The Glow of Fall

Fall--in terms of colorful foliage--comes relatively late to north Georgia.  The peak color usually comes around the time of October 31-November 7 or so, with good viewing another week on either side of that interval.  Weather plays a role; if it's relatively dry and not windy, with good weather in late summer to set up a nice leaf-turning season, color can persist for as much as five weeks (in varying stages).

I don't know that I've ever adequately captured the almost luminous quality some fall foliage has--the right lighting can make it almost glow.  That seems lost in pictures.  The sassafras seedling at the top of the page is nice but not quite there.

Adverse weather can trash the fall leaf-viewing season; once leaves get to a certain point wind or rain will knock them down.  About three years ago, north Georgia got a dusting of snow in early November; it might be common up north but is a rarity here.  The snow came in on a strong cold front that had high winds, as well, bringing down the curtain on leaves for the year.

The specimen hickory is small and in my back yard.  It's showing pretty good fall color most years now.  For yellow color, hickory is my favorite.  Some maples turn yellow, too--sugar maples can be yellow, or orange (or a mix); Norway maples (which do not grow commonly or well here) are also predominantly yellow.

For reds, red oaks are the most striking to me, although sourwoods (shown above with the gold tassles) and black gums also turn a nice color.  Sweet gums can be anywhere from yellow to dark purple.  I have a purple seedling I'm going to transplant soon.

So what's the point of all this?  Not much.  It's just a nice time of the year.  It's beautiful, ephemeral, and sometimes fails to reach its potential--not unlike us.

Atmospheric Steam Canning

A few years ago I picked up a non-pressurized steam canner.  It was a model that's no longer made; initially, I was primarily interested in it because it was stainless steel and held eight quarts.  My graniteware canner held seven quarts, and when filled with enough water to cover quart jars, tended to gurgle water a bit.  I had to deal with boiling water bubbling up under the lid and out.  It wasn't the most fun to contend with.

The canner I got had a temperature gauge on the lid and instructions for steam canning, so I gave it a try and it was much easier.  At the time the National Center for Home Food Preservation (NCHFP) site warned against non-pressurized (or atmospheric) steam canning, saying they had been inadequately researched.  Still, for acidic foods it seemed to have potential.  The important thing needed for acidic food processing is to get the contents of the jars to boiling (actually, somewhat less than that is okay) for a few minutes.

Atmospheric steam canning is more convenient and quicker.  Less water needs to be heated, making the process faster and the canner lighter in weight than it is when water-filled, though the weight factor isn't as important as it might seem--it does not take much water to fill the canner up when a full load of jars is being processed, since the jars displace so much water themselves.

I tried a few loads with the steam process and noticed the jars in fluid things (e.g., pickles), was boiling when I took them out of the canner.  That suggested the steam got the jars to an adequate temperature. I processed most things a few extra minutes when steaming.  The canner also can be used for boiling water processing--though some steam canners cannot, since the lid fits on the body below the level of the top of the jars.

I then ran across a peer-reviewed study:  Paola Whitmore, et al., "Home processing of acid foods in atmospheric steam and boiling water canners." Food Production Trends 2015; 35(3):150-160. I had seen another article previously.  Essentially, Whitmore and colleagues put thermocouples in canners and in jars to measure temps with boiling water and steam processes.  The temperatures reached during processing both ways were essentially the same.  They included temperature graphs that show how slowly things cool off--which you have probably noticed if you have canned--and indicated that steam with equivalent processing times to boiling-water canning was fine.  The NCHFP now agrees, citing the Whitmore article.

Canning is probably not an area where a  lot of grant-funded research is being done these days, so this might be the only article on the subject for a while.  This process can't be used for low-acid foods, since they need pressurized steam (temps of 240 F) to kill botulism spores.  However, steam for acidic foods at normal pressure lightens the load a little when processing.