Friday, March 10, 2017

Using a pressure cooker for butter/oil extracts

I am pretty serious cooking enthusiast.  The inspiration for this recipe is from Modernist Cuisine, specifically this recipe for Garlic Confit. Here's a snapshot of that recipe.

After making this recipe which is amazing and also fairly simple, I thought the recipe could be adapted by substituting fresh weed or ABV for the garlic and clarified butter or coconut oil for the olive oil. You put both in a mason jar and put the mason jar in the pressure cooker. If you are going to make this, its worth checking out the Modernist Cuisine recipe page as well as this video which both show the recipe plus important basics on how pressure cookers work and pressure cooker safety.

Why a pressure cooker? The chart below from Modernist Cuisine shows that you can control the temperature you are cooking at by controlling the pressure inside the cooker. It allows you to use water / steam above the usual 212F.

By cooking inside a mason jar at 1 atm, I can cook the butter/oil at a constant ~250F. At this temperature for the right amount of time, I should not need an additional decarboxylation step. Also because the jar is sealed none of the lower-boiling terpenes, etc can escape into the air, as they can when you decarb in an oven.

So anyway, today I made a batch using ABV and clarified butter. Here are the steps:

1) Here is what I started with. 25g of ABV, a mason jar, my pressure cooker, and some soy lecithin. Sometimes I will grind up the ABV in a coffee/spice grinder but didnt feel like it today.

2) Then I made some clarified butter.


3) I added the ABV to one mason jar, covered it with (slightly cooled) clarified butter, and added a few drops of lecithin. Since I knew I was going to post, I weighed everything. It ended up being 215g of clarifed butter and 8g lecithin. Often if I have butter or coconut oil premade I will add it in solid form.


4) Then I put the lid on (leaving it a little loose to let pressure buildup escape ... see Modernist Cuisine article for details), put the jar in the pressure cooker, added water halfway up the jar, then closed the lid.


5) Got the PC up to pressure at 1 bar / 15 psi. Set a timer for 45 min at this pressure / temp combination. I'd be interested in others' thoughts on time / temp. My logic was to follow the decarb charts from 1990 that everyone seems to refer to, recognizing that it would take extra time to heat up everything inside the jar to temperature.


6) After 45 min was up, I used the quick release (faucet) method to cool things down quickly. I then opened the lid and took the jar out with a potholder. After letting it cool a little more I opened it up:


7) Then I strained everything into a silicone bowl and put the butter in the freezer to cool. I use a 100 micron "superbag" to get a fine strain. I suspect those of you that own bubble bags could use one of the finer mesh bags to do the same thing. Or just use a fine strainer. Or dont filter at all for that matter. I squeeze the bag a little to get as much liquid out as I can, but I know I am leaving quite a bit of potency in the bag. Licking your fingers at this point is recommended, but be careful since the butter is very concentrated and its easy to get very toasted very quickly.


8) After a few hours I take it out of the freezer and snap out the "puck" of ABV-butter.


I then vacuum seal mine, weigh it, and put it in the freezer until I am ready to cook with it. Today's puck was 134g, which is a little more than a stick.


This ends up being a pretty concentrated butter that I then use for caramels. My goal is to get something handheld, stealthy, and shelf-stable that has a full effect with one decent sized caramel.

Here's what I think are the advantages / disadvantages of this method:


1) No need to decarb separately.
2) Good temp control of process at ideal temp for decarb / extraction
3) Less cooking time than stovetop due to higher pressure extraction
4) Sealed jar minimizes leakage of volatile compounds normally lost during decarb / extraction
5) A pressure cooker can cost about the same as say, a magic butter machine, but its a multi-tasker in that you can cook lots of great regular food in it. I do risotto, refried beans, stews, chili, etc. In this regard a pressure cooker is much more stealthy in the kitchen than a dedicated machine for cannabutter.


1) Pressure cooking can be dangerous if you dont know what you are doing. Not that its unsafe or unmanageable, but anyone doing this should read up on how to use it and not leave it cooking completely unattended. Watch the MC video as a starting point.

2) If you dont like to cook or dont want to deal with a stove/pots/pans, something more turnkey like a magic butter machine may be a better option.

3) There's a risk that if you leave it cooking for too long at 250F, your THC will all turn to CBN. Now I originally started out cooking mine for two hours as with the garlic confit recipe. I thought it was pretty potent but have recently been cutting back the time for optimal results. That said, I also do a sous vide process where I decarb in advance and since the temps are lower (180-190), there is less risk of degradation there.

4) There is no agitation / stirring inside the mason jar when its cooking (magic butter machine wins here). I think its extracts nicely as is but theoretically more agitation should result in a better extract. I shake the jar before putting it in so that the butter and plant matter are well mixed.

Hope this is interesting / useful and would welcome thoughts/suggestions.  

Last edited: Aug 26, 2014