Oven vac temp and time for shatter

Hello, first time using a vac oven from best value vacs. I was just wondering vac times and temps to make shatter

Ethanol or butane shatter?

Butane shatter

Heres my old school technique: This is strain dependent usually.

I start my oven around 95, until I break muffin. This temp can vary up to 98-100f, even possibly. Try to stay on the lowest temperature that you can.

After I break muffin and can vac down fully, I start at 91f for 24 hours. I flip every 12 hours, & vac down fully after each time.

I then bump my oven temps up every 6-12 hours by 1-2f, depending on how the oil is reacting, up to 97f until finished. I usually have my oil in the oven for a good 72 hours.


Those slabs looks awesome. Is that trim or nug run?


@HanSan has a good process in place, definitely follow that.

Once thing I notice that plays the biggest part in getting shatter is keeping the temp lower. If the temp goes too high, terps start to offgas and you’ll almost always get wax or crumble. Keeping the temps around 90-95 is the sweet spot in my experience.

I don’t flip, I just purge the slab for 3-4 days and get the same results.

I put it in the oven when bubbling has pretty much stopped, pull a vac to around -20 until it muffins, then I let the muffin settle and continue to pull to full vac. I’ll then just leave it at full vac for a few days, making sure I run the pump for ~5 mins every hour or so during the day. Once I get no reaction, or just tiny bubbles left, I’ll remove and test it out, make sure it dabs fine.


Thanks👏 These were made with some decent larf material. I ran the same batch of trim as well, and it yielded the slab maybe barely one shade darker than these.

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When I get an unknown strain I purge at 78f never trying to pull a muffin. Low vacuum until it degasses enough not to muffin then pull deeper vacuum. Try not to finish above 85f. Strains that have heavy terps don’t need so much deep vacuum. Making shatter is very strain dependent if your not controlling a lot of factors . Agitation and heat are your enemy’s with stable shatter


My apologies in advance for being blunt and appearing to be confrontational, but what is the scientific reasoning behind advocating such low temperatures?

Why would an extremely long vac purge at <100F where the oil is thick retain more terpenes than a short purge at 115F where the oil is fluid? Why would the percentage of butane to terpenes being released be different?

Is this some effort to sell more vac ovens, lol.

Here’s my take from another thread on the subject, and a link to that thread:

I purge BHO at 115-120F at down to -29.5" Hg in a thin film until the bubbling slows to a crawl.

The short explanation:

The 115-120F is to ensure the oil is in liquid state for the butane to easily escape the matrix.

The down to -29.5" Hg means I don’t ever pull past this point. I don’t leave the pump running, which would take the vacuum down to -29.9", which I believe is unnecessary as the 115-120F @ -29.5" Hg is deep enough to remove any moisture, and pulling a deep vacuum on and on possibly disturbs the matrix leading to waxing up. I go for shatter, and consider other products unfortunate ‘accidents.’ But feel free to cook up whatever waxes, budders, honeycombs, crumbles you want, just don’t expect me to buy into them as premium grade product.

This process will get you to below the residual butane solvent standards as quickly/efficiently as possible, further purging is unnecessary imo, and I’ve presented a long and thorough case for my opinion in a single thread previously.

“At what ppm can you taste butane?”

Having observed the trend to these low temperature and exceedingly long purges over the years, I think they came about as knee jerk reaction to slabs waxing up, with no one ever questioning how ridiculous, and without scientific basis the rigmarole is.

It’s long been both Gray Wolf’s and my opinion that the oil needs to be fluid to get the butane out in an expeditious manner, and that ~115F does so well without major loss of terpenes.

If there is such a difference in the loss of terpenes between purging at 85F versus 115F, then on a large slab you should be able to weight the slabs and prove it.

And… if you’re going to say purging at 115F leads to waxing up,


Of course you can apply 115f heat and be done in 24 hours passing residuals. But the thing is some strains happen to end up very oily at that temp and if the demand is high for it to have some sort of shatter consistency even if it’s for two weeks before it sugars. What should I do? I have found only way is to not stretch it and get no muffin and not apply any heat if at all any . For every square foot I only purge 25-35 grams so it’s super thin. If you pour thick IMO you for sure need high heat. After 3 days I still get slightly dirty results compared to budder but our customers don’t care when asked as long as they get that strain in that flavor. What you recommend instead?


There is some strains I have been able to purge at 110 and been done in 36 hours hardly any residuals. But some strains that are very pungent I have done 110 and it becomes like goo and has te be frozen after to remove from paper and becomes a mess . I might be missing something

Why not pull a muffin?

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Butane can be noticed at 300 to 350 ppm

I’ve had the same thing happen to me. That’s why I’m trying to not take the temp over 105F but the little bubbles still won’t come all the way out! I’ve flipped the slabs about 20 times with about 45-1 hour in between each flip.

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Sometimes if the lil bubbles dont come out. I put my slab on the bottom if the oven no vac for a couple hrs


I’ll try that, thanks

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Essentially that’s just increasing the temperature with no vac, right? Because the floor and ceiling of the oven are hottest.

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Probably, no sure if temp is ambient or surface. But i believe you are increasing temp

If you tryna remove every bubble and look like glass you need a heat gun and slightly heat the slab after came out of oven careful not to go over 100f and all bubble will pop or can also leave in oven for like 30min after release of vacuum


Some of the people say they purge for 38 hours and shit I know it depends on the size of your run but I’ve always purged at higher temp like bout 150 and vacuum for bout two hours at 110 and then bubbles gone no more reaction at all. The shatter tastes amazing and is always pull and snap never waxes up. Been doing it for five years no issues or complaints. The one time I tried to do it at lower temp 90 and let it purge for two days(cause it’s not hot enough to extract any faster) the shatter was awful and definitely not fully purged. Never again. I literally did it cause I was reading to see if there are any new ideas out there cause when I started It was limited. Don’t fuck with something you know works. Went back to my old method and perfect golden glass again, tasty pull and snap.