Personally I see no problem with subbing peaches for tomatillos as they are an acid fruit. Scientific studies have determined that in any salsa with 50% tomatillos or more, and with any combination of onions or chilies in the remaining mixture, the pH will be 4.2 or below, so clearly peaches being much higher acid than onions or chilies present no problem.

Since you're interested, there's a copy of the abstract linked at the bottom of the page.

I know of no single text for home food preservation per se. I used to have one link for a Canadian food study manual, but it's dead.

The issues cross disciplines including bacteriology and thermodynamics, among others. But the NCHFP does provide copies of some research on their site (including one on acidification of salsas) and that can be a good beginning. Also you might want to contact a regional land grand university with a strong food sciences program and check out their reading lists and recommendations.

Be sure you don't get to the point where you know just enough to be dangerous! There's a reason why a degree in the field takes years.

I think for most experienced canners it's a cumulative process of reading and study and asking questions. Even then we don't have access to the sophisticated testing facilities or resources of private corporations or universities and that limits what we can reasonably (and safely) do.

Carol

Here is a link that might be useful: Safety of Tomatillo Products Boiling Water Bath.

I'm sure that density DOES make a difference, I'm thinking that the thicker the longer the time needed to heat ALL the way thru.

Myself, I would not change things.

I'm thinking that pH would be the most important, density being second important. pH is tricky, whether in canning or planting.

I'm sure there is someone on here that will answer you in more detail.

I'm sure that density DOES make a difference, I'm thinking that the thicker the longer the time needed to heat ALL the way thru.

Myself, I would not change things.

I'm thinking that pH would be the most important, density being second important. pH is tricky, whether in canning or planting.

I'm sure there is someone on here that will answer you in more detail.

Just a general warning that "adapting" and "canning" don't necessarily go hand-in-hand as they often do in cooking. Sure there are some minor changes that are fine and the greater the understanding of the underlying science the more wiggle room there may or may not be.

But as a general principle, when canning foods, because of the storage environment that is created, one has to very carefully limit their spirit of adventure. :-)

And when experimenting you can't make the mistake of generalizing from one recipe to another. Each recipe and ingredient has to be evaluated on its own merits. So neither processing times nor % of a recipe are valid comparisons. As Carol said in this case it is the relative pH of the peaches compared to the other ingredients in the recipe that counts.

pH and density are of equal import in determining both the type of processing and the time of processing.

NCHFP does offer an online basic course you can sign up for. It doesn't teach all the theory details but there are certified classes available for more education in home food preservation.

Dave

Thanks, Carol, for the tomatillo reference. That is exactly the kind of article I am interested in reading.

And Dave, thanks for the reference to the NCHFP online training. I have requested the course and will give it a try.

I also noticed that they offer webinars. I will check those out as well.

Nancy