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Decarb with an Instant Pot pressure cooker

Discussion in 'Cooking with Cannabis' started by PhilShifley, Sep 6, 2017.

  1. Ron

    Ron Active Member

    Messages:
    22
    Location:
    Canada
    I did this using a normal pressure cooker with I steamer insert and it worked great. My steamer keeps the jar out of the water, it gets heated by the stream instead. I used a small mason far with the lid tightened and then 1/4 turn loosened. My weed was dregs of various batches so I'm sure it had partially decarboxylated already. Due to the age of the weed I cooked it for 15 minutes only and let the pressure release naturally. No smell at all from the pressure cooker. The weed seemed a bit moist when the decarboxylation was complete so I tossed it in a toaster oven at 180f for minutes to dry it out. I then added a whack of coco oil and heated it up in an open pressure cooker (boiling water). When complete it had me stumbling while trying to use my treadmill, awesome!

    For those of you worried about ruining good weed try out your setup with an empty jar and make sure it seals and is dry at the end.
     
  2. lyttlefish

    lyttlefish New Member

    Messages:
    3
    I tried a method posted in another thread. You use pint canning jars instead. It works great. You decarb for 40 minutes with a quick release and you cook with butter or oil for 20 minutes and let it release pressure naturally over 40 minutes.

    I am concerned that the canning jars might explode..has anyone had a problem with this?
    Also I am new to this whole system. When I want to decarb, do I just put the aw weed in the jar or veggie cooker ? Is there no liquid required?Sorry to sound so naive. <')))><
     
  3. EdibleNewbie

    EdibleNewbie New Member

    Messages:
    5
    See my post below.

     
  4. EdibleNewbie

    EdibleNewbie New Member

    Messages:
    5
    You need to put the metal trivet in, sit the jar on the trivet, the fill the Instant Pot with water until it is about half way up the jar.
     
  5. lyttlefish

    lyttlefish New Member

    Messages:
    3
    thank you , I will give this method a try.
     
  6. pxl_jockey

    pxl_jockey Barely-Known Member

    Messages:
    949
    Location:
    Lost in the English countryside
    Sealed mason jars with trivet works a treat! I don’t need a special seal for my own dastardly intentions.

    Someone expressed concern about canning jars exploding; there’s absolutely no danger of a canning jar exploding in the IP. Its pressure is nowhere near that of the pressure required for canning vegetables and fruits which is what the jars are meant for.
     
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  7. Blacksmoke

    Blacksmoke New Member

    Messages:
    1
    wondering if a vacuum on the jar may compensate for altitude
    I know a vacuum on a liquid makes it boil at lower temps
     
  8. Ron

    Ron Active Member

    Messages:
    22
    Location:
    Canada
    For every 1000 feet of altitude gain yhe temperature that water boils at will decrease by 2 degrees Fahrenheit.
     
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  9. Ron

    Ron Active Member

    Messages:
    22
    Location:
    Canada
    My last post is incomplete. Figure out your altitude and then look at the graph posted previously to estimate how much time you need to cook for a proper decarb. I don't think jar vacuum makes a difference to decarb.
    I'm just over 1000meters or 3300ft so my regular pressure cooker reaches 250f - 7f =243f . So my pressure cooker (not instant pot) will boil around 243f. Guesstimating the time I need from that graph I need 30 to 35 minutes to decarb.

    Does that make any sense?
     
    Last edited: Nov 17, 2018
  10. Vital

    Vital Well-Known Member

    Messages:
    316

    :myday: I don't think I would go so far as to say "absolutely NO danger" of a canning jar exploding. If for example there is a slight unseen crack or the jar was manufactured with a flaw or imperfection in it than the jar most certainly could shatter. Always be careful when working with a pressure cooker especially with glass. :2c:
     
  11. CurryLeafTreehugger

    CurryLeafTreehugger Well-Known Member

    Messages:
    161
    Shattering NOT= exploding. Yes, a damaged jar can break, and it is more likely to break when you remove a hot jar and place it on a cold surface. Always use something like a folded towel or cork trivet - or better yet let the jars cool before trying to remove them from the pressure cooker. I like jar lifters but they're really for quart size and up jars, which won't fit in an Instant Pot anyway. Well maybe one would fit if your IP is tall enough. You might be able to get a couple in the largest Instant Pot, which I THINK is 8 quarts. I think the "regular" size is 6 quarts, and the Instant Pot mini is only 3 quarts I think. That's capacity of the liner, not the size of the jar you can fit in. I'm pretty sure you'd be limited to half pint jars in the IP mini and I'm not 100% positive the regular IP is tall enough for a quart jar.

    How do I know this? I grew up canning produce from our very large garden for our family of 7. In a huge honking actually-pressure canner. Yup, them was the good ol' days - spending the better part of a month to a month and a half canning in the August heat and humidity back when AC was something only fancy department stores had, LOL!

    Keep in mind that devices such as the Instant Pot DO NOT reach normal pressure cooking pressures. I believe the Instant Pot tops out at 8 to 11 PSI, as opposed to the 15 to 20 PSI my pressure canner ran at (and in fact ALL my old timey jiggler pressure cookers). The Instant Pot won't get as hot as a regular pressure cooker.
     
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  12. Vital

    Vital Well-Known Member

    Messages:
    316



    Hmmmm...I don't recall that I said it would "explode". I could have sworn I said "absolutely NO danger".


    :horse:
     
  13. HarkW2000

    HarkW2000 New Member

    Messages:
    2
    Hey, so I had a few thoughts on the forgoing. Sorry to make my very first post a self-important wall of text.

    With regard to the ideal decarb temperature curve, I personally am inclined to take the 1990 chart with a grain of salt. It is from the legit chromatography journal seen at the top of the widely circulated .jpg, but I have to think the "hexane extract heated in an open reactor" part is very relevant to anyone whose decarb scenario is different, e.g. all of us decarbing raw or cured flower. I've heard people make the argument that the THC molecule is the THC molecule, but I'm pretty sure the physical setup of the experiment and the medium the THC was in had an impact on the results.

    Second, there's a great thread here with people sharing experiences with Ardent's decarb machines, and specifically, one poster does a partial teardown of one, measures the heating/time profile with a thermocouple, and has before-and-after lab results that (nearly) match up with the promotional literature's claims of a full conversion. That being the case I think it's a pretty good argument (for those of us who can't currently afford an expensive one-button appliance) that that temperature/time curve is (if not necessarily the theoretical ideal) at least so good as to get near-100% conversion of cured flower.

    Specifically, the temperature curve (when the poster isn't using a container inside the appliance) heats up to a max of 118°C, then drops down to 113°C and bobs between those two temperatures for its working period. This is pretty strongly suggestive of it having a thermostat target of 115°C (239°F) that is cycling the heat on and off.

    The duration, if one includes the 20 minute warmup but not the unpowered cooldown, is around 1h25m with some variations between tests. This is notably longer than the very often cited 240°F-for-40-minutes guideline. Possibly the appliance is just taking longer than required, but it's a precise figure with an attractive lab result, which is more than I ever read for 240-for-40. (I gather that there are lab results in the "Another Tincture Thread" resource, but I was never sure how to navigate through that.)

    Given this fairly precise curve (and positive test results) this seems to me like the curve I want to try to emulate. Obviously the thermostat on a kitchen oven isn't going to cycle nearly accurately enough, but with an in-oven thermometer positioned next to the weed container (good quality ones are inexpensive) and an "open the door periodically" thermostat I'm guessing I can get fairly close to the mark. I'm awaiting a thermometer order now. A toaster oven would obviously be handier for the same experiment, with its smaller air volume to manage and less temperature variation in the smaller space. I'm inclined to take Ardent's claims that "ovens and toaster ovens do a bad job" with a grain of salt: the language is rather vague and I suspect what they mean is "letting any old crummy oven thermostat regulate the temperature is inadequate." That may be perfectly true, but the casual implication of their lit is that oven/toaster oven decarb is necessarily wasteful to the tune of 15-33% of THC. If a 10 dollar oven thermometer and 70-80 minutes of babysitting the process can approximate 100% conversion, that's kind of a different story.

    Third: people were discussing using mason jars for decarb. I know this is common (just as non-weed related cooking and "oven-canning" applications with mason jars are common) but it's worth mentioning that the manufacturers of mason jars specifically tell people that oven use (as opposed to the lower temperature water canning methods) aren't safe and shouldn't be attempted.

    Mason jars are thick annealed glass and probably the vast majority of times they'll work in this application, but they're not designed for it and they don't have safety features either in terms of how they shatter, or any special properties in terms of resisting thermal shock, which is the main draw with different kinds of pyrex.

    (Different eras and manufacturers of "pyrex" [soda lime glass] and "PYREX" [borosilicate glass] have different tolerances for thermal shock and, as a practical measure, different oven temperature safety guidelines. I believe both are fairly safe around the 115°C/239°F temperatures we mostly talk about here.)

    If people are bound and determined to use mason jars I hope they at the very try to avoid rapid heating and cooling scenarios, which is what tends to cause the most dramatic thermal shock shattering.

    Lastly: for moderately smell-conscious people, my experience has been that an aluminium-foil covered PYREX pie plate was surprisingly effective at keeping an oven decarb from stinking up the kitchen. There was an aroma around the oven but nothing very powerful or lingering, certainly less than when I just put the weed on a cookiesheet.
     
    Last edited: Dec 4, 2018
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  14. HarkW2000

    HarkW2000 New Member

    Messages:
    2
    Also: if anyone has ready access to a lab (or the money to just mail it off) I would think that a demonstrably ~99% decarb process with lab results, using only kitchen appliances and a thermometer, would make a great how-to article pitch to Leafly or a similar informational website.

    Given Canada's legalization framework, there must be a ton of people out there looking to decarb cured flower simply and efficiently, without being tied to a specific cooking or infusion method.

    (Sitting in the kitchen opening a toaster oven door at regular intervals for 70-80 minutes may not be everybody's idea of simple. But the low cost, high efficiency and flexibility of the end product surely count for something.)
     
    Old Toker likes this.

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