Simple Syrup Preservatives

[alacarte]

Hello old friends -- I'm trying to make a shelf stable simple syrup. What's the best way to preserve it?

When I made a batch a couple of weeks ago, it developed a fuzzy gray coating at the top - I'm assuming surface mold.

I've heard that sodium benzoate might work...but only if I also add citric acid?

I've also heard that ethanol might work.

Any molecular mixology experts out there have an opinion, or advice?

...and yes, I know that a good bartender would mix up a fresh batch of syrup, and wouldn't touch the preserved stuff.

[mkayahara]

You might find this post (and some of the others nearby) interesting. Specifically, this:

As I said above, increasing the sugar content is probably the best way to preserve your simple syrup -- especially if you are keeping it in the refrigerator. I've never been convinced that adding a few tablespoons of vodka to a pint of simple syrup would have any meaningful preservative effect on the syrup, as I don't see how it could possibly raise the alcoholic strength of the syrup enough to make a difference. I do, however, usually float a half-ounce or so of high proof spirits on the top of bottles of syrup that are going to be stored for a long time before I use them (for example, if I have two pint bottles of homemade grenadine). If the syrup is sufficiently concentrated, the spirits actually remain in a layer floating on top of the syrup rather than mixing in.

So it looks like ethanol isn't likely to be of much help. I'm curious, though: why are you looking to make it shelf-stable? Even a 1:1 syrup keeps pretty well in the fridge. Are you really that short of fridge space?

[slkinsey]

You will find more information about this in the simple syrup thread.

To sum up:

1. The best thing you can do to increase stability is to increase the concentration of sugar. Bars typically do a 1:1 syrup because it can be mixed up without heating, overpours are not as critical, and because they've got enough turnover that it's unlikely to spoil. For home use, I have found that 2:1 is far more stable. You do have to adjust the amount you use, however.

2. Refrigerate your syrup. I have managed to keep even 1:1 syrup for multiple months in the refrigerator in a bottle with an open pour top. I have managed to keep 3:1 syrups for months unrefrigerated in a sealed bottle.

3. Pour a tiny bit of high proof booze into the top of your syrup bottle once the syrup has cooled. Not sure why this works (the percent alcohol should not be enough to make much difference), but Dave W reports that it prevented funkage of his unrefrigerated syrup.

4. Citrus-infused syrups seem to last a long time if refrigerated. Herbed, spiced and gingered syrups don't tend to last as long without spoiling and/or serious flavor degradation. Things like mint syrup tend to taste weird almost immediately, IMO, and many "spicy" chemicals such as the ones that give ginger its distinctive bite degrade fairly quickly (for this reason I muddle fresh ginger with regular simple to-order). Very saturated fruit syrups made from already-pasteurized juices (e.g., >2:1 grenadine made from reduced POM) last more or less forever. Things like pineapple syrup made by soaking pineapple chunks overnight in simple syrup (4:1 if you're me) may not last very long.

5. I have taken to making my 2:1 syrups right in the bottle for added sanitation. Just put in your sugar and water, then put the bottle in the microwave on "reheat." Carefully monitor and turn the microwave off when the sugar is all dissolved. When the bottle cools, put in a pour top and refrigerate.

Edited October 20, 2008 by slkinsey (log)

[alacarte]

I want to brew up some fun, exotic flavors you wouldn't see in a store and give them as gifts. But that's no fun if they'll go bad right away.

[slkinsey]

What do you have in mind?

Grenadine is a good one. Easy to make, very stable if you make it highly saturated, and light-years away from the commercial stuff.

Edited October 20, 2008 by slkinsey (log)

[Chris Hennes]

Are there differences in preservation techniques for "exotic" flavors? I would think that a high enough ratio of sugar would make just about anything shelf-stable. Coupled with good sanitation during the production process, I don't see why various other flavored syrups would need different preservation techniques.

[alacarte]

I might use some jalapenos or other hot peppers. I've heard they can turn sulphuric though, so there's another factor.

thank you for the ideas, I appreciate it!

[bostonapothecary]

I want to brew up some fun, exotic flavors you wouldn't see in a store and give them as gifts.  But that's no fun if they'll go bad right away.

←

why don't you make a liqueur instead of a syrup... 20%+ alcohol will protect anything from bacterial spoilage... oxidation will be your only worry and you will have a good solvent...

Edited October 21, 2008 by bostonapothecary (log)

[Keith Orr]

Hello old friends --  I'm trying to make a shelf stable simple syrup. What's the best way to preserve it?

When I made a batch a couple of weeks ago, it developed a fuzzy gray coating at the top - I'm assuming surface mold.

I've heard that sodium benzoate might work...but only if I also add citric acid?

I've also heard that ethanol might work.

Any molecular mixology experts out there have an opinion, or advice?

...and yes, I know that a good bartender would mix up a fresh batch of syrup, and wouldn't touch the preserved stuff. 

←

Put the hot syrup in pint or quart canning jars and process it in a water bath canner for 15 or 20 minutes. Keep the open jars in the refrigerator. You can process fruit syrups the same way.

It seems like a whole lot of work for plain old simple syrup though.

[dsoneil]

After a little digging around, Potassium Sorbate / Sorbic Acid might do the trick. You can get it at your local wine making store and it's called "wine stabilizer". It prevents yeast and mold, which are your two concerns for simple syrup.

You can also look at paraben's, which are naturally occuring in nature and have a long history of safe use. Methylparaben is found in blueberries. However, this additive may be harder to source.

Cheers!

[brinza]

I don't know if the bottle the syrup is stored in makes a difference, but the first time I made simple syrup, I merely put it (mainly due to ignorance) in a glass bottle with just a cork and didn't refrigerate it. After a time it became moldy mainly around the mouth of the bottle and the cork. After that, I began keeping it in a small Drambuie bottle. I still don't refrigerate it, and it keeps for weeks--even a couple months--with no spoilage. Although my last batch was 2:1, prior to that I was making only 1:1 and it still didn't spoil. I get a little crystallization in the bottom of the bottle, but no mold. I don't know why that is, but there you have it.

[bostonapothecary]

After a little digging around, Potassium Sorbate / Sorbic Acid might do the trick. You can get it at your local wine making store and it's called "wine stabilizer". It prevents yeast and mold, which are your two concerns for simple syrup.

←

i've used potassium sorbate in wine making. you have to be careful because it can give off aromas... i don't think its a highly regarded trick by wine makers. i think its only used in cheap sweet wines.

i wonder if people's stability rates vary because of the differing amounts of mold spores in their houses?

[feste]

Put the hot syrup in pint or quart canning jars and process it in a water bath canner for 15 or 20 minutes. Keep the open jars in the refrigerator. You can process fruit syrups the same way.

It seems like a whole lot of work for plain old simple syrup though.

←

No, no, no! Hot water bath processing is only used for acidic foods. Grenadine and other fruit syrups are fine to process this way, as the acid prevents botulism and other food-borne diseases.

But botulism thrives in a low-acid environment. (Especially a high-protein one, so please don't process nut syrups like this.) Non-acidic foods require processing temperatures of 240' (rather then the 212' of boiling water), so to do it at home you need a pressure canner (different from a pressure cooker). This sufficiently eliminates these risks.

But yes, a lot of work for simple syrup.

[Keith Orr]

Put the hot syrup in pint or quart canning jars and process it in a water bath canner for 15 or 20 minutes. Keep the open jars in the refrigerator. You can process fruit syrups the same way.

It seems like a whole lot of work for plain old simple syrup though.

←

No, no, no! Hot water bath processing is only used for acidic foods. Grenadine and other fruit syrups are fine to process this way, as the acid prevents botulism and other food-borne diseases.

But botulism thrives in a low-acid environment. (Especially a high-protein one, so please don't process nut syrups like this.) Non-acidic foods require processing temperatures of 240' (rather then the 212' of boiling water), so to do it at home you need a pressure canner (different from a pressure cooker). This sufficiently eliminates these risks.

But yes, a lot of work for simple syrup.

←

Aaaack, Thanks for the correction - I know better. I meant to say process fruit syrups in a hot water bath. You should also check the pH to make sure it's 4.6 or lower - some fruits may not have enough acidity to achieve that low of pH. Most winemaking shops have pH strips to test the pH.

You'd have to use a pressure canner for anything with pH higher than 4.6

That's what I get for posting late at night

Edited October 24, 2008 by Keith Orr (log)