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Vinegar fermentation Introduction

I have more than 30 years of vinegar fermentation with 19 International awards. I have perfected the “static” process and am willing to offer my experience to those interested in making high quality vinegars from beer/ale, wine or various fruit juices.

I tried to make some vinegar from a spiced Porter. My method was to add some mother from an organic cider vinegar to my Porter. It turned to vinegar and it was alright but not very complex. I added the dregs of that to another beer which never really developed so I dumped it and gave up. I’ve had some very nice craft vinegars

Hi @Roger and welcome to the forum. Although I’ve never made vinegar I would be interested in hearing about it. It sounds like you have quite the experience and knowledge. I look forward to having this knowledge on hand!

It was good that the “mother” you got was still active. To get started, you’ll need a glass or plastic (food grade) container about 1 litre in volume. When I teach courses on this, the first thing I tell the students; You will end up with more vinegar than you can handle because we don’t drink vinegar like we do wine/beer. Keep it small.

The alcohol ratio to the batch (total volume) must not be more than 2%. To start; use an apple cider vinegar as the starting base. This will give you the acid environment that the acetobacter needs. You will also need an alcohol liquid such as beer or wine that is at least 7% alcohol/volume. Beer at 5% can be fortified to 7% by using whiskey, Rum etc. and the wine can be diluted with “Grape Juice”. I can offer the calculations if you want later. The beer or wine as food must be “approximately” 15% of the “total volume”.

Put the mother on top and cover so that air can get into the batch. Put it in a place away from direct sun light. The mother will then begin to grow on the surface and if the ratios are good and the mother is good, it will probably only take 5-6 days to convert the volume of the wine/beer to vinegar. Mark the side of the vessel so that you will know what the volume should be kept at. Be sure to not disturb the process. It relies on being “static”.

Remove the 15% of the "finished vinegar and seal it completely in a glass jar or plastic jar (food grade) and ensure it is sealed well with very little head space. Add more wine or beer (15%) and look at the level mark. You will notice that the level has dropped. You will need to add clean water to bring that level back up. You wont be diluting the vinegar. Just replacing the water that was lost.
Let know if this helps and don’t hesitate to contact me for more info if required.


When you say remove 15% finished vinegar you mean your pour off the top? Is this vinegar done or do you need to age it longer?

First, remove the mother with a slotted spoon. Scoop out the 15% food substrate (beer) that you put into it. This 15% volume is “finished vinegar”. Seal it tightly with little head space but leave a bit of room and allow the solids to settle out. This will also kill the acetobacter in the bottle. The Acetobacter is a strict aerobe (It need air to live). Allow at least 7-8 weeks. If you allow it to age it will get better. The apple cider vinegar that you started with will eventually be replaced with your beer. In the meantime, you will have a nice blend vinegar.

Once you have a balanced process, the system will be self reliant. There will always be enough bacteria (acetobacter) there to start up another batch. It is important to maintain the ratios. When you remove the “finished” vinegar and add the beer (substrate), the acid value will drop. I have calculated the ratios so that you wont have a problem with other unwanted guests in your batch. The the acid value when you start up again should be approximately 3-4% which is a safe value.

Eventually, you will have more acetobacter than required and will have to remove some of it. That; at a later date.

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My pleasure. When you and others get comfortable with the process, I will be able to attach (I hope) the paper that I have on this.

Does the beer need to be uncarbonated or does it matter?

It doesn’t matter. You may have to fortify the beer’s alcohol value if its only 5-6%. 7% is best 8% is better. I have always preferred dark rum for any fortifications but any hard liquor will do. The liquor that I use is 40% alcohol/vol. (Canada) Here is a calculation you can use;

Assume a 1 litre total volume (1000ml). Since we are now getting into calculations, I’m increasing the beer (substrate) volume to 200ml at 8% alcohol/vol. This means 800ml of vinegar base/culture + 200ml substrate (beer)

(200ml beer) (0.08) = 16 ml pure alcohol
16ml alcohol / 1000ml total volume = 1.6% alcohol to the total volume. This is a good value. Less than 2% but greater than 1%

Fortify 200ml beer that is 5% alcohol using 40% liquor to 8%:
(200ml)((0.08) / 0.4 - 0.08
= 16 / 0.32
= 50ml
Therefore add 50ml of liquior to the 200ml beer to get beer at 8% alcohol/vol.
Check: (50ml liuor)(0.40) = 20ml of pure alcohol
20ml alcohol / 250ml fortified beer = 0.08 (8%)

You will only be using 200ml of that fortified beer though. Save the rest.

As you can see, the finished vinegar volume will be 200ml. You must think of bottle size for storage. The bottle must be full (almost) and sealed tightly. You can put plastic wrap over the bottle top before sealing. Any hint of space and the culture will start to draw in air. This will maintain the growth of the culture which you don’t want.

Re-arrange the values of the vessel volume and substrate addition to get the correct volume of finished vinegar for the storage bottle. Basically, he storage bottle volume will dictate what size fermenting vessel you need. Let me know if I’ve made some errors in calculations or you need further assistance. Always willing to help

OK I rummaged around and found a bottle that’s just a tad under 200ml and I also have a 1qt Mason jar. I have a 8.9% Fig Porter( imperial) and about 2/3 organic apple vinegar w/mother. So I’ll put 200ml in the jar and pour the cider vinegar on top. What if it’s not enough vinegar to reach 1000ml ? Not heading to the store fore a couple days

Since you are just starting the process, you can add water to the Porter to bring it down to 8%.
Dilute 200ml at 8.9% to 8%
(200ml)(0.089) / 0.08 = 222.5ml
222.5ml - 200ml = 22.5ml water to add to the 200ml porter
(200ml)(0.089) / 222.5 = 0.08 (8%)I can offer more specific calculations to get the exact desire volume but you don’t need this right now.

On another point; It is beneficial to have a vessel that has a larger surface area like a square or larger circular 1 liter (1 quart Imperial) container. The mason jar will work but you want to strive for efficiency. The culture (acetobacter) will be at the surface of the vessel taking the free dissolved O2. they are motile (able to move about) and will go to where the O2 is and that is at the surface. When you get this batch going you may want to increase the vessel volume slightly with a larger surface area.

Put the vinegar into the jar and then add the prepared substrate (beer). Cover but be sure to allow air to get into the vessel. It doesn’t have to be a large opening. Just a few small holes. The acetobacter will start consuming the O2 and that will create a sort of vacuum in the vessel. It will then start to draw in the O2 that it needs. This is why the storage bottle must sealed tightly.

OK I had 600ml vinegar to which I added 180ml of 8.9% beer since the bottle i found is about 180ml. I used a 1gallon wide mouth vessel. Should I still add water?

You’re good with that because your just starting. If the mother is good you should see a new mother growth in about a day or so. If not let it go until you think the culture has taken hold and balanced. Since you’re not titrating for acid values, the substrate that you add should be converted to vinegar in about 6 days. Monitor the mother production. When the mother gets too big (over growth), the system will begin to shut down for 2 reasons. 1st; the mother actually hinders the O2 absorption at the surface an 2nd; There is a phase which most newbies don’t understand.

When the available alcohol is completely consumed by the acetobacter, they will start to consume the acetic acid that they have already produced. The end result is WATER. Your entire batch will be turned into water. This phase is called over oxidation (Alcohol is consumed to produce acetic acid and then to water). This is the natural process Alcohol - vinegar- water which is “complete” fermentation. For us, we stop the process before the 3rd phase (water). The balance and timing is everything. If after 6 days (using your volumes and ratios) you are in doubt as to whether or not the vinegar is “finished”, remove it regardless and re- seed with the substrate. My process was much larger (10 x 26.5 litre vessels). It took on average 10 - 12 days for completion. Your smaller vessel should only require 5-6 days when balanced. Your previous batches were probably good but may have been subjected to “over oxidation”

I’m curious how this would work starting with a sour beer. I have a kriek that’s really fruit forward, it might be worth sacrificing a bottle as an experiment. Since the pH is already low, maybe it could be done with less added vinegar.

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I have some fruit flavored sours as well might make a nice salad dressing

guess who came downstairs looking for her cider vinegar. " no dear havnt seen it must be out"

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Been there done it. On another note; I’m fully retired from this but remain teaching. My business name was “Mr. Vinegar”. If you Google it you may find some info even tough I took down my web site.

Once you get “balanced”, your vinegar making will entail many new forms of high quality vinegars. I made my own wine for the substrate and the best part was, it didn’t have to be finished/aged wine. The wine supplies the substrate ans the quality comes with the vinegar production and aging.

Check lout my replies to Brew-cat etc. If you need more info contact me.

I once stopped into a vinegar shop and I was doing shots of vinegar. Delicious. Thanks I hope this works better than my last attempt

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