Soda syrup preservative?

Figbash · 01-02-2009, 04:37 AM

I have an old fashioned soda fountain that uses soda water and hand pump syrup dispensers. The Coke syrup I use works fine but any syrups that I make myself spoil too quickly. Is there anything I can add as a preservative to keep them fresh?

Tom

bucket · 04-11-2011, 12:46 AM

sodium benzodite or citric acid. sodium benzodite mix at 1:32 parts or citric acid at 1:512 would keep syrups from going bad. A home made syrup goes bad after 1-2 weeks with these chemicals it changes it to a year.

Omegaman · 11-19-2011, 07:22 PM

Hi bucket, I have a few questions. You said:

sodium benzodite or citric acid. sodium benzodite mix at 1:32 parts or citric acid at 1:512 would keep syrups from going bad

First off, I am wondering if you meant sodium benzoate, I have never heard of sodium benzodite. I would have assumed it was just a typo, but you typed benzodite twice. Is there such a thing?

Then you gave the ratios, but failed to mention of that is by weight or volume. Which is it?

If you were talking about sodium benzoate, I read that the max dosage is .1% by weight (limited by the FDA), and a 1:32 ratio by weight or volume, would be way off. Sodium benzoate usually comes in a solution I think, the source I looked at sold it in 25% solution. In that case, a liter of liquid (specific garvity of 1.0) would have 4 CCs or 4 grams of sodium benzoate, which is a ratio of 250:1. Thirty two to one would seem to be about 8 times the maximum dosage.

Now, I admit that I have no idea what I am talking about so take all of this with a grain of salt ( we need to do our own research and not just take others words for it). That being said, I do not know how to implement these dosages into practicality. I believe the dosage as I specified it above, is intended to be the ratio in the final food product (not in a flavor concentrat for example. Now, here is why that might be important, at least this is my thinking. I assume that that ratio is sufficient to act as a preservative. That should be true (I think) whether that is in a flavor concentrate, or the final product (soda), though I am not positive of that. Since the preservative is is working to protect ingedients from spoiling, and water does not spoil, can it be that you can dose the concentrate at that ratio and not add more when it is diluted with water? Just a question. It is possible that that concentration needs to be in the final product (my guess) in order to be sufficent to offer protection.

Also, since sodium benzoate and vitamin C form benzine ( a carcinogin ) being carefull with concentrations is a good idea. Health is an issue when messing with chemicals, so let's be careful.

I also read that for Sodium Benzoate to be effective, it has to be in an acidic substance, that may be why citric acid is added to foods (besides the flavor). Even though acids have their own preservatice powers, they might be present to make the sodium benzoate effective.

As little as I know about sodium benzoate ( and nothing about sodium benzodite ), I know less about citric acid. So I will not question the dosage you suggested there.

Thoughts?

MrFoodScientist · 11-21-2011, 05:55 PM

Actually 25% is 250g Sodium Benzoate and 750g water per 1000g solution, not even close to 4g per Liter.

The 0.1% limit is on a weight basis for the finished product. (So something like commercial sodas)
Bear in mind that this is the maximum level permitted in commercial products, and may be way over the effective level to achieve what you need. I'd recommend starting with that and backing down from there. If you have .1% or less in your syrup, it will only dilute further in your beverage. The actual rate of spoilage is going to be determined by your actual ingredients, sanitation practices, and storage/handling conditions. So you'll probably want to experiment. If you start at .1%, you will probably notice what's referred to as "preservative burn", a subtle stinging sensation/aftertaste at the back of your throat indicative of too much preservatives. If you're not familiar with this sensation, grab an energy shot like the Monster Hitman product and you'll see what I'm talking about.

So if your basic recipe is something like
8 lb sugar ( 3.63kg)
1 gallon water (3.63 L)
then you'd want 7.26g Sodium Benzoate in your syrup.
With a 25% solution, you'd only need 29g of solution in your basic recipe, I'd guess that's somewhere between 1 and 2 Tablespoons. (1TBSP pure water = 14.77 mL, so your solution will be more dense meaning heavier per TBSP)

I hope that helps.

Omegaman · 12-21-2011, 08:40 PM

Thanks MrFoodScientist