Citric Acid Ersatz for Lemon Juice

[Rossum]

I recently started adding a bit of lemon juice to some of my liquids. I like the way it reduces the nic's harshness. But I don't like what it does to my coils -- I suppose due to sugars in the juice? Anyway, I thought I'd make up an aqueous solution of straight citric acid to use a substitute.

So I googled. Typical lemon juice seems to be 5-6% citric acid. And various sites indicate that 1/4 teaspoon powdered Citric Acid is equivalent to 1 tablespoon of lemon juice. But one or the other of these can't be right.

A teaspoon is 5ml. So 1/4 teaspoon is 1.25ml. A tablespoon is 15ml. So if I wanted to make a 30ml bottle of lemon juice substitute, I should use 2.5 ml of citric acid, right?

But... 30ml of DW is 30 grams. And 5% of 30 grams is 1.5 grams. And the density of citric acid in in solid form is between 1.5 and 1.6. We'll use 1.5 because a powdered substance has some air space it it and it keeps the math easy. So 1.5 grams of powder should be 1.0 ml.

Somehow, the two approaches give me a factor of 2.5 difference.

Anyone know which is right?

 

[IDJoel]

2.4975 grams is what my math says (so yeah; 2.5g):

• Citric acid has a specific gravity of 1.665g per mL/cc/cm{cubed}
  
  per wiki.
• My distilled water weighed out at 10.140g/10mL tonight (or 1.014/mL)(measured on a powder scale freshly calibrated and read-out to 0.001 grams).

So, for easy numbers, Let's make a 100mL batch of 5% (5 parts; not to be confused w/Ph) citric acid:
05 parts/mL X 1.665g = 8.325g citric acid ...... (8.325g X 0.30 = 2.4975g for 30mL batch size)
95 parts/mL X 1.014g = 96.33g distilled water (96.33g X 0.30 = 28.899g for 30mL batch size)
100 parts/mL total ........................................ (100/mL X 0.30 = 30mL)

I am sure the citric acid purity plays into it; this would be for 100% pure. I just checked what I had bought from Bulk Apothecary, and it is listed as 99.9% pure, so there would be a 0.1% variance. I doubt those little bottles of lemon juice are that precise.

 

[Rossum]

2.4975 grams is what my math says (so yeah; 2.5g)

Correct me if I'm wrong, but it seems like you're trying to calculate 5% by volume, which you're actually going to measure it out by weight?

I'm trying to do the opposite. I'm thinking the 5% should be by weight, but since I'm a barbarian who doesn't use a scale for his DIY, I'd like to measure it by volume.

 

[DaveP]

Correct me if I'm wrong, but it seems like you're trying to calculate 5% by volume, which you're actually going to measure it out by weight?

I'm trying to do the opposite. I'm thinking the 5% should be by weight, but since I'm a barbarian who doesn't use a scale for his DIY, I'd like to measure it by volume.

Most thin liquids equate closely to 1 gram per millimeter in the juice calculators. You might want to weigh a ml to see. VG is numerically heavier than its milliliter volume, but PG is close.

Even though you mix by volume it might be convenient to own an inexpensive scale for times when you need to verify weight and volume.

BotBoy's DIY page addresses weight and volume for various components used in DIY. There might be some helpful info there.
Botboy141 Guide to Mixing By Weight • r/DIY_eJuice

When it comes to flavors, there are a couple of thoughts/theories surrounding mixing by weight when dealing with flavors. Many people enter the specific gravity as indicated on an MSDS for every flavor that they have. I feel this is a complete waste of time. After searching hundreds of MSDS sheets for flavors, all flavors fall into a range of .93g per ml to 1.07g per ml.

In order to achieve personal consistency for your juices though, all that is relevant is that you use the SAME value, every time for any given flavor. I simply use a value of 1. This means that whether or not my flavors actually weigh 1 gram per ml, I always pretend they do. Percentages in any given recipe of mine will always be the exact same for me, however, if I am trying to recreate someone elses recipe, or they are mixing mine, there's a chance I'll be off a little bit (no more than 7% which is about the margin of error most people get when mixing by volume).

 

[DaveP]

This link might also be of help. There's a Citric Acid Dilution Chart with percentages at the link.
http://www.rpc-rabrenco.com/assets/documents/Dilution.pdf

 

[IDJoel]

Correct me if I'm wrong, but it seems like you're trying to calculate 5% by volume, which you're actually going to measure it out by weight?

I'm trying to do the opposite. I'm thinking the 5% should be by weight, but since I'm a barbarian who doesn't use a scale for his DIY, I'd like to measure it by volume.

Yes, you are correct, I was going for weight. My bad; I get hung up on measuring dry ingredients by volume. As you pointed out:

a powdered substance has some air space it

The various citric acid I have purchased has varied greatly on crystal size; and therefore airspace surrounding the crystals. I am too ignorant to know if it would help to grind, or crush, the crystals (thereby reducing air space size)? Or, if any benefit is lost/offset, because of the increase of more (though smaller) air spaces?

I can only guess (anecdotally) that courser is better, from what I know about subbing powdered sugar for granulated sugar. "Acceptable" substitution tends to range from 1.75 to 2 parts powdered for 1 part granulated.

My not understanding how to account for the "air space" variables is what makes weight more appealing to me. I am afraid I don't have any useful advise for volume; sorry about that.

If you have any family, friends, contacts, that would have access to an appropriate scale (DIYers, ammunition re-loaders, lab techs, pharmacists, science educators, etc.); you could pay them a visit, along with your citric acid and preferred measuring instruments, and find out what actual weights the measuring spoons are giving you. Then you could apply that information to future volume mixing.

Additional thought after re-reading your OP:

IF you accept your original understanding that 1/4 tsp. equals 1Tbls. of bottles lemon juice (at 5-6% citric acid), and you wanted to make 2 Tbls. (29.5735mL) of solution:

Why couldn't you take a small graduated cylinder (or some other reasonably precise measuring vessel of your choice) and add your half teaspoon of citric acid (which "should" have a metric volume of 2.4645mL without any airspace) and then add your distilled water (or whatever dilutant you choose) that you pre-measure (such as using a syringe) to the required 27.109mL volume (29.5735ml total volume - 2.4645ml citric acid volume = 27.1090mL dilutant volume) that should be required to make the total intended volume. Any measured shortage of the total volume should have been introduced by the unaccounted-for air pockets and can then be compensated for by adding additional citric acid.

DISCLAIMERS:

• I provided way more decimal points than is either practical, or probably, desired. I wanted to provide adequate data so you could round up as you saw fit.
  
• I am sure I am WAY overthinking this for what you are likely wanting to accomplish; but I tend to do that. Please feel free to adapt, or ignore, as you see fit.
• Truthfully; any dilution will work. You simply need to adjust the amount you add based on the potency of your solution. The important thing is that you can replicate your solution in the future so you don't have to constantly readjust your recipes.
  
• I am sorry for hogging up all the thread space. It was a fun exercise.

 

[Rossum]

If you have any family, friends, contacts, that would have access to an appropriate scale (DIYers, ammunition re-loaders, lab techs, pharmacists, science educators, etc.); you could pay them a visit,

I do have access to a reloading scale up in PA, but I'm not there right now and probably won't be for a while. So at the moment, spending $20-$25 on a scale at Amazon strikes me as a lower-resistance path than trying to find one to use here.

Why couldn't you take a small graduated cylinder (or some other reasonably precise measuring vessel of your choice) and add your half teaspoon of citric acid (which "should" have a metric volume of 2.4645mL without any airspace) and then add your distilled water (or whatever dilutant you choose) that you pre-measure (such as using a syringe) to the required 27.109mL volume (29.5735ml total volume - 2.4645ml citric acid volume = 27.1090mL dilutant volume) that should be required to make the total intended volume. Any measured shortage of the total volume should have been introduced by the unaccounted-for air pockets and can then be compensated for by adding additional citric acid.

I think you've convinced me that measuring this stuff by volume is a bad idea. Plus I have a fuzzy recollection that volume of of a solution doesn't always increase in direct proportion with the volume of solutes added to the solvent.

So yep, I think I'm going to order that scale, weight out 1.5 grams of citric acid, add about 25ml of DW, dissolve the CA, and as the last step, add however much water it takes to bring the volume up to 30ml.

 

[IDJoel]

I think you've convinced me that measuring this stuff by volume is a bad idea.

I have to apologize; I never meant to give you that impression. It is my own obsessive compulsive (read: ....-retentive) nature that doesn't like having an unknown result. I didn't want to transfer my own hang-ups on you. There should be no reason why you can't do it by volume. You can find all sorts of posts for diluting EM crystals; so I would think it should be no more difficult with citric acid crystals. Maybe that is what I get for trying to think.

I don't see any reason why you can't choose a ballpark amount (e.g. 1/2 teaspoon/30mL) and be in an workable neighborhood. (I would be genuinely curious what the acceptable variation is for store-bought lemon juice.) The only important thing (in my eyes), is that you are able to repeat your results with regularity, so you don't have to be constantly tweaking your recipes.

Anything further is probably only a minor bonus.

 

[Rossum]

I think I could accept +/-10%. Maybe even 20%. But a 2.5:1 factor of uncertainty is too much. Getting the scale will allow me to eliminate that uncertainty and determine effective density of the CA I have.

 

[Capt.shay]

I think I could accept +/-10%. Maybe even 20%. But a 2.5:1 factor of uncertainty is too much. Getting the scale will allow me to eliminate that uncertainty and determine effective density of the CA I have.

Your destined for the way of the weigh Rossum. It just makes so much sense once your comfortable with it.

 

[Rossum]

Your destined for the way of the weigh Rossum. It just makes so much sense once your comfortable with it.

LOL -- you should see how I mix now. A pinch of this and a dash of that.

OK, not really. I use a graduated cylinder to make my unflavored base and I actually do count drops of flavorings -- when I use flavorings at all.