Oxidized Beer?

[smyrnaquince]

I have been battling an off taste in my beer since starting brewing. Always noticeable in my lighter beers, less so or non-existent in my darker beers (my assumption being that the heavier flavors hide the off flavor).

On Saturday, I brought home a growler of Harpoon Ale from the brewery. I opened it the next day and poured a glass--it tasted fine. I recapped the growler and put it back in the fridge.

I poured another glass the next day and, voila!, there was that off taste that I get in my own beers.

So now I am thinking that I am dealing with an oxidation problem in my beer and I am looking for help solving it. I have several areas that might contribute and I am wondering if any/all of these make sense as culprits:

• Too vigorous a boil
• Stirring too hard during chilling
• Too much headspace in fermenter
• Too long in fermenter

Too vigorous a boil
I boil off 0.9-1.0 gallon per hour from a bit over 4 gallons of wort on my electric stovetop with a pretty good rolling boil. Given the surface area of my pot (12 inch diameter), I'm wondering if I should cut the burner back to have less boil "churn"; I always leave it on full for the 60-90 minute boil.

Stirring too hard during chilling
I use a copper-coil immersion chiller and was given the advice to stir while chilling. I keep up a pretty good stir during the chill and am wondering if I am creating too much "churn" at the surface during the chill. It usually take me ~15 minutes to get it down to 68F.

Too much headspace in fermenter
I make half batches, typically 2.75-3.0 gallons into the fermenter. I am using a 4.5 gallon bucket and there is 4-5 inches of headspace between the top of the wort and the top of the bucket. Maybe the CO2 produced is not displacing all the air in the headspace?

Too long in fermenter
I typically let all my brews go 3 weeks in the fermenter. This may be giving too much time for the beer to start oxidizing. I'm thinking of cutting back to 1 week for lighter beers and 1 or 2 weeks for heavier beers. I don't secondary--they go into bottles after primary.

Ideas/comments? Thanks!

 

[Mx750ktm]

Im sorry I am no help really as I am fairly new here too. But I was curious if you could try to describe your off flavor? I seem to always have one too but I'm unsure what it is and figured maybe your description of how you feel your off flavor tastes might be able to lead me to the same conclusion of oxidation.

But on the same note here I would doubt what your doing with the chiller or boiling could be the issue only because I would assume your just aerating the wort which is what I have read countless times is what you want to do right after you pitch yeast anyways. Some people pitch yeast and shake the bucket or even use a device to help aerate the wort. So I wouldn't assume that would not be the problem. I'm not sure about the head space though?

 

[solbes]

From your possible causes, I don't see any of those really causing oxidation: A) Vigorous boils will not cause oxidation. B) Introducing oxygen into your wort while chilling can only help make good beer. The yeast will convert all of this oxygen early on in their reproduction (why some people put pure O2 into wort). C) too much headspace should only be a problem when you are past the vigorous primary fermentation. But if you don't remove the bucket lid until time of racking, I don't think this will cause a problem. Hopefully you also have a good seal on your bucket lid? D) 3 weeks is certainly not too long in primary, and I think you can only make things worse by going back to a week.

Oxidation really does start to taste like wet cardboard. I age beers and have tasted it. I've also had seriously oxidized wine which tasted like really bad sherry.

If these are not the off flavors you are experiencing, than I think I would look elsewhere. Really light beers like BMC, kolsch, blondes, cream ales, etc make it pretty easy to pick out off flavors since there is nothing to hide them. The hoppy beers and darker beers can cover up these flaws to some degree. Because of that, light beers are some of the most challenging to get just right.

Are you using pretty soft water with low alkalinity? Are you adjusting for high mash pH somehow (only really an issue with all grain brewing)? The lack of dark malts in light colored beers will leave the pH higher than desired. Any chlorine, iron, H2S, or other yucky stuff in your water?

 

[day_trippr]

I imagine a deficient bottling technique would be a fine way to introduce significant amounts of oxygen...

Cheers!

 

[BreezyBrew]

Do you bottle or keg?

 

[smyrnaquince]

I started using Bru'nwater to adjust my water (pH, Ca, and SO4), based on a comprehensive water report from the town that lists all the minerals, etc., on a per-well basis. (My town has multiple wells.)

I bottle. Usually 12-ounce with crown caps, but some 500-ml swingtops. No difference in taste. I have a spout in the bottom of the fermenter and run the fermented wort through a hose into the bottom of the bottling bucket, to which I have added the sugar dissolved in water. I stir the bucket once it is full to ensure that the sugar is mixed in. I use a bottling wand. I had been filling all the bottles, laying a cap on each one, then going back to fix the cap. Lately I have been doing the full capping on each bottle before moving to the next.

 

[solbes]

Any chloramines put into your well water? Those are very difficult to remove. Chlorine can be removed by letting the water sit out overnight, or by adding Camden. If you have a grocery store nearby that has an Reverse Osmosis system, I would try a batch with 100% RO and build the minerals back up to what Bru'nwater specifies.

Unless you are tasting a wet cardboard, or sherry taste as your off flavor. I don't see anything in your bottling technique that would introduce oxygen.

My only other advice is to make sure you throughly take apart and clean both the spigot on the fermentor and bottling bucket as they can be hard to get complelty clean. Small infections can often give a slightly sour taste to the beer (I've had it on occasion).

 

[blanstuf]

I'm very very far from even being considered experienced (15 batches or so total) but from your original post, what came to my mind would be hot-side aeration (which may or may not actually exist) when you're chilling. If you're stirring hard enough to be putting air into your wort and creating bubbles, I would think this could cause oxidation if HSA actually exists (see first link below).

Here are a couple links for research purposes.
https://www.homebrewtalk.com/wiki/index.php/HSA

http://www.howtobrew.com/section4/chapter21-2.html

 

[Conman13]

I would bet dollars to donuts that it's something in your process after primary has completed that is the issue, if oxidation truly is the cause.

Oxygenation before primary fermentation begins is a GOOD thing that you should not worry about. Yeast need a healthy amount of oxygen.

I would look hard at your racking and bottling practices. You want to make sure no splashing occurs to the beer after primary fermentation has ended, also that no oxygen bubbles are sneaking in to your racking tubes where the cane connects. Make sure when you transfer to the bottling bucket that you aren't splashing. Also, when you stir the priming sugar in, make sure you do it very gently so as to not splash at all.

You aren't trying to filter before bottling are you?

 

[smyrnaquince]

I plan to brew on Saturday and will try to be careful on all the points mentioned. Thanks!

 

[Hopper5000]

Are you secondarying at all? Plastic buckets can have poor lid sealing capabilities and generally aren't good for secondarying. This could be an issue if you are leaving your beer in primary for too long but it doesn't seem like that is an issue. Oxygen is probably getting introduced through the bottling process. Do you cover the bucket when you are bottling or stir in the sugar too vigorously. Splashing in the bottle while bottling can be a reason for introducing in oxygen as well.