Fermenting Wild Raspberries

The wild raspberries are ripe!  We found them first at Northwest Branch Stream Valley Park and then in the woods, across the street from my daughter’s house in Sandy Spring!  I couldn’t resist.  I do not like picking berries in the fields — too many relapses of childhood memories growing up working in the heat in the sun in the field.  But foraging free berries in the woods for an hour?  Sign me up! there’s a trick to expediting this process.  Pick more than one berry at a time.  When the raspberries are ripe, they grow in bunches.  The thorns are all on the stems.  Grasp the bunch, gently, and pull with just your fingers.  The not-so-ripe-ones stay in place to finish ripening, the good ones are in your hand! You can pick them one by one, but this really doesn’t wreck too many berries.  I’m going to blend them all so I don’t really care, but if you want to save some for dessert, they’re still in good shape.

I managed quite a bagful in less than an hour.

Fermenting Wild Raspberries

But I really wanted to ferment these into vinegar.  A pie was out of the question.  Everyone is on a diet in my house, so I’ll just ferment them.  No argument from me.  More than the wild raspberries, I was after wild yeast.  Just like that ever so faint white dusting on really fresh grapes, wild yeasts are on raspberries, too!  With this many berries, I have surely gotten a good complement of yeast to ferment this lot. I’ve been reading Wild Fermentation and I really wanted to put some of the principles to work. Authentic sourdough breads are started from wild yeasts ever-present in the air. Not only can these yeasts create an amazing flavor they are also very well suited to fermenting because they’ve got the home playing field advantage. They’re resistant to local molds and other things that will cause problems in your fermenters.

After a quick trip in the Vitamix, I’ve got a great raw mash. Beer brewers will boil this, sterilize it and take full control of the microflora that is present in the mash by inoculating the mix with imported yeast strains. Sure this looks like I’m leaving it up to chance, but I’ll fortify the mash with a cup of simple syrup and an ounce of fresh vinegar from one of the other fermenters. The sugar will fend off mold. The vinegar will do two things: it will raise the acidity early in the process as a natural preservative while at the same time, it will introduce some familiar acetobacteria that I trust to guide this ferment in the right direction.

Fermenting Wild Raspberries is easy and nearly carefree.  I will update this page with my progress and someday some salad dressing recipes!

Update: Two weeks later.

I moved the must to a wide-mouthed jar right after the last picture was taken. Covered with a cloth, and left in the dark, vinegar production has started. One of the by-products of aceto-fermentation is a cellulose mat that floats on the surface of the fermenting liquid. This is called a mother.  Once the vinegar is done in this container, the mother can be reused to ferment other alcoholic liquids.