Formaldehyde???

ocbrew · 05-05-2008, 05:32 AM

I have been having a common problem with my brews--they all smell and taste of fromaledyhde (that is the best description I can give)-- what is going on? I was concerned that I had been thinning things out a bit -- now I don't know. Did I get an infection?

saul · 05-05-2008, 08:08 AM

You might be over sparging, or sparging to hot. (should be between 70c and 75C)

**pjj2ba** · 05-05-2008, 06:25 PM

I wonder if what you might be smelling and tasting might be fusel alcohols. I can see how they might be confused with formaldehyde. Have these beers been fermented on the warmer side (over 68 F) and/or have these beers had fairly high starting gravities? Both of these conditions favor fusel alcohol production

The other possibility is acetaldehyde, but to me that is very different from formaldehyde

from the BJCP vocabulary site

Quote:

ac·et·al·de·hyde []
noun

colorless liquid with distinctive smell: a colorless volatile liquid with a pungent smell. Use: manufacture of acetic acid, acetic anhydride, and butanol.
Formula: C2H4O
In Beer: Acetaldehyde is perceived in both aroma and flavor as green apples, and in an oxidized state as acetic-cider. In the natural anaerobic fermentation process, Acetaldehyde is a precursor to ethanol:
Glucose → pyruvic acid → acetaldehyde → ethanol
Underdeveloped or young beer exhibits acetaldehyde wherein the yeast cannot reabsorb or finish the conversion process. The other version manifests from oxidation of ethanol or bacterial contamination, the cycle being:
ethanol → acetaldehyde → acetic acid

Brewers Control (how to change)
Cold storage for short durations promotes acetaldehyde in the final product, whereas longer cold storage would ultimately reduce acetaldehyde into ethanol — hence the cure.
Sources of...
Acetaldehyde is typically inappropriate in any style, though Budweiser has integrated it within their flavor profile with obvious success intentionally. Furthermore, Salvator & EKU-28 also display acetaldehyde, though in lower amounts.

**FlyingHorse** · 05-05-2008, 07:42 PM

Maybe this is what your picking up?

Quote:

Originally Posted by How to Brew

Medicinal
These flavors are often described as mediciney, Band-Aid™ like, or can be spicy like cloves. The cause are various phenols which are initially produced by the yeast. Chlorophenols result from the reaction of chlorine-based sanitizers (bleach) with phenol compounds and have very low taste thresholds. Rinsing with boiled water after sanitizing is the best way to prevent these flavors.

Most likely source would probably be chlorine/chloramines in your water supply, or bleach (if you happen to use that for sanitizing).

morrighu · 05-06-2008, 12:53 AM

I'd vote for 1) double checking your sanitation to make sure that its sufficient and that everything is getting really really really well rinsed and 2) filtering your water. Chlorine isn't just bad for your fish.

Our municipal water supply here tends to err on the side of caution meaning that if there's any doubt they add extra chlorine to everything. I approach showers with caution because of the amount of chlorine that they add. We got a whole house carbon filter that's pretty inexpensive. The canister was $20 a Lowe's and the carbon cartridges were under $10 for a six pack. It really makes a huge difference.

M.

ocbrew · 05-06-2008, 03:45 AM

I am very paranoid about my sanitizing however, I typically ferment around 72-74. I am thinking that along with oversparging at too high of a temperature frementing at that high of a number might be the problem. Will this flavor/smell dissapate as time goes forward.