance typically drops significantly after flush two. The limited substrate volume is the main constraint. If you want more total production from the same substrate, a monotub with a larger bulk substrate bed will outperform a bag over multiple cycles.
Most home growers use plastic storage totes in the 25 to 45 liter range. The standard 66-quart tote common at hardware and big-box stores is a popular starting point. The key dimensions to look for are a flat, wide base to maximize surface area for pinning, and sides tall enough to hold 3 to 5 inches of bulk substrate plus headspace for fruiting. Opaque or semi-clear both work, though some species respond to light cues and a clear tote can help you monitor colonization without opening.
The commonly used range in small-scale cultivation is 1 part grain spawn to 4 parts bulk substrate up to 1 part to 10 parts, measured by volume or weight. Lower ratios like 1 to 4 colonize faster and are more forgiving, but the substrate runs out sooner. Higher ratios like 1 to 10 extend the substrate life and reduce cost per batch, but require very clean technique because there is less inoculant competing against any contamination that gets in during mixing. Most growers starting out do well with a 1 to 4 or 1 to 5 ratio.
Yes, and many growers do this. You colonize the bag as normal, then open the top and place the bag inside a monotub or modified chamber to fruit. This gives you the contamination protection of the sealed bag during colonization plus the humidity and fresh air exchange control of the tub during fruiting. It is a reasonable hybrid approach if you want the best of both setups without committing fully to a bulk substrate monotub build.
You do not need a dedicated fruiting chamber for most all in one grow bags, but you do need to manage humidity and fresh air exchange during fruiting. Many growers put the bag inside a large clear plastic storage bin with damp perlite on the bottom to hold humidity. Others mist the interior of a small tent or closet. The bag itself is not a sealed fruiting chamber once it has been cut or opened, so ambient conditions matter. Without some humidity control, your pins will abort before they size up.
Oyster mushrooms grow well in both setups. An all in one grow bag with a wood based or straw based substrate is an excellent starting point because oysters are vigorous colonizers and relatively contamination resistant. A monotub with pasteurized wheat straw gives you more substrate volume and more flushes. If you just want fresh oysters for the kitchen from a simple setup, the bag is hard to beat. If you want to grow oysters consistently at volume, a straw monotub or a dedicated fruiting chamber with colonized straw blocks is more efficient long-term.