[Steve L]

Hi all. Over my last 4 brew I've  been getting an unusual off flavor. It's been a a so
Me what tangy background flavor that has been in the majority of the last few brews in varying degrees. This is a recent problem that I have been blaming on lacto or wild yeast infections. At first I bought it was a particular yeast strain but that proved to not be the problem. There is one common denominator in all of the batches that I'm thinking May be the source of my problem. I've been adjusting my water for about the last 15 batches and had good results. Just recently, about the last 4 batches, I've started adding lactic acid to my sparge water.

This flavor is definitely evident immediately post fermentation, before bottling and increases once bottles are carbed. I do 2.5 gallon batches and in one particular batch I sparged with 3 gallons adding 1.2 ml of lactic according to bru'n water. This batch had the highest amount of this tangy off flavor. Could this amount of lactic acid be causing this flavor change? Could my lactic acid be old or bad? Thanks for any suggestions.

[ynotbrusum]

One easy way to tell - next batch sparge with RO or distilled and compare.

[dmtaylor]

It could indeed be the lactic acid.  Try without and see if the problem disappears.

Are you by any chance fermenting in plastic?  That could also be a source of permanent infection.  Replace all plastic and rubber components that come in contact with your wort and see if that helps.

[Steve L]

It could indeed be the lactic acid.  Try without and see if the problem disappears.

Are you by any chance fermenting in plastic?  That could also be a source of permanent infection.  Replace all plastic and rubber components that come in contact with your wort and see if that helps.

I think my first plan of attack will be the omission of the lactic. That's the cheapest idea.
I do ferment in better bottles. I usually soak them overnight with PBW after I empty them but it could possibly still be an infection. Would you replace any plastic upstream of the boil? I'd hate to think I had to replace my cooler mash tun... Ugh

[AmandaK]

I do 2.5 gallon batches and in one particular batch I sparged with 3 gallons adding 1.2 ml of lactic according to bru'n water. This batch had the highest amount of this tangy off flavor. Could this amount of lactic acid be causing this flavor change?

How are you arriving at 1.2mL of lactic with those volumes? Very high RA in your water? For reference, I'm using RO water, 10 gallon batches, with 0.5mL of lactic acid in the strike (12 total gallons) and 0.6-0.7mL in the sparge (7-9 gallons sparge).

[David Lester]

I had the same problem with Lactic Acid. It's kind of acrid and I think isn't a good fit for beer. Not sure why it's so popular. I started using Phosphoric acid, which is classified as a weak acid since it ionizes weakly in water. It is used primarily in soft drinks and quite a few brewers have started using it in beer by the prompting of a couple books on brewing. The part that makes it best for beer is that it doesn't add flavors to the beer like Lactic Acid.

As a note, it appears you are using too much acid. If you are adding acid, you should check it with a pH meter. Try to keep the brew water around 5.2-5.5 pH.

Good Luck, and Cheers,

[Stevie]

As dlester and Amanda noted, 1.5ml of lactic is a bit high for a 2.5 gallon batch. In theory it is below the taste threshold.

I, like Amanda, use about .5ml for lighter beers to get the ph to 5.5 and at most 1.5ml in saison to get the ph to 5.3. This is using all RO and 5.5 gallons in the fermenter.

Thought about switching to phosphoric, but I have a newish bottle of lactic and unfortunately inherited cheapness from my dad.

[Steve L]

My water at the time had a pretty high Alkalinity @ around 170. As far as the calculations, I use the sparge acidification in Bru'n water, input the alkalinity, and use that amount. My water source recently "dried up" so now I am just building from RO. Yesterday was my first batch doing this, an english brown. The Sparge acidification was almost none, it said I needed about .25 ml of lactic, so I'm curious as to how this batch turns out.

[David Lester]

swlusk, my RO water pH is typically 5.8, which I think is close enough not to have to add acid. I think this is pretty typical for RO. Check your pH, you may not have to add it.

Cheers,

[mabrungard]

170 ppm alkalinity as CaCO3 is fairly high. I'm not surprised that lactate may be tasted at that level. Another consideration is that the reported taste threshold for compounds is often the median or average value. Some tasters will be able to taste a compound at a much lower level. Maybe the OP is one of those individuals.

This is probably a case where other acids might be considered for this neutralization task. Dilution is another option. For the comment regarding the pH of RO water, pH is NOT a concern with brewing water. It is the alkalinity that is the concern. Brewers mistakenly use pH as the criterion for sparging water acidification, however it is really the alkalinity that needs to be considered. Even in Bru'n Water, the user sets a desired pH level in the sparge acidification page in order to end up with an acceptably low alkalinity...that is confusing, but it is what it is.

Depending upon the alkalinity of the raw water, the pH target you will need to set for sparge acidification may be well below 5.8. Conversely, if the alkalinity of the water is already low, it doesn't matter that the pH of that water is above the typical 5.2 to 5.6 mash pH range. That water's low alkalinity should not overwhelm the mash and its buffer system. So there is no need to acidify low alkalinity water like RO or distilled sources.

[Steve L]

Another question. I never PBW my cooler mash tun. I just rinse it out very well after each mash. Can you get a souring infection in the mash tun that makes it through the boil to the fermenter?

[mabrungard]

The only things that get cleaned and sanitized in my system are the plate chiller and the discharge tubing. Everything else is just cleaned of all debris and sprayed down. I never scrub or otherwise perform extensive cleaning and sanitization of my tun or kettle. Both have a nice tea-colored patina.

[dmtaylor]

Would you replace any plastic upstream of the boil? I'd hate to think I had to replace my cooler mash tun... Ugh

Sorry, I should have been more clear.  You only need to be concerned with soft materials after the boil.  Your mash tun is safe.

[mugwort]

One other thing to consider sanitizing is your kettle ball valve.  There's space in there that can harbor nasties.   If the valve is left fully open, you can find moisture behind the valve weeks later.

MoreBeer claims the heat of a boil does not sufficiently reach the valve to sanitize it and I believe them.

At MB's suggestion, I now boil a gallon or so of my strike water in my kettle and then drain through the valve at varying degrees of openness in order to steam-sanitize the entire interior area.

[morticaixavier]

The only things that get cleaned and sanitized in my system are the plate chiller and the discharge tubing. Everything else is just cleaned of all debris and sprayed down. I never scrub or otherwise perform extensive cleaning and sanitization of my tun or kettle. Both have a nice tea-colored patina.

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