Mysterious Off Flavor

Group W

Well-Known Member
Trial Member
Joined
Sep 9, 2017
Messages
1,314
Reaction score
2,208
Points
113
Location
Central Oregon
I thought this should be shared.

Been fighting an off flavor for the past year. My competition feedback on many brews cited the following: harsh, medical, phenolic, hop burn, etc. Not overwhelming, but just enough to keep me out of top honors. It was more noticeable in mild beers.

I worked on mash and sparge temps, PH, grain crush, sanitation and grain and hop freshness. Same, same.

I was at the LHBS talking about getting visible stuff in my HLT water. It looked like alge. The LHBS owner said maybe that was causing my off flavor.

I started researching off flavors from alge. Sure enough, there it was, astringent or phenolic.

My water is from a well with no treatment. I attach a food safe hose from an outside yard hydrant to plumbing inside my shop that runs up stairs to a utility sink. The water line feeding a water filter ahead of my HLT was black and slimy inside. The filter was a bit slimy inside also. I took everything apart, cleaned, replaced, etc. All hoses are now removed and allowed to drain and dry out. I even open the water filter, drain and rinse and soak the filter cartridge in starsan before standing to dry.

All is good now. What an ordeal. Cheers and happy brewing. :)
 
Last edited:
You don't have chlorine to worry about so I'd guess your infection was the cause. Glad you cleared it up!
 
Glad you sorted it out. Hope it takes you to the next level!
 
Wow! Who'd a thunk it? With the great water where you are that's the last thing I would have expected. You think the algae is growing in the white hose or later in the system?
 
Later in the system. I always drain the white hose and hang it to dry. The shop has pvc water pipe that gravity drains. Up stairs at the end of the pvc there is a splitter. One side goes to the sink, the other went to the filter via 5’ of 3/8” braided vinyl hose. That hose was the problem. It got enough oxygen to grow algae, and was small diameter and stayed moist inside.

Not having chlorinated water was one problem. Air exposure another. Wet lines another.
 
Glad to hear you got that all sorted.... that had to be a relief when you finally identified the problem. Here’s to you new and improved brewing!
 
Later in the system. I always drain the white hose and hang it to dry. The shop has pvc water pipe that gravity drains. Up stairs at the end of the pvc there is a splitter. One side goes to the sink, the other went to the filter via 5’ of 3/8” braided vinyl hose. That hose was the problem. It got enough oxygen to grow algae, and was small diameter and stayed moist inside.

Not having chlorinated water was one problem. Air exposure another. Wet lines another.
You're probably right: One instance where chlorine in the water would be a good thing!
 
.
I even open the water filter, drain and rinse and soak the filter cartridge in starsan before standing to dry.
Why wouldn't you just replace the filter cartridge with a new one? If you don't replace it at the recommended interval (based on the number of gallons you run through it) you're likely to have water-fault problems even with municipal water.
 
.
Why wouldn't you just replace the filter cartridge with a new one? If you don't replace it at the recommended interval (based on the number of gallons you run through it) you're likely to have water-fault problems even with municipal water.
The filters have a 3 month stated life. I’m either going to replace as suggested or remove the filter all together. Our water is outstanding and cold coming from a 550’ well. I will keep everyone posted and welcome any ideas or suggestions.
 
  • Like
Reactions: J A
Is this water you're using not boiled? If you boil the water, is there a compound in the water from the algae still present after the boil that causes off flavors?

The black slimy stuff inside your pipes is perfectly normal in non-chlorinated fresh water systems, in fact it's very helpful to have in copper pipes to prevent erosion of the copper.

I'm curious as to how you use this water and if there is something from the algae that makes it through the brewing process to cause the off flavors.
 
if you really want to be safe add a couple of drops of bleach to your strike water, stir then add some campden tablets to remove the bleach, I would test this out first by smelling and drinking it but it should remove any algae
 
if you really want to be safe add a couple of drops of bleach to your strike water, stir then add some campden tablets to remove the bleach, I would test this out first by smelling and drinking it but it should remove any algae
Wouldn't the water temperature itself kill the algae? Anything above 145F or so will pasteurize. The second thing is that algae is photosynthetic, it needs light to grow. Why would that be in the pipe or filter? I think the black stuff is a form of a common bacteria found in fresh water, wells, etc. Mostly harmless, especially if it's heated to 145F or higher.

It may not be the problem, the off flavors may have another source. Not sure what it is.
 
I agree on pasteurization, I would go to 180F myself but that does take time and extra 30 minutes for better beer is worth it
 
Is this water you're using not boiled? If you boil the water, is there a compound in the water from the algae still present after the boil that causes off flavors?

The black slimy stuff inside your pipes is perfectly normal in non-chlorinated fresh water systems, in fact it's very helpful to have in copper pipes to prevent erosion of the copper.

I'm curious as to how you use this water and if there is something from the algae that makes it through the brewing process to cause the off flavors.
Making beer, yes, everything going to the fermenter is boiled. So, yes, the off flavor is present even after boiling. So it’s not a problem with organisms growing in the fermenter. My water system has never been a problem in the house. I suspect because air is never present ahead of the tap. I think I created a situation in the shop where airborne organisms were propagated. I will look for the info on-line that led me to the algae problem. Thanks.
 
The second thing is that algae is photosynthetic, it needs light to grow.
Correct HVM. I believe the problem started in a 5’ piece of reinforced clear vinyl hose near windows. The algae seemed to extend from there with time.
 
“Phenols
Phenols are another group of compounds that can throw off the taste of beer. There are only a few beers where the taste or smell of a medicinal, spicy, or clove-like factor can be considered desirable. For most beers, an over-abundance of these flavors is undesirable. This flavor is more easily brought out of wheat based beers and beers brewed with certain Belgian and English yeast types. Hence, the flavors can also be brought out by wild yeasts that also have this quality.

These flavors can also be enhanced by the presence of chlorine in brewing water. This is an important reason why it is suggested to use filtered tap water or natural spring water for brewing beer, since it is very difficult to truly ascertain what is in the tap water. Algae traces can also contribute more phenols to the beer through the water supply.”
 
I run my water through 2 very good whole house carbon filters right before the HLT then a campden tablet just in case, I sent that reading to ward labs so I can adjust from there
 
I run my water through 2 very good whole house carbon filters right before the HLT then a campden tablet just in case, I sent that reading to ward labs so I can adjust from there
Sounds good OMB. Especially getting ward labs report after the filters. I suspect your filters are charged all the time. Like a normal tap in your house or at a hose bib. My shop is not heated and it has been well below freezing out there for the past two weeks. That’s why I need to drain everything in the winter.
 

Back
Top