Fermented Garlic (Black Garlic)

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Picture of Fermented Garlic (Black Garlic)
I was introduced to "Black Gold" a few years back while I was cooking in Aspen Colorado.  It was brought into me by a vendor as a free sample and a new product.  Since that day, I have been determined to re-create the process for making black garlic. It took about 6 months of trial and error, but the final results were better than I hoped for.  The purpose of this Instructable is to give a very clear and clean cut process to making black garlic, this process was on my mind and there were tiny bits of information on the internet that dabbled in the process but none of them gave me clear directions.

Step 1: The Magic Fermenting Box

Picture of The Magic Fermenting Box
The most important piece of equipment that you will need is a fermenting box.  This little, or large, box will allow the garlic to sit at a consistent temperature for the allotted time.  I found that a wine cooler works the best because it is insulated, therefore it will hold the heat very well.  For the fan, I actually had an old hood unit from my stove that I replaced, so I kept the housing that the fan sat in and just cut the metal down to fit it into the wine cooler.  I also kept the switches in-tact to be used to control the fan speed and whether I want the light on or not.  
I now have a fan and two switches to control the two elements that will regulate and circulate my heat.  The last item that is need is a thermostat, these will run anywhere from $80-$120, all depending on what type you get.  The thermostat that I used came from Johnson Controls and they can be purchased here, this device will turn the power on and off to the box based on temperature.
Now go find yourself a vessel to make the garlic in, a device to heat the box with, a thermostat, and based on the size of the box, you will need a fan.
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tirnanog335 months ago

Hi, can you tell me what kind of heating elements you used and what wattage.?

also the purpose of the large lamp.? thanks.

akulinary (author)  tirnanog335 months ago
The purpose of the lamp is to heat. Therefore there is no other heating element. I think the wattage is 100w heating lamp.
Jagstah3 years ago
Hi, I have been following your DIY blog since April and I thank you for publishing your process. My wife pointed out that there might be a health risk when using plastic wrap as the shell for the fermentation process. Do you think that moisture dripping down from the plastic wrap in a box heated to 140 degrees will pose a cancer risk? Perhaps it would be better/safer to use glass containers instead? Best Regards!
akulinary (author)  Jagstah3 years ago
Thank you for the comment, I have looked into the plastic issue and commercial plastic wrap has a different makeup than the plastic wrap you would get at the grocery store. I am currently looking into an alternative and actually adding a humidifier or a mister to the box so I do not need to wrap it. I will be starting that project after I finish my meat curing cabinet.
All of my research from the past 7 months has led me to the now obvious conclusion that what is needed to make aged black garlic is a typical baker's fermentation cabinet. In German we call this a "Gärschrank" and this machine allows operators to individually adjust temperature and humidity. For the life of me I cannot understand why anyone would want to patent a new machine and process for making black garlic when millions of existing bread machines can already do it. Hats off to you though, for making your own and publishing your results!!

These bakers cabinets cost a fortune.!

akulinary (author)  Jagstah3 years ago
Never new that these machines existed! Thanks for the info, I will look into getting one or figuring out how to make my own. I am certainly not trying to re-invent the wheel here, I am just cheap, my box uses very little electricity and is very efficient at what it does, and in all of my research on black garlic no machine ever came up. I think the guy who is monopolizing on black garlic did patent his machine or the process, not sure though.
For sure, those "Gärschränke" (<-- link to google pics) cost a lot of money new so it is probably worthwhile to DIY if not trying to sell the stuff commercially.

A group of Koreans named Duck, Han and Sung filed a patent for a machine in 2010 which you can see online here. Also check out the pdf file linked on that same page, which includes a sketch of a fermentation machine which I believe to be the machine shown here.

FWIW I did not know much about the fermentation process before getting interested in black garlic and I'm no pro baker but now I believe that someone is trying to trick us into thinking that there is some magical, secret process to making this stuff when in reality it is as simple as baking cupcakes for 3 weeks.
akulinary (author)  Jagstah3 years ago
Wow! great set of info here, the wording is strange but I am working on deciphering what they are saying, and yes it is an easy process, they just put blinders up for everyone to think it was magical.
It sounds like a native korean patent lawyer specializing in technical devices wrote that application, doesn't it? The patent describes "sealing the garlic in a vinyl pack" ... I wonder how healthy that is ;-)
akulinary (author)  Jagstah3 years ago
I am in the process of breaking down the study, but it makes me frustrated trying to put the words together, lol. The bags are an interesting thing, I have a vacuum chamber at work I could seal garlic in and try it. The vacuum bags are a reliable tool, as they can also be used for "Sous Vide" cooking, which means they can handle temperatures up to 250 degrees. They are also PVC free so there is no risk of any health risks that I know of. The only concern I have is the garlic not being able to breath, the vinyl may allow this to happen at a slower rate, therefore it will hold the humidity in. I also do not know the botulism flourish in anaerobic environments, so the whole sealing in a bag thing scares me.
Just cut a piece of glass to size over your fermentation tray. OR put a bowl of water on your element.
akulinary (author)  timbit19853 years ago
Great idea! I have started another project and will give it a try as soon as I am done.
MsJan Jagstah3 years ago
Glass is always the safest way to go. Always stay away from plastics. They do cause cancer. I wish these companies would start making things that are safer for humans.
akulinary (author)  Jagstah3 years ago
On the glass baking dish, I started my experiments with glass mason jars and I did not get a final product that I was happy with.  Another technique that I will try is with parchment paper.  I use that a lot when braising foods followed by foil and that will help keep moisture in.
What do you think about using some kind of pyrex dish with a lid made of the same material?
akulinary (author)  Jagstah3 years ago
I used mason jars previously, and i did not get the results that I was looking for.
What kind of results did you get with the mason jars exactly?
akulinary (author)  Jagstah3 years ago
Well for starters I stacked the garlic in the jars, which led to uneven heating, I also did not have the garlic on the middle shelf of my box which seemed to be a better spot to ferment at. I am willing to try the mason jars again, sitting on the middle shelf, and wrapped in foil. The only other reason that I went away from the jars was so I could produce a larger quantity.
I dig that. If you're going to be turning on the heat for so many days you ought to maximize your ROI !!

Here is a recent blog about a cook who claims he makes his black garlic in a consumer-grade dehydrator. What do you think about that (nonsense)? A dehydrator normally sucks the moisture out of food but does not ferment it. But maybe this person has a special trick?

After reading that blog I thought about using a dehydrator too but to get the required humidity for fermentation I would have to place moist garlic bulbs in mason jars or plastic-wrapped baking pans like you did in previous experiments.

But to do that I would need a larger dehydrator, such as the Excalibur or the new Sedona from Tribest.

akulinary (author)  Jagstah3 years ago
With the amount of garlic that is being used (a full dehydrators worth), it might create enough humidity to prevent it from getting too dry. plastic or a trash bag around the outside wouldn't be a bad idea to keep the humidity in, and after reading the previous study that you linked there are certain levels of humidity that they obtain for different periods of time. My process keeps a high humidity the whole 40 days, then I dehydrate. The study shows dehydration in steps while the fermentation is occurring over the 40 days.

I also think the wrapping the baking pan with foil first then with plastic might reduce any concerns that arise from using plastic, I just know that you wouldn't want to use plastic that contains PVC, which I think is excluded from most commercial plastic wraps.
Hey, thanks for the info and tips! Now I have to decide which dehydrator to get. My wife likes the Sedona. Have you seen it yet? I think for all practical purposes a dehydrator which can also ferment garlic in "sealed" containers is the way for us. A used "Gärschrank" costs at least twice as much and would take up much more space as well.

I'll let you know how my first batch comes out, at least 40 days from now !!
akulinary (author)  Jagstah3 years ago
Have not looked into dehydrators recently, I always drooled over excalibur, but mostly because it was the most reputable and expensive brand. I look forward to hearing about your progress and final product!
CoreyW15 months ago

An electrical safety correction:

White Wire = Neutral

Black Wire = Hot (phase)

pb4047 months ago

This proofing/fermentation box is pretty affordable


jscene7 months ago

I just loaded up my rice cooker with garlic. I found a recipe that calls for nine days in a rice cooker on the "keep warm" setting followed by a week on a drying rack. I can't wait to see how this works as my wife planted about 7#'s of garlic in the fall. I hope to be up to my eyeballs in black gold soon! I'm concerned that the hole in the top of the rice cooker may allow too much moisture out and that nine days isn't long enough, but there's only one way to find out!

akulinary (author)  jscene7 months ago
Can't wait to hear about it! You could try plugging the whole with something to help prevent moisture loss. Maybe a little electrical tape to cover the whole? Good Luck and let me know how it works out!

jscene akulinary7 months ago

Will do Adam. I decided to leave the hole open and see what happens since this is my first time. I've read cautionary tales about too much moisture and not enough moisture... so we'll see! I also decided to put a head of elephant garlic in just for grins. Stay tuned!

troy.borrero8 months ago

I just finished my fermenter...well multi use project box....I got digital tempature controller from eBay for $15, wall outlet, appliance plug, small box from hardware store..wired the controller to one of the outlets so now I can plug a crock pot into it then cut the box so everything fit. Later I can use the same box for incubator, dehydrator, fermenter. I wired the other outlet for constant power so I can use it for a fan. the wiring was the hardest part for me. But it's holding 140F nicely!

so after fermenting for 15 days I gave garlic flavored rocks....bust...a lot of moisture inside the croc pot but still dehydrated very hard garlic..I added a glass of water today to get them to rehydrate maybe...they are black though

akulinary (author)  troy.borrero8 months ago

yea it sounds like it just got too dry, thats what i experienced my first few attempts. You want the garlic to keep most of its moisture for the first 30 days or so. After you get the nice color from aging aging around 35-40 days then you dry it out for 2-3 days to get the intense color and nice paste like texture. Mason jars did not work well for me but a baking dish with plastic and foil did. Someone else mentioned parchment paper, may work but still very porous.

When I started I put a damp towel on top of them (it was still damp) the lid had tons of water drops on it and wrapped the lid in plastic wrap to keep it sealed...even the sides of the cloves were damp...but inside was a slightly shriveled black cloves that were hard as rocks.

rainbowsly789 months ago
What about using a convection oven even the small toaster convection oven. it Has the fan the heat and the temp gauge?
akulinary (author)  rainbowsly788 months ago

its possible as long as the garlic is protected from the moving air.

PatO110 months ago

In Japan, people are using rice cookers to make this. I'm not sure what the temperature is. They are saying about 60 degrees C, but the garlic is black and very nice smelling in about ten days. You load the rice cooker with garlic, set it on "keep warm" and open it up once a day to rearrange the garlic. It comes out fairly moist, so it may need subsequent drying in order to preserve it. We are experimenting with this.

hi you,i'm student of university in
vietnamese, i really like product garlic, i dont understand about their
mechanism, why did white garlic became black garlic?, i want understand
it, i hope you can help me, please. thank you very much!

i learn english very bad. ^.^

Nedalice1 year ago

Do you think if I put it under the aquarium hood would work?

Hi, Are you using a humidifier or a mister to the box, and how does it works? waiting for further information..
akulinary (author)  black garlic2 years ago
No humidifier in this box, I let the garlic create its own humidity when wrapped up in the baking pan. The humidity should stay pretty high until you need to dry the garlic so a bowl of water would work fine if you do not have a humidifier.
thanks for your reply, I have already made it.
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