This is a wonderful drink, the kind of thing that makes people change their mind about "weird" fermented stuff.  The original recipe I got from Wild Fermentation by Sandor Katz.  This is from memory but I made it a lot at one point in time, should be mostly accurate:

Sweet Potato Fly

Shred two sweet potatoes and rinse the starch from them in a wire basket in the sink.  When the water runs clear, put them in a one gallon glass jar.

Dissolve 2 cups of sugar (I used honey sometimes in varying proportions) in some fairly hot water.  Add a pinch each of ground cinnamon, clove, ginger, allspice, or similar spice, any combination, any amount and add this mixture to the jar.  Fill the rest of the jar with water.  Can add half a lemon too if you want, but I've made it without and it's still good.

The directions in Wild Fermentation instruct to crush an egg shell up and add it to the jar (can add whey also if you have some), but I liked to re-use the fermented potato slop for muffins, and picking out the egg shell was a pain (and crunchy muffins were weird).  Adding the fairly intact halves of an egg to the batch gives about the same effect but is easier to remove later.  This adds some calcium and makes the whole thing a bit less sour. 

Cover the jar with cloth and a rubber band, or if you really don't have any fruit flies in your house, a lid that isn't screwed on all the way.  Ferment for about five days to a week.  It'll be bubbly and smell really really yummy when it's ready.  I'd assume that eventually it'd turn alcoholic, so much longer than a week might not be a good idea.  The recipe says 3 days....but that's like, just barely fermented in my opinion.  Strain of the potato (and save it!  makes a wonderful base for muffins) and keep the liquid refrigerated.  Enjoy!  Kids love this stuff, if you can get them to try it.  Has a distinctive smell that children are not used to nowadays.  It's sweet, sour, bubbly, and spiced all at once. 

And, the other one I've made and enjoy is:

Rejuvalac

Sprout wheat berries, then cover with water for 48 hours.  Drain off the water and enjoy as a slightly sour, very refreshing beverage.  Can get one more soak out of the berries before they should be composted. 

Far fewer people will like this one.  To be perfectly honest, it sort of smells like dirty socks.     But it's good!  And good for ya! 

That sounds really good!  Do you add any yeast?  Do you put any kind of an airlock on the jar or just not put the lid on or loosely?

Sorry, I modified the recipe and added the lid requirements.  Needs to breathe, yes. 

No need to add yeast.  It's so sugary there should be no problem convincing a wild yeast colony to take up residence in the mixture.  The lactobaccilli that come along with the wild yeast give it the sour flavors. 

No airlock required, you don't let it ferment long enough for that.  I'm sure this would eventually make some kind of mead/wine.  You could strain it into a bottle at 5-7 days and put an airlock on that bottle if you wanted to develop the alcohol content.  But that's not the topic of this thread!   

Wild fermentation is an AWESOME book! I've had friends who made/recommended the sweet potato fly recipe. Gotta try it.

Dirty sock wheatberry juice? hmmm

I made a batch Sunday and it looks like it's doing well.  I think...  Will the liquid be cloudy? Or have I created a monster?  It does smell good though.  It looks like it's not bubbling so much so I think I will strain it out tomorrow. 

hm....did you rinse the potatoes in the beginning?  I've forgotten to do that before and it still works but the liquid is a little cloudy and it has a thicker texture.  As long as it smells like something you want to drink, it'll be fine.  Some batches are bubblier than others, for sure.

It turned out great!  Really good flavor.  It is cloudy and a little thick. I did rinse the potatoes but I used two of the biggest ones I could find.  Would that make any difference?  Now all I need is a recipe to use up all the sweet potato gratings.

Glad you like it!  I want to make it for the permaculture design course I'm currently attending! 

As for the muffins. 

What I did is mix in enough flour with the strained sweet potato slop to create a very thick sponge.  Let that ferment on the counter for a day or two, then stir in some sugar (if you want), an egg, baking soda, and a little more flour if the egg adds too much more moisture.  It should be very thick - not quite as thick as scone batter.  Scrape it off with two spoons into muffin tins, bake until they seem done at about 350.  Really good, a little different every time.  Very moist, almost cake-like but with a neato flavor. 

Thanks for the recipe Marina.  The muffins turned out well.  Any idea if the drink would work with regular potatoes?  And could a person add fruit?

I've never tried to change the recipe.  Regular ol spuds might be interesting...or boring.  The flavor of the sweet potato adds something that's really unique, I feel.  Fruit could be cool!  Go ahead and try it, is my motto with fermentation. 

I once fermented a winter squash in itself.  Cut out the top stem, left the body intact and scooped out the seeds.  Then filled the hollow with salt water, replaced the stem top lid, and waited.  It was soft and sour and reallllly interesting a week later.  I used it as the basis of a soup.....that only I would eat. 

Three jars of Fly (we had no one gallon jars so I made due with smaller ones) are now fermenting in the pantry!  Letcha know how my fellow permie students like it (or not). 

So this morning I'm serving the finished fly.  It's a bit thicker than I remember it being, especially one jar - can't even strain the potatoes from the fly!  I think there's a ratio of liquid to potato that dictates the final thickness? 

how about amazake?  made some once when I had some koji left over from a batch of miso.  good stuff.  probably more difficult to make than the sweet potato fly, which I intend to try, but useful as a sweetener or as a porridge or as a beverage.

it's a complicated enough preparation that I'll just give a link instead of repeating it here.  that recipe assumes you've got rice koji.  if you want to start from spores and rice, it'll take you a bit longer.

How'd the fly go over?  I served some to a few friends and got mixed reaction.  It does seem to get better as it ages in the frig.  Next time i make it I'll use smaller potatoes maybe that won't make it so thick?

Everyone who tried it said they loved it!  But some people wouldn't even try it....typical with all things fermented in my experience, our cultural taste buds have largely forgotten the flavors and smells of friendly microbes, unfortunately.  I seem to remember that keeping it in a sealed jar for a few days will increase the fizz.  Too long uncapped and the jar could explode from unreleased gases, though. 

I have a feeling that the thickness is related to the potato starch, so less potato would mean less starch, and a thinner end product.  I hope you try again and let us know!  I plan to make some for us here in a few days.

I've never tried out amazaki because of my lack of koji, but I'd love to make my own miso sometime.  Doesn't it take 5-7 years to fully "go good?"  Thanks for the link!

Just finished making two gallons of kimchee.  Good good stuff......in three weeks. 

marina phillips wrote:
I've never tried out amazaki because of my lack of koji, but I'd love to make my own miso sometime.  Doesn't it take 5-7 years to fully "go good?"  Thanks for the link!

Just finished making two gallons of kimchee.  Good good stuff......in three weeks. 

I think the fastest miso only takes a couple of weeks.  the stuff I like (and make) is pretty good after 18 months, and great after three years.  I've yet to leave it longer than that, but my batches are getting bigger, so I probably will soon.

try g.e.m. cultures for a miso kit.  I believe you can use the same spores for amazake that you would use for miso, though you would ideally use rice spores instead of bean spores.

kimchee is great.  never done it in a way even approaching traditional with the fish and all, but just throwing some root vegetables and peppers and garlic in with cabbage always gives us good results.

One more question about the fly.  I've got it in a glass jar in the fridge. How long will it keep?  Does it spoil?  I guess that's 2 questions.   

I like beet kvass too - super cleansing and a good tonic for the blood. Last time I used whole star anise pods in it - YUM!

I am getting ready to try fermented ginger ale.

Have always wanted to make the fly!

Goodshephrd:  I'm not sure how long it keeps.  I've drank it probably after ten days in the fridge and it seemed fine.  Seems like it would eventually spoil but it might take a long time. 

Beet kvass?  Never tried it but I want to!  How's that made, Kristen? 

marina phillips wrote:

Beet kvass?  Never tried it but I want to!  How's that made, Kristen? 

The recipe is in Nourishing Traditions - it is just organic beets, whey, Celtic sea salt and filtered water. I can get the recipe if you want.

I had some made a few years ago by an Amish farmer that was much thicker and more effervescent than mine usually gets - it was yummy!

I have that book, I'll look it up.  Have some beets I need to use.   

Update:
Made some last night.   Gorgeous color!  Needs another 24 hours on the shelf by the stove.  Don't have any whey, used some mostly sour kim chee juice for inoculation. 

Update on the beet kvass attempt after three days of fermentation:

It was kinda sour and beety tasting and looks deliciously like blood, BUT!  Too salty to drink!    I poured that batch in the pot that will begin boiling a beef knuckle bone tonight.  Rewatered the rest of the beets for the second steep, but I'm afraid to add more salt. 

I poured off about a quart and a third of kvass, must've slightly under-estimated the size of my pot, hence the overly saline mix. 

Do you think I can get away with adding no more salt?  Sally's recipe calls for a full tablespoon of salt for a batch made in a two quart jar.  Could I just halve this amount of salt in the beginning, even though my batch isn't exactly half sized?  Or will I get beet wine? 

There were a few kinda cold days of its life in our cabin, does it need a consistently warmer temperature to be really sour in the three day time frame?  If so I might just wait til later in the year to try it again.  Dang, I was hoping to add this to my fasting liquid options. 

been making water kefir for the last few days.  great stuff.  fizzy and delicious.

I now have water kefir grains too!  Thanks to Jacqeline in Washington.  Might be the easiest and funnest ferment beverage I've tried. 

We fed ours some fresh made carrot juice day before yesterday.  It's separated and then remixed and separated again....Lots of bubbly activity. 

Anyone tried putting coconut milk in it?  Just curious....

I think one might have better luck with coconut water, or whatever you call the juice in the middle of young coconuts, than you would with coconut milk.  that stuff is crazy delicious.  dunno how it would be after the kefir treatment, but certainly worth a shot if you've got a couple coconut palms hanging around.

When making these lacto-fermented beverages, does one need to rack off the dregs? I made the Raspberry Drink from Nourishing Traditions, and it started out way too tart, but after a few days it has become wondrous. Just wondering if I should not be drinking the collecting dregs at the bottom. Thanks!

my guess is that the lees (don't know if that's the appropriate term in this instance) contain quite a bit of nutrition.  might not be the tastiest part, though.

folks often cook with the lees of alcoholic drinks, so you could try that, too.

I once made a fermented ginger drink where you add bread yeast & you have to open the bottles daily to let out a little pressure. It was very dry & fizzy, we added it to apple juice for the holidays.


Please share more about  this " water kefir " stuff it sounds fun.

Some people drink cider vinegar, often diluted with water and sometimes with honey.