Sour Sour Sour!

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BroBride

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Berthoud, CO United States
Hi all! My husband has had bad luck twice now with batches of beer that are very, VERY sour.

Is there a particular thing that contributes to this? ie: sterilization technique, fermentation time, etc?

Or, can it be a combination of things?

Thanks for helping me out with a very newbie question!

Cheers!

:mug:
 
If they're "very very sour", then it's most certainly sanitation.

Get some 'Star San' no-rinse sanitizer. Everything and anything that comes into contact with cooled wort or beer should be sanitized with 5-star.
 
If it is light in color, serve it to beer snobs as a "Berliner Weisse"

Realistically, you and your husband should spend some time here and learn the possible causes of infection and effective ways to prevent it. I also wonder if the description is what you really mean. A very sour beer would be produced by a clean lactobacillus infection, which is something some people do on purpose for specific types of beer. It is certainly possible, but with out knowing more about your experience with tasting different beer styles, it's hard to be sure you don't really mean "bitter", or some other description that might point to another problem. In any case, a description of the recipe used will be very helpful.
 
Germey - great points! This beer is what I would call very sour, however. Although it doesn't taste like a lemon, I can't only compare the sourness to biting into a raw lemon. It almost takes your breath away. :eek:

I'd expect bitter beer to do the same thing, however, this beer tastes like what a candy sour ball tastes like. I've had bitter beer, even tasted "bitters" that you cook with, and they're not similar to this batch.

It's only the final few swigs (where some sediment has fallen) that you can taste any of the what the beer truly should taste like.

I'll get the recipe of ingredients to you ASAP! :fro:
 
Yuri - distinct smell of vinegar, but tastes more like "sour" than "vinegar", however (whatever that particular difference may be!)

I would not equate the sour-ness with something that would go in a salad dressing... haha! It's more like the sensation of biting into a raw lemon.
 
Holy smokes...

Hearing that it could be a bacterial infection is a SCORE for me.

I'm a MICROBIOLOGIST (!) here in Colorado. I'll take home some culturettes tonight and work them up for bacteria.

Should I culture only the fluid part of the beer, the sediment in the bottom of the bottle, or mixed of both?

Wow... major learning experience for us all!
 
I don't know much about culturing bacteria, but I think acetobacter is aerobic. So, maybe try opening one, letting it go flat, then adding another teaspoon(ish) of sugar. Aerate it and let it sit with a bit of aluminum foil over the mouth of the bottle for a week. It might form "ropes" or a vinegar "mother" that you can further culture.
 
The only reason to let it go flat in the above "procedure" is to avoid excessive foaming when adding the sugar. Here's what I think will happen:

The acetobacter, in the presence of newly introduced O2, will finish converting any existing alcohol to acetic acid while the still present yeast convert new food (sugar) to alcohol, which, in turn, becomes acetobacter food. I guess you could skip the sugar step and just add a little vodka. Anyway, the purpose is to get a really nice ropey/slimy acetobacter mother with which to play microbiologist.
 
VERY interesting. I'll not only find out what ingredients are being used, but open one up and let it sit.

Thanks so very much! You describe a "mother"... is that the mother of infection?
 
In vinegar making, the slimy mass of bacteria at the bottom of the jar is called a "mother."

When you open the bottle, pour a little out, then shake it up a lot. The acetobacter need O2. Cover it loosely with a piece of foil to keep out most other bacteria and yeast.
 
OK Yuri - if I hear what you are saying, you suggest opening a bottle (if it wasn't flat already, let it go flat) add a tsp or so of sugar (or vodka) and sit covered for a week.

The yeast thats still there will convert the sugar to alcohol that the acetobacter will use up. The acetobacter will then turn into a slimy mother that I culture.

...now that was fun to say...

What temperature should this open bottle be left at? Room temp?
 
This is all completely guesswork (slightly educated) on my part. Since the acetobacter seem to have already taken hold at room temp, keep it at room temp.
 
I don't know, from her descriptions of the sourness, it sounds more like lactic sourness than acetic. Acetic sourness is a very hard sourness, definitely salad-dressing-y, whereas lactic is more super-tart. Also, to completely turn to vinegar, you'd need a lot of oxygenation (eg completely open to the air for extended time) because they're strictly aerobic. It seems more likely to be a strong lacto or pedio infection, both of which work anaerobically on sugars and dextrines to make lactic acid.
 
You're welcome.

By the way

to eliminate the infection: throw out and replace all plastic/rubber equipment. Sanitize glass and metal equipment with a bleach solution. There's a chance it's resident in your house, so on further batches never ever leave the cooled wort in the open air after the boil, and use star san to sanitise the bejeezus out of anything that touches the wort. Pitch sufficient yeast as soon as the temperature of the wort is below 75˚.
 
...lactic is more super-tart. Also, to completely turn to vinegar, you'd need a lot of oxygenation (eg completely open to the air for extended time) because they're strictly aerobic. It seems more likely to be a strong lacto or pedio infection, both of which work anaerobically on sugars and dextrines to make lactic acid.

Kai - super tart is a good description. Are you saying the strictly aerobic bacteria are the lacto's or pedio's or the acetobacter?

You're thinking anaerobes due to the fact that the beer is flat?
 
to eliminate the infection: throw out and replace all plastic/rubber equipment.

Thought that might be a problem. Gonna have to spend more money, I guess!

Pitch sufficient yeast as soon as the temperature of the wort is below 75˚.

I have access to an autoclave, has anyone every had success with this sterilization method?
 
Thought that might be a problem. Gonna have to spend more money, I guess!



I have access to an autoclave, has anyone every had success with this sterilization method?

An autoclave would obviously be very effective, but unless it it next to where you are brewing, it will be of limited value. 98% of us get by just fine without one. Your sterile technique and GLP training will serve you well as you watch the process. It may be, as Kai said, something in your equipment. In that case, it is up to you decide where the balance lies between money, labor, and risk of re-infection. If it's something in the environment, well, you can find a solution somewhere here on the board for just about any specific technical challenge. Do you brew with hubby? Just treat it like a very large scale inoculation of growth medium with a single organism. :p
 
Starsan is your friend. Soak for 30 seconds, and as long as the surface is wet, you're sanitized.

It's hard to beat that.

Got a 32oz bottle the other day for like 11 bucks. That's enough for over 150 gallons of sanitizer!
 
When I read the description, I also guessed lacto or pedio infection. It's possible to be acetobacter, but unless there was no airlock, I think lacto. Lactic acid is sour, but not really vinegar-y.

All tubing and plastic equipment should be replaced. Also, do you make sourdough breads or anything with wild yeast? It definitely sounds like contamination.
 
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