Purchasing the best pressure cooker for mushroom cultivation necessitates a keen eye on certain attributes: its capacity, the material from which it's crafted, and its pressure rating. Given that pressure cookers often represent the priciest purchase for mushroom enthusiasts, thorough research before investment becomes essential.
A common misstep many new mycologists make is settling for a pressure cooker, only to realize its limitations a year down the line. This guide seeks to shed light on a range of options tailored for both beginners and seasoned mushroom cultivators.
Before committing to a purchase, familiarizing yourself (how to use a pressure cooker for sterilization) with the intricacies of using a pressure cooker for sterilization can be invaluable. Such knowledge ensures you're not just buying a tool but also mastering its application.
Our Top Picks – At A Glance
If you’re looking for the perfect pressure cooker for mushroom cultivation, the Presto 23-Quart Pressure Cooker is the best for most usecases. It offers excellent functionality and versatility, allowing you to pasteurize up to four 5-liter buckets of straw or create up to 26 half-pint grain jars in a single sitting, whilst being reasonably priced.
This makes it a great choice for mycologists who need to handle a large amount of substrate or spawn.
The Presto 23-Quart Pressure Cooker has a solid reputation and is considered a reliable choice by those who are serious about cultivating mushrooms. It’s an investment that’s unlikely to be outgrown, and it’s definitely worth considering if you’re in the market for a pressure cooker for your mushroom-growing journey.
The Instant Pot is ideal for novices, thanks to its two key features: a timed shut-off for hands-off operation and accurate temperature regulation for pasteurization.
Once the sterilization is complete, the Instant Pot turns itself off, offering convenience and efficiency.
This detailed breakdown “Instant Pot for Mushroom Cultivation” highlights the many benefits of using an Instant Pot and how it can simplify the cultivation process, making it an invaluable tool for beginners.
This Presto 16 Qt pressure cooker offers a solid reputation and impressive capacity, its the budget version of the 23 Quart Presto, making it a reliable choice for mycology.
Additionally, its affordable price point and 15 psi pressure gauge make it an excellent value for those looking for an effective and budget-friendly option.
Comparing Pressure Cookers for Mycology and Mushroom Cultivation.
In this section, I have examined and handpicked a selection of pressure cookers and sterilizers tailored for mycology. Based on our experience with each product we have highlighted a short list of products we recommend above and a detailed analysis of 10 products below.
Below, we focused on key attributes for spawn sterilization, such as jar capacity, user-friendliness, weight, and availability, among others. Our aim is to encompass all the essential considerations that any budding mushroom cultivator might weigh before investing in a pressure cooker or sterilizer.
Our objective is to facilitate an educated choice, ensuring you select the product that perfectly aligns with your mushroom growing endeavors.
Note: If you decide to make a purchase through any Amazon links provided, I'll earn a small commission at no extra cost to you. Thank you for your support!
Large options (20-23 Quarts)
Every choice in this section comes with my highest recommendation, garnering a 5★ rating. Each of these options offers ample space for a substantial amount of mushroom spawn, and their capacity and performance ensure they'll serve you well in the long run, regardless of how your needs may evolve.
Material: Aluminium.
Size: Large. 14.8 inches Height, 15.1 inches Diameter, 22 Litres
Weight: 5.6kg
Racks included: 1 (recommended to buy a second one here).
Hob Type: Electric, Gas, Smooth top, Induction.
Available Location: USA, UK (Find it on eBay).
Full pressure time: 10 minutes.
Warranty: 12-year limited warranty.
Capacity: 9 x 1000ml jars, 26 x 1/2 pint jars
We checked the capacity using a rack that was provided by the manufacturer and a second rack which can be purchased here.
Here is a picture of me stacking 10 x 1 litre jars inside the 23 quart presto.
My Thoughts.
Most serious mushroom cultivators purchase a 23 Quart Presto as they are reliable, huge and hold a lot of substrate.
This whopping pressure cooker should hold at least 20 half-pint jars meaning you can create a whole lot of spawn in one go.
If space isn’t an issue I would recommend this cooker.
The Presto 01781 23-Quart is 23 cm tall and 32cm in diameter. It has been manufactured using extra strong aluminum and weighs 5.6kg.
It is important to check you are going to be able to store this unit before buying it.
You will need a space with 42cm width and 37 cm of height to comfortably get it in and out of a cupboard.
To do this I turn the lid upside down to avoid damaging the pressure dial and make it fit as shown in the images below.
Once it is filled with gain jars and water it definitely becomes more difficult to handle; make sure you are prepared to lift and move it around the stove (while full) when you use it.
I usually place the cooker on top of my stove, then fill it with contents to avoid heavy carrying, however, there are still instances where you may need to shift it on the stove.
The Presto 01781 includes three main parts, these are:
The Pressure Gauge can help you ensure that you are sterilizing your mushroom substrate over 15 psi. 
The Vent Pipe, this is a pressure release valve that will release pressure in excess of 15 pounds. The pressure regulator sits on top of the vent pipe.
The Pressure Regulator, which is basically a small weight that prevents the pressure cooker from exceeding 15psi.
Sometimes mycologists will place a few coins (quarters) on top of this to allow it to exceed and remain over 15psi for extended periods, however I have found this necessary.
The original pressure regulator does rattle a lot when you get up to the top temperatures and some feel the need to upgrade it to a non rattle regulator.
Air Vent Lock, this is a lock which will pop up when pressure inside the cooker has built beyond a certain point. Once the Air Vent lock pops up the pressure regulator will begin moving upward.
The prices for Presto canners can vary a lot. Even on Amazon, you’ll find different sellers selling the same model for very different prices. It’s worth shopping around the cooker often goes on sale for a cheaper price so look out for it around the sale periods.
What We Like
- Ample Capacity: Its size allows for the production of a significant amount of grain spawn in one go.
- Value for Money: The product is priced reasonably, especially considering its size.
- Efficient Pressure Build-up: Achieves the desired pressure quickly.
- Reliable Warranty: The product comes with an outstanding warranty.
- Pressure Gauge: Provides visibility, ensuring that sterilization levels are achieved.
What We Don’t Like.
- Noisy Regulator: If the temperatures aren’t exactly at 15psi, the pressure cooker regulator can become quite noisy, rattling intensely.
- Manual Pressure Regulator: The Presto utilizes a manual regulator. This might be challenging for beginners due to its multiple moving parts.
- One rack: but you can get a second one here.
- Requires monitoring: While in use this system should be monitored, unlike something like an instant pot.
Material: Aluminium.
Size: Large. 16.26 inches Tall, 15.39 Inches Diameter, 22 Litres
Weight: 8.2kg
Racks included: 2
Hob Type: Electric, Gas, Smooth top, Induction.
Available Location: USA, UK, and EU.
Full pressure time: 10 minutes.
Warranty: 1 year limited warranty.
Capacity: 16 x pint jars, 26 x 1/2 pint jars
In the realm of mushroom cultivation, efficient sterilization is pivotal. The T-Fal 22 Quart pressure cooker rises to the challenge, especially for those dealing with substantial batches. Not only does it have an impressive capacity, but it also boasts a dual-rack inside the box – a definite advantage straight out of the box.
What truly distinguishes the T-Fal is its intuitive yet professional design. Gone are the days of manually placing a pressure regulator weight over a valve. Instead, this cooker introduces a dial-based system, streamlining the pressure-setting process before heating.
For those concerned about handling and safety, the central handle placement atop the unit, combined with generously-sized side handles, ensures optimal grip. These design considerations facilitate safer lid removal, minimizing contact with hot metal.
A noteworthy safety feature is the cooker’s vent-controlled locking mechanism. While seasoned cultivators know the importance of allowing units to cool post-sterilization, this addition offers an added layer of protection against premature opening and potential steam burns.
In terms of build quality, the T-Fal outshines competitors like Presto. The robust feel, augmented by a heftier lid, suggests longevity and durability.
Unlike some cookers that might disturb your workspace with incessant rattling, the T-Fal guarantees a serene operation. Yes, there’s a slight hissing sound, but a touch of practice in positioning and temperature-setting will ensure consistent pressure and noise reduction.
The inclusion of two racks, eliminating the need for an additional purchase, offers undeniable value. Further sweetening the deal is the 10-year warranty – a testament to the brand’s confidence in its product.
For serious mycologists seeking a blend of capacity, functionality, and user-centric design, the T-Fal 22 Quart pressure cooker stands out as an exceptional choice.
What We Like.
- Safety First: Notably robust safety features, particularly beneficial for pressure cooking novices.
- Generous Capacity: Its vast size enables the production of large grain spawn batches in a single session.
- Value for Money: Competitively priced, especially given its impressive size.
- Efficient Pressure Achievement: Attains the desired pressure swiftly and reliably.
- Stellar Warranty: An outstanding warranty underpins its quality.
What We Don’t Like.
- Pressure Gauge Limitations: Older models utilize a 1-2-3 gauge system, lacking a specific PSI pressure gauge.
- Cumbersome Size: Its substantial weight might pose handling challenges for some.
- Manual Shortcomings: The accompanying user guide leaves room for improvement.
Material: Aluminium.
Size: Large. 18.5 inches Tall, 16.1417 Inches Diameter, 23.6 Litres
Weight: 6.7kg
Racks included: 2
Hob Type: Gas
Available Location: USA, UK (eBay only).
Full pressure time: 10 minutes.
Warranty: 10-year limited warranty.
Capacity: 19 x pint jars, 38 x 1/2 pint jars
The All American 925 isn’t just another pressure cooker on the market; it’s a genuine autoclave, akin to what you’d find in professional lab environments tailored for sterilization. Given its unique utility, it naturally warranted a spot on our list.
This unit shines with unparalleled craftsmanship. Eschewing the common rubber seal, it’s ingeniously designed with a metal-on-metal seal for the lid. Such a design eliminates the typical wear and tear issues associated with rubber components, promising longevity. If you’re aiming for an investment that lasts, the All American 925 won’t disappoint.
Equipped with two racks, it allows for efficient double stacking of jars. You can easily accommodate a minimum of 26 jars without incurring additional costs for extra racks. Those looking to embark on producing spore syringes, liquid cultures, grain spawn, or agar plates for trading or selling, this is your go-to equipment.
Yes, at first glance, it might seem formidable, but it promises foolproof sterilization for all mycological needs for years to come. Just a word of advice: familiarize yourself with its operation by perusing the manual and viewing instructional videos as it has an interesting locking system.
Basic Operating Instructions:
- Add 2-3 inches of water (note: it’s more water-efficient than other units).
- Lightly lubricate the metal-on-metal seal using a Q-tip dipped in olive oil.
- Securely fasten the cover with the six sealing screws. For even pressure, alternate between tightening opposite screws.
- Position the autoclave on a burner and set it to high heat.
- Set the regulator weight to the 15psi mark.
- Be vigilant for any leaks during operation.
- Once at the desired pressure, the regulator weight will start to jiggle. At this point, monitor the PSI gauge closely.
What We Like.
- Professional-Grade Sterilization: Designed as a true autoclave, offering lab-grade sterilization at home.
- Superior Craftsmanship: Metal-on-metal seal eradicates the typical issues associated with rubber seals, ensuring longevity.
- Ample Capacity: Comes with two racks, allowing for double-stacked jars, and can accommodate a minimum of 26 jars without additional racks.
- Long-Term Investment: Designed to stand the test of time, especially due to the absence of easily perishable rubber components.
- Efficient Water Usage: Requires only 2-3 inches of water for operations, making it more water-efficient than many counterparts.
What We Don’t Like.
- Intimidating for Beginners: Its professional design might seem daunting for those new to sterilization processes.
- Manual Familiarization Required: The necessity to read the manual and watch instructional videos to fully grasp its operations.
- Physical Bulk: Given its robustness and capacity, it might be heavy and cumbersome for some users.
- Monitoring Required: Close attention needed, especially during the initial uses, to ensure there are no leaks and pressure is consistent.
Your mushroom cultivation projects deserve the best, and the All American 925 might just be the partner you need.
Medium options (10-18 Quart)
These choices are ideal for beginners on a budget who are willing to invest a bit more because of their dedication to the hobby.
Material: Aluminium.
Size: Large. 17 inches Tall, 11 Inches Diameter, 15 Litres
Weight: 4.5kg
Racks included: 1
Hob Type: Electric, Gas, Smooth top, Induction.
Available Location: US, UK (eBay only).
Full pressure time: 10 minutes.
Warranty: 12 Year limited warranty.
Capacity: 14 x 1/2 pint jars, 10 x pint jars.
You can’t double stack in this pressure cooker, however it is possible to create a base layer then place a few jars on top on their sides, as show in the picture we took during our testing below.
The Presto 16 qt pressure cooker strikes a perfect balance for those just delving into mushroom cultivation.
Its size is thoughtfully designed: substantial enough to produce a commendable batch of grain spawn in one go, yet compact enough to ensure easy storage and maneuverability.
Equipped with both a pressure gauge and a regulator, it reliably hits the 15 PSI mark — a crucial feature for mycological practices.
Presto’s sterling reputation in the mycologist community speaks volumes. In fact, it’s frequently hailed as the premier pressure cooker for beginners.
For many, an investment in this model proves to be enduring; they find that they never need to upgrade, reflecting their unwavering satisfaction with its performance.
What We Like.
- Affordable: Priced accessibly for its features.
- Quick Pressure Buildup: Achieves 15 PSI efficiently.
- Reliable Warranty: Offers a comprehensive guarantee.
- Clear Sterilization Indicator: The pressure gauge clearly signifies when sterilization levels are reached.
What We Don’t Like
- Noise Concerns: If temperatures aren’t optimized at 15 PSI, the regulator can become noticeably noisy.
- Limited Capacity: Accommodates only one stack of jars.
- Requires Constant Supervision: Contrary to some electric counterparts, this model demands ongoing monitoring during operation.
Material: Stainless Steel.
Size: Large. 12 inches Tall, 11.6 Inches Diameter, 12 Litres
Weight: 4.5kg
Racks included: 1
Hob Type: Electric, Gas, Smooth top, Induction.
Available Location: US.
Full pressure time: 10 minutes.
Warranty: 10 Year limited warranty.
Capacity: 12 x US ½ pint Jars. 4 x US 1 Pint Jars.
You can’t double stack in this pressure cooker, however it is possible to create a base layer then place one or two extra SMALLER jars on top on their sides.
Mirroring the safety features of the previously mentioned T-fal unit, the Zavor EZLock pressure cooker stands out for its strong safety emphasis — a boon for those unfamiliar with the sterilization process.
Its locking mechanism is rather groundbreaking: the lid secures innovatively via the top handle, a design distinct from most conventional pressure cookers.
A safety vent is built into the design, providing an avenue to release any excess pressure as it builds, enhancing the safety quotient.
Unlike the Presto models, which can appear a tad intimidating due to the need for placing a separate pressure regulator, the EZLock offers a more user-friendly interface. Simply set your desired pressure on the dial, heat it up, and the cooker will handle the rest. Once it begins to hiss, indicating optimal pressure, it only requires a slight heat adjustment to maintain.
Its capacity is quite decent, accommodating up to four 1-quart jars, allowing a substantial amount of spawn creation in a single cycle.
Crafted from durable stainless steel, its robust construction is backed by a 10-year warranty, attesting to its longevity.
And, paramount to the entire process, it efficiently reaches the critical 15 psi threshold essential for effective sterilization.
What We Like.
- Enhanced Safety Features: Designed with an emphasis on user safety.
- Innovative Lid Design: Unique locking mechanism not typically found in conventional models.
- Strong Warranty: Offers a comprehensive guarantee for long-term peace of mind.
What We Don’t Like
- Higher Price Point: This model tends to be more expensive compared to similar products from other brands.
- Pressure Gauge Concern: Ensuring accurate sterilization levels can be a bit challenging, as the pressure gauge is critical to monitoring the process.
Electric Pressure Cookers.
Electric pressure cookers have come a long way, evolving significantly year by year. After recently acquiring an Instant Pot, I've discovered its immense potential as an indispensable tool in mushroom cultivation.
It's worth noting that most electric pressure cookers on the market currently don't sustain a true 15 psi, typically hovering around 12 psi. But this shouldn't deter mycology enthusiasts. By simply extending the mushroom spawn sterilization cycle, one can achieve remarkably consistent results.
What sets electric pressure cookers apart is their inherent safety and ease of use. Compared to their stovetop counterparts, they demand far less hands-on monitoring, making the cultivation process less cumbersome and hands-off for a hobby grower.
Material: Aluminium.
Size: Large. 14.8 inches Tall, 13.3 Inches Diameter, 36 Height
Weight: 7.2kg
Racks included: 1 pot
Hob Type: None (electric plug in).
Available Location: Globally.
Full pressure time: 15 minutes.
Warranty: 1 year warranty.
Capacity: 7 x 330ml jars, 2 x 500ml jars
Looking back on my journey in mushroom cultivation, if I had to choose a first pressure cooker again, the Instant Pot 8Qt would undoubtedly be my pick.
- Sterilizing Grain Spawn? While it might take longer than a standard 15 psi pressure cooker, the Instant Pot offers a more relaxed and nearly hands-off approach.
- Pasteurizing Substrate? Simply set it to the sous-vide function within the pasteurization range, add your substrate, and return three hours later to find the job perfectly done.
- Need to Keep Agar Warm? This unit has got you covered.
- Sterilizing Utensils? Check that off your list with ease using the Instant Pot.
The Instant Pot 8Qt feels like a comprehensive solution tailored for the home-based mushroom cultivator. While it might not be the first choice for commercial setups or expansive farms, for hobbyists and enthusiasts, it’s a near-perfect blend of versatility and convenience.
What We Like.
- Versatility: The Instant Pot serves multiple purposes, from pasteurization and sterilization to maintaining agar at the right temperature.
- Safety: Its design prioritizes user safety, reducing risks associated with pressure cooking.
- Stove-Free Operation: No need for an additional stove, offering greater flexibility in where it’s used.
- Hands-Off Approach: Designed for a “set-and-forget” experience, requiring minimal supervision.
What We Don’t Like.
- Limited Capacity: Its ability to accommodate jars is somewhat limited.
- Size to Capacity Ratio: The physical size of the unit seems somewhat disproportionate to its internal holding capacity.
- Pressure Limitations: It doesn’t consistently maintain the ideal 15 psi.
Further reading:
Material: Aluminium.
Size: Large. 14 inches Tall, 15 Inches Diameter, 14 Height
Weight: 7.98kg
Racks included: 1 pot
Hob Type: None (electric plug in).
Available Location: USA.
Full pressure time: 15 minutes.
Warranty: 1 year warranty.
Capacity: 7 x 330ml jars, 3 x 500ml jars
The CAREY DPC-9ss offers a straightforward, 15 psi pressure canning experience powered by an electric outlet. While it might not boast the multifunctionality of the Instant Pot, its ability to serve as a pressure canner for meats suggests its proficiency in achieving a full 15 psi sterilization — making it potentially ideal for grain spawn preparation.
What We Like.
- Efficient Operation: Achieves a steady 15 psi.
- User-Friendly: Straightforward and simple to use.
- Hassle-Free Cleaning: Features a detachable pot for easy cleanup.
What We Don’t Like.
- Limited Versatility: Primarily designed for the singular function of sterilizing spawn jars.
Small options (6 – 8 Quart)
Several pressure cookers on the market cater specifically to newcomers. While they aren't expansive units, they're ideally suited for those keen to experiment with the PF-Tek method or craft a modest batch of grain jars.
Take, for example, my 7L Tower pressure cooker: it comfortably houses 3 x 1L grain jars or 8 of the smaller counterparts. Such a capacity is likely a perfect fit for hobbyists taking their initial steps into mushroom cultivation. Plus, the compact design of these models makes storage a breeze compared to their bulkier counterparts.
Material: Stainless Steel with aluminium base.
Size: Large. 8 inches Tall, 8.5 Inches Diameter, 15 Litres
Weight: 1.7kg
Racks included: 1
Hob Type: Electric, Gas, Smooth top, Induction.
Available Location: US.
Full pressure time: 10 minutes.
Warranty: Lifetime warranty.
Capacity: 7 x 330ml jars, 2 x 500ml jars
The Cuisinart CPC22-8 stands out as an 8-quart pressure cooker, equipped with a lid design akin to the Zavor EZlock, echoing its high standard of safety. This feature marks it as a prime choice for budding mycologists apprehensive about the inherent risks of pressure cooking.
This model is particularly budget-friendly, making it a perfect fit for individuals exploring mycology as a potential hobby, allowing them to experience the craft without a significant financial investment.
Reaching 15psi, it possesses the capability to sterilize grain jars effectively. However, its relatively compact size means it’s more suited to producing smaller batches at a time.
Its compactness not only relates to its usage but also its storage, being a convenient option for those with limited storage space, and perhaps envisioning its use on a more sporadic basis throughout the year.
While it may not align with the needs of someone establishing a mushroom farm, it holds significant appeal for hobbyists seeking a versatile, user-friendly introduction to the world of mycology.
What We Like.
- Enhanced safety features.
- Unique lid design.
- Generous warranty coverage.
- Affordable price point.
What We Don’t Like.
- Limited capacity.
- Disproportionate unit size relative to jar accommodation.
Material: Aluminium.
Size: Large. 7 inches Tall, 9.5 Inches Diameter, 15 Litres
Weight: 2.2kg
Racks included: 1
Hob Type: Electric, Gas, Smooth top, Induction.
Available Location: US.
Full pressure time: 10 minutes.
Warranty: 1 year warranty.
Capacity: 6 x 1/2 jars, 2 x 500ml
The Presto 8 qt stands out as one of the most affordably priced yet dependable pressure cookers available. It’s an ideal choice for those on a tight budget or newcomers to mycology who are hesitant to invest heavily.
What We Like.
- Exceptionally affordable.
- Presto’s renowned quality.
- Achieves 15 psi.
- User-friendly handle and lid mechanism.
What We Don’t Like.
- Limited capacity – not ideal for large batches of spawn.
- Shorter warranty than typical Presto models.
Pressure Cookers For UK Mushroom Growers?
It is possible to import the Presto 23 quart to the UK I got mine on ebay (find it on eBay here), the price was a lot more than the USA but I definitely don't regret it.
Small
Tower T920004S7L Express 7 Litre Pressure Cooker
This is the size pressure cooker I started out with its cheap and can hold about 8 half pint jars. This is a well built system and are designed to ensure safety as a priority, this can be a huge benefit to people new to the sterilization process.
On this type of pressure cooker the design is more simple and “safe” with a pressure locker and a release valve which cannot be blocked.
This system build pressure and slowly releases it from the valve so it is important to fill the unit to the correct water levels.
Do you need a Pressure Cooker for growing mushrooms?
Technically no, I have a full post on how to grow mushroom without a pressure cooker. Here you will learn the various work around if you don't want to buy a pressure cooker.
If you want more consistent results and to grow an array of different strains, using all the methods available it is always recommended to use a pressure cooker.
What size Pressure Cooker Is needed for Growing mushrooms?
The minimum size pressure cooker needed for mushroom growing is 6 Quart, this will allow you to get 6 half-pint Jars sterilized at one time.
What to look for in a Pressure Cooker for growing mushrooms?
-
Capacity: Gauge the size of the pressure cooker based on the number of mason jars it can accommodate. The larger its capacity, the more spawn jars you can sterilize at once, leading to a more efficient mushroom cultivation process.
-
Pressure Capabilities: A critical feature to look for is the ability to achieve 15 PSI, the necessary pressure level to elevate the internal temperature enough to sterilize the substrate. While many European models might hover around 14 PSI, they can still be effective if you extend the sterilization time slightly.
-
Compatibility with Your Stovetop: Confirm that the pressure cooker is compatible with the type of stovetop or hob you use at home. While numerous models are designed for universal use, some may not be suitable for specific stovetops, so it's vital to double-check.
Why is a Pressure Cooker important in mushroom cultivation?
Pressure cookers sterilize the substrate destroying harmful contaminants which could compete with your mycelium.
Pressure cookers are important when growing mushrooms as they sterilize the different substrates which the Mycelium is going to eat. Contaminant such as mold spores, bacteria and other fungi spores are everywhere and the substrates we use during mycology are the perfect nutritional meal for them. When the correct moisture and nutritional conditions are met (after we soak the substrates) the spores and bacteria germinate and multiply, taking over your substrate.
By heating our substrates to a high temperature in the pressure cooker we are destroying the spores and bacteria which may have been present on the substrate. This will give the mycelium you introduced into the substrate a head start to establish itself before reintroducing the substrate to the contaminated open air again.
Conclusion.
Hopefully this was helpful if you made it this far then you must be really motivated to start growing mushrooms!
Checkout our recommended equipment section.
2 thoughts on “Best Pressure Cookers For Mushroom Cultivation.”
great review i just love it
I am trying to buy a pressure cooker but am severely limited by funds, being on a low, fixed income. So I am looking at used or cheap models. The sticking point seems to be pressure and with some of the cheaper ones I cannot find their operating pressures. Is there any disadvantage in using a cooker which will not reach 15 psi, even if cooking for a longer time, or is the absolute temperature reached the critical point ? Appreciate any advice.