A refract can tell you the dissolved solids level - which you may be able to correlate to your particular formula's Aw, but it's difficult to say any product with a dissolved solids level of xx = an Aw of yy. You may be able to make some educated guesses - for example, you may be able to take a range of products off the shelf and get a sense for their dissolved solids level, and try to emulate it on your product hoping to get 'in the ballpark' - but remember, a refract requires transmissible light for it to work, so you may need to work out a dilution as chocolate/caramel sauces aren't particularly translucent. also note that many shelf stable items may have preservatives in them, which, along with thermal processing and Aw control, becomes part of that mfr's stability strategy.

Thanks Sebastian for the great insight. I guess I need to revisit some of Jean Pierre Wybauw's books as he writes extensively about measuring AW. I might even look into facilities that do testing.

I definitely fall in to the very small category. I am wondering if measuring the sugar density of a caramel sauce or chocolate sauce can determine if it is safe. It will be a lot easier for me to buy a refractometer verus getting theAWequipment.

Has anyone on this forum successfully preserved achocolate sauce or a caramel sauce that was shelf stable. When I go to specialty stores I often see these sauces by small producerson shelves and I wonder how they do it.

That, my friend, is the subject of many textbooks. I'd suggest doing some research on water activity (Aw) to familiarize yourself with the basics and what the various ranges indicate. You can have your product tested at any number of facilities, or you could purchase your own equipment, but they're often more than folks want to send to purchase.

If you're a very, very small operation (ie you make 5 jars / year out of your house), you may want to take the 'make it, store it, and watch it' approach to see what the typical amount of time is before it goes south. not very scientific i know.

Thanks Sebastian! I really appreciate this info. Your post brings up more questions...How does one measure the AW of a product (without purchasing very expensive equipment)? Could a refractometer, that measures the sugar density, do the job? If so, at which measurement is the product ok to be jarred and shelf stable? You also mentioned heat treatments. How would that work? Would I put sauce into sterilized jar and then put into a pressure canner? Would a steam set up in the oven work? How long would it need to be heat treated? Could the heat treatment cause the sauces to separate? Sorry for all the questions. There seems to be very little information out there about safely jarring products with dairy products.

You'll need to control your water activity, which you won't know what it is until you have it tested. Once your Aw is low enough, microbes won't be able to grow. If you're unable to reduce your Aw to satisfactory levels via your formulation, you'll have to give it a heat treatment to kill everything in it, or keep it refrigerated.

I am interested in preserving homemade chocolate sauce as well as caramel sauce. Both of these items contain dairy products. I have been researching preserving techniques and I see that both chocolate and caramel sauce have been declared unsafeto preserve as these items are low acid and contain dairy products. I certainly don't want to create a hazard. Isn't there enough sugar in caramel sauce to make it safe to preserve? What about chocolate sauce? I have very little experience preserving and canning. I would love to get your input!!

updated by @daniel-herskovic: 04/10/15 16:30:31