Mixing juices by weight Percent

[eHuman]

Dilution by Weight Percent instead of dilution by volume:

Accuracy: Using weight % by volume is the leading industry standard for blending and diluting complex chemical solutions to 4th decimal assay accuracy. I.E. An assay target of 12.34% (.1234) can be achieved using this method with equipment that I will recommend below.

Usefulness: May not be practical for typical hobby DIYer as the equipment can be cost prohibitive. Much more benefit to someone selling their product, nothing like getting a repeat order in and it not tasting right... Also to those individuals who just care to be as accurate as possible. And finally to those who just like to tinker. Once set up, this method takes no more time than the traditional dilution by volume method.

Benefits: Using weight percent dilution will accurately replicate a given taste regardless of the batch size.
Changing the batch size of a traditional volume ratio, or changing PG/VG ratio within the same recipe from batch to batch yields inaccurate replication of flavor. Weight percent dilution does not share this problem.

Importance: Very little to some, very important to others, it depends on who you are. Most people will find this method as overkill. Delicious flavors are made every day without it.

Why then? Maybe only because we can. I wrote this in part because I was asked to by an ECF member in a thread, but it came about due to some conversations about accuracy of batches based on drops. One thing lead to another and I brought this method up. As most all of you know, not all drops are created equal. What you may not know, is two drops of equal size may not be equal either... Volume vs weight.

WARNING:
If you are interested in the details of this method and are proficient in simple math, this will make sense. If not, I warn you now; Click the back button on your browser and continue reading other threads because this will glaze your eyes over.

Calculation of Weight Percent Formula:
(Weight of solute) divided by (total weight of solution) multiplied by (100%)
Example 1g of flavor (solute) and 19g (2nd solute) of base liquid: 1 divided by 20 (total solution) = .05 * 100% = 5% flavoring by weight. (Or if calculating base liquid content, 19 divided by 20 = .95 or 95%.
Does it look exactly the same to what you are already doing? In theory, but not in application. The percentages you are mixing are not what you think they are.

Example of “Standard “5% flavor dilution” calculated by volume:
5ml TFA vanilla to 95ml PG is a “5%” flavor dilution by volume
5ml TFA vanilla to 95ml VG is a “5%” flavor dilution by volume
5ml TFA vanilla to 95ml PG/VG 50/50 mix is a “5%” flavor dilution by volume
You will note that all of these recipes would yield a 100ml batch, but those flavor percentages are not accurate.

Example of same the 5% by volume flavor dilution above, calculated by weight giving the actual solution percentages instead:
5ml TFA vanilla to 95ml PG is a “4.01%” flavor dilution by weight
5ml TFA vanilla to 95ml VG is a “4.84%” flavor dilution by weight
5ml TFA vanilla to 95ml PG/VG 50/50 mix is a “4.39%” flavor dilution by weight
1. You can see that the dilution % changes when we mix with components of differing “Specific Gravity, or weight by volume . I.E. 1/20 does not necessarily = 5.
2. You will see that mixing by ratios do not represent actual percent of solution, (see below for math explanation.)
3. You will see that calculating by weight % represents the actual percentage of flavoring in the mixture, and is accurately repeatable regardless of batch size, so long as you have the means to accurately measure component weight. (Link below for example of an adequate digital balance).

Explanation information for Weight % dilution:
Every material including liquids have a different SG (Specific Gravity) or weight per volume. A liquid at 25% concentration will not weigh the same as it will at a 26%.

SG (Specific Gravity): (Assuming flavoring SG is equal to water, or “1”.)
SG of TFA Vanilla = 1 and weighs 8.34 lbs/gallon or 3782.96g/gallon
SG of 100% VG = 1.249 and weighs 10.5 lbs/gallon or 4762.72g/gallon
SG of 100% PG = 1.036 and weighs 8.62 lbs/gallon or 3909.966g/gallon
SG of 50/50 PG/VG = 1.1425 and weighs 9.56 lbs/gallon or 4336.343g/gallon
1 gallon = 7570.824 ml: (gallons and mls are both measurements of volume)

Volume to weight conversion for each ingredient in above example:
5 ml of TFA Vanilla = 2.499g (3782.96g/7570.824ml/gallon * 5ml)
95 ml of VG = 59.76g (4762.72g/7570.824ml/gallon * 95ml)
95 ml of PG = 49.06g (3909.966g/7570.824ml * 95ml)
95ml of 50/50 PG/VG = 54.41g (4336.343g/7570.824ml * 95ml)

Mils per gram conversion:
1g Flavoring = 2.00 ml
1g 100% PG = 1.59 ml
1g 100% VG = 1.94 ml
1g 50/50 PG/VG = 1.75ml

Grams per ml conversion:
1ml Flavoring = .5g
1ml 100% PG = .63g
1ml 100% VG = .52g
1ml 50/50 PG/VG = .54g

How do you handle solids like crystals?
1g of crystal melted in 4g of PG = 20/80 menthol/PG solution. For tight control, 20% of this flavor can be considered flavor and 80% of it as PG, but if this whole process isn't overkill that may just be.

So our new mixing formula looks like this. Very familiar, but done by weight instead of volume:
1g (2ml) TFA vanilla to 19g (30.21ml) PG is a “5%” flavor dilution by weight and yields a 32.21ml batch.
1g (2ml) TFA vanilla to 19g (36.86ml) VG is a “5%” flavor dilution by weight and yields a 38.86ml batch.
1g (2ml) TFA vanilla to 19g (33.25ml) PG/VG 50/50 mix is a “5%” flavor dilution by weight and yields a 35.25ml batch.
You will note that each recipe will yield a different volume batch.

A calculator can easily be made in a spreadsheet that allows you to enter:
Desired batch size in mls.
Desired flavor concentration %
Desired nic %
Desired end PG/VG ratio of mix.

And will give you the weight in grams for each solution component to be mixed.

Mixture can be completed in one bottle/vial/flask:
1. Tare (zero) out scale
2. Add 1st component to recipe weight
3. Tare scale
4. Add 2nd component to recipe weight
5. Repeat as necessary.

Equipment:
1. Typical DIY liquid transfer tools (pipettes/syringes/dropper/auto pipette), mixing bottles/flasks/beakers.
2. A precision digital balance is needed to take accurate measurements. (If you could only accurately divide 1 gram into 10 parts, it would hardly be of benefit. Being able to accurately divide 1 gram into 100 parts (for example) would be of great benefit.
3. Beware of .1g and 1g accuracy balances, they are not accurate enough for this purpose.

Example of an adequate balance:
Adam Equipment® - CQT 202 - $180.00 - Precision Balance - Affordablescales.com
This balance will weigh a maximum of 200g (or 7oz) with a .01g repeatable accuracy, or 1/100th of 1 gram, ability to divide 1 ml into many parts.

How does that translate to flavor % accuracy?
1 gram of flavor to 19 grams of base = 5% solution
1.01 grams flavor to 19 grams of base = 5.05% solution
1.02 grams flavor to 19 grams of base = 5.09% solution
1.03 grams flavor to 19 grams of base = 5.14% solution
1.04 grams flavor to 19 grams of base = 5.19% solution
1.05 grams flavor to 19 grams of base = 5.24% solution
1.06 grams flavor to 19 grams of base = 5.28% solution
1.07 grams flavor to 19 grams of base = 5.33% solution
1.08 grams flavor to 19 grams of base = 5.38% solution
1.09 grams flavor to 19 grams of base = 5.43% solution
1.1 grams flavor to 19 grams of base = 5.47% solution
Roughly 21-22 repeatable steps between 5% and 6% solution.

How do I find the weight of a liquid that doesn't have a C of A or MSDS available for it?
Take a known volume and weight it.

I hope that this is useful to at least one person, and entertaining or thought provoking to others. When we push the limits of what we CAN do, we end up finding things we were never looking for.

eHuman

 

[Cookster]

Simply AMAZING!

 

[Hoosier]

So, less flavoring, by volume, in a VG base will yield the same amount of perceived flavor compared to a PG base?

Have you tested this in RL to verify?

 

[Shilo]

I will stick to the calculator

 

[eHuman]

So, less flavoring, by volume, in a VG base will yield the same amount of perceived flavor compared to a PG base?

Have you tested this in RL to verify?

No I have not tried this method with juice flavors. But I have used it to make literally millions of gallons of exotic industrial chemicals. I have a US patent "Method for Continuously Blending Dilute Chemicals". Our recipes are generated using this method.

I'm not saying that 10% flavor in a 20/80 solution will taste the same (or different) as a 10% flavor in a 80/20 solution. They vape differently and impart different characteristics. What I am saying is that if you change your 40/60 base to a 60/40 base and keep all other things the same, you have a different juice. Maybe not one that our senses are acute enough to detect, and maybe not a difference worth the cost of a good balance and the effort.

I just put this out there because it's there.

The fact that flavor by volume can be 1% off what you think it is, is not a big deal. Getting good juices are. I presented this for those who may want to dabble and be able to repeat any recipe they have, on any scale, and have it be the same juice, because there is much room for error doing it by volume. (Again, not that we could taste the subtle difference. I brought this up because someone wanted to know why mixing by drops wasn't the most accurate method.

 

[Hoosier]

Ah, darn, I was hoping for a conventional wisdom breaker.

My only patent is for focusing wind energy so you know more about blending solutions than I do.

 

[eHuman]

Ah, darn, I was hoping for a conventional wisdom breaker.

My only patent is for focusing wind energy so you know more about blending solutions than I do.

Probably, but you've more than likely blended more that won't kill you than I have.
Like I tried to represent, this is more of a novelty, I doubt that our taste buds could detect the difference between the capabilities of this method of blending. But it is not so expensive an ordeal that it is impractical either. This method would be perfect for a person with OCD and a highly sensitive palette.

 

[Hoosier]

Well, there are some OCD types that are on this sub, and I've seen the subject come up before, so we'll see if it gains anymore traction this time around. I'm a bit set in my ways nowadays....

 

[windozehater]

i love this idea i just started diy'ng recently, and this has been on my mind, but getting it implemented was on my back burner still looking for that elusive perfect recipe. thank-you for adding to my OCD but seriosly you gave me more faith its possible. would love to be a fly on the wall at one of the big juice houses.

this is how we mixed paint in the autobody industry for years, fortunatly the specific grav. was always precalc. for us, except the idiots that would use volume measurements on the scale, then you have to explain what is heaver a gallon of cotton balls or a gallon of lead.

 

[StereoDreamer]

This is a fantastic thread, and something that anyone who is interested in "goiing pro" should read!

My only concern is that this technique seems to be pretty much impossible and impractical for people making small batches. If you are making 10m of liquid as a test batch, trying to figure out the weights by volume of such tiny amounts--and then actuallly DELIVERING such tiny amounts accurately into the mixing bottle--is almost impossible without some pretty sophisticated and expensive lab-grade equipment like digital pipettes and precision balance scales.

Although many DIYers wish we could afford several thousand dollars worth of Ohaus balances and Biohit digital pipettes, it's just not in the cards for us financially, and such gear would be necessary for mixing accurate, small batches. If someone is making batches of e-liquid on the industrial scale--by the liter or more--it makes sense though.

Thanks for this great info--I hope that many vendors see this, and adopt your method--it seems like it would greatly benefit batch consistency...

 

[AJK78]

Hi eHuman,

I'm the one who asked why drops weren't accurate. Thank you very much or explaining this. It seems DIY'ing will be more expensive than I imagined.

 

[eHuman]

Hi eHuman,

I'm the one who asked why drops weren't accurate. Thank you very much or explaining this. It seems DIY'ing will be more expensive than I imagined.

Please don't get that idea AJK, DIY can be as inexpensive as 1¢ a mil, and good flavors can be made mixing by volume the way most people do it. Not everyone wants or needs the accuracy that weight percent can provide.

Not everyone wants or needs a $400 PV, but some do, it's just an option and definitely not needed.

 

[eHuman]

This is a fantastic thread, and something that anyone who is interested in "goiing pro" should read!

My only concern is that this technique seems to be pretty much impossible and impractical for people making small batches. If you are making 10m of liquid as a test batch, trying to figure out the weights by volume of such tiny amounts--and then actuallly DELIVERING such tiny amounts accurately into the mixing bottle--is almost impossible without some pretty sophisticated and expensive lab-grade equipment like digital pipettes and precision balance scales.

Although many DIYers wish we could afford several thousand dollars worth of Ohaus balances and Biohit digital pipettes, it's just not in the cards for us financially, and such gear would be necessary for mixing accurate, small batches. If someone is making batches of e-liquid on the industrial scale--by the liter or more--it makes sense though.

Thanks for this great info--I hope that many vendors see this, and adopt your method--it seems like it would greatly benefit batch consistency...

Yes and no, an adequate balance costs under $200, a 50¢ syringe for coarse filling then we are limited by the drop weight that our smallest dropper/pipette can produce. A 26g luer tip can produce small drops. Technique can cut that in half, (syringing onto the wall of the bottle without touching it with the needle). A $150 precision pipette is not necessary. As for 10 ml batches?

Its under a total @200 investment to the person that already has DIY supplies.

 

[AJK78]

Please don't get that idea AJK, DIY can be as inexpensive as 1¢ a mil.

Nah, I just meant the starting costs really. € 115,00 for a ultrasonic cleaner, € 200-250 for a weighing device. I will start without weight percent and see how it goes. But if there are going to be noticable differences in consistency I'll probably end up with such a device. But even then the costs will be MUCH lower than buying premixed juices, let alone smoking analogs.

 

[flintlock62]

What eHuman said is correct concerning the accuracy of measurements. However, when making small batches (30 ml), and especially test batches ( 5 ml), using a syringe is okey dokey enough for most people.

When one is new to DIY, they are going to be experimenting with PG/VG ratios, and flavoring concentrations. At least that is what I do. One has to note too, that flavors with the same name will not taste the same from different vendors.

Syringes are cheap. Get yourself a couple of each size, 1ml, 3ml, 5ml, 10ml. Never measure by counting drops!

Like eHuman said, calculating by weight is more accurate, and if one is making ejuices professionally, then maybe his method should be considered. The weight method becomes more critical when larger volumes are manufactured, (i.e, gallons).

Hi eHuman,

I'm the one who asked why drops weren't accurate. Thank you very much or explaining this. It seems DIY'ing will be more expensive than I imagined.

 

[botakvap]

Grams per ml conversion:
1ml Flavoring = .5g
1ml 100% PG = .63g
1ml 100% VG = .52g
1ml 50/50 PG/VG = .54g

Totally noob (brain fart moment) question..
but isn't 1ml of liquid (be it flavor or PG) should be around 1g?

Sorry to bring up an old thread.

 

[Spazmelda]

If I recall correctly 1 ml of water is 1 gram, but this does not necessarily translate to other liquids. One ml of something that is mostly water (like soda or orange juice) is very close to 1 gram, but for things that are not water based 1 ml can weigh more or less than a gram.

 

[botakvap]

Thanks for the reply.
But wouldn't 1ml of flavouring be a around 1g and not 0.5g?

 

[windozehater]

everything has a specific gravity, now bear in mind a gallon can full of water vs a gallon can full of mercury, specific gravity is somtimes transposed with molecular weight. variations in density is why oil can float on water. to assume that pg/vg/flav. would all have the same volume to weight ratio would give bad mixes. weigh a empty syringe pull in 1 ml of whatever and weigh again then do the same fore the others, its not very accurate but it's better than not knowing. on a side note my guess is the vol/wt. ratio is not consistant between manufactures, i think we have all seen thick vg and than vg that makes honey look like solvent

 

[Spazmelda]

everything has a specific gravity, now bear in mind a gallon can full of water vs a gallon can full of mercury, specific gravity is somtimes transposed with molecular weight. variations in density is why oil can float on water. to assume that pg/vg/flav. would all have the same volume to weight ratio would give bad mixes. weigh a empty syringe pull in 1 ml of whatever and weigh again then do the same fore the others, its not very accurate but it's better than not knowing. on a side note my guess is the vol/wt. ratio is not consistant between manufactures, i think we have all seen thick vg and than vg that makes honey look like solvent

Ha, I was going to mention that as well, but I was reluctant to throw that variable out there. You've also got the hygroscopic nature of pg and VG thrown into the mix. I'd imagine it's pretty hard to get actual for realz 100% pg or VG (at least at vaping friendly costs). I bet they all have some varying percentage of water, either on purpose to make them less viscous, or accidentally because of water absorption. This is just a guess based on other hygroscopic materials I have worked with.

Edit: this is absolutely NOT something I worry about when making juices. I use volume/volume measurements and I'm okay with the lack of accuracy or precision, or whatever. It's good enough for vaping, IMO. Interesting to think of all these other things though.