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
