My beers are finishing with a big harsh bitterness

[m_c_zero]

My last few batches, I'd say at least last 3, have all finished with a big harsh bitterness, almost metallic, in the flavor. The batches have been varied: first was a porter, second was an IPA and third was a hefeweizen. I'm an extract brewer and have been following the same procedure for years and have never had this happen with so many of my beers. My sanitation procedure is on point and my equipment is basically the same that i've been using for some time now. The only thing different that I have done as of late is that I started using an oxygen stone. I've done it with other batches though that came out fine. I'm almost wondering if maybe I've got some bad Co2. Any ideas?

*EDIT* I also keg my beers, forgot to add that in there.

 

[Build]

Are you using an aluminum kettle? How fresh is your extract? Astringent? I've never known of bad C02 but you never know. How does it taste before you carbonate?

 

[GilaMinumBeer]

Maybe check to see if you have increased levels of sulfate in your water?

 

[Queequeg]

My thoughts turned to what too.

 

[GilaMinumBeer]

My thoughts turned to what too.

 

[kh54s10]

Two changes, should be easy to see if those 2 are the culprit. Oxygenate the next batch by shaking, and bottle at least some of them. If the kegged portion is bad, and the bottles are good, it is the co2. If both are bad it is something else because you didn't use the oxygen stone and still have the problem.

 

[javaking]

I agree with GilaMinumBeer, I would check your water. It would have to been something consistent between all batches. I recall John Palmer talking about how some mineral levels in water can bring out undesirable bitterness. It may be worth doing a test batch using purified water. Also a good note, if you are doing extract brewing it is also recommended to use distilled water as the extract contains minerals/water components that are concentration during the production of the malt extract (specifically liquid malt). Therefore, if you use water that already has high mineral levels you will be adding more into your wort which will give it some unwanted, almost metallic flavors.

Cheers

 

[m_c_zero]

Are you using an aluminum kettle? How fresh is your extract? Astringent? I've never known of bad C02 but you never know. How does it taste before you carbonate?

I am using an aluminum kettle to boil in but it's the same one I've used for years, just gently wash it out with dish soap prior to using it. Extract should be pretty fresh, I've been using liquid. If it is an astringency I don't know where it's coming from. Haven't done any tastings pre-kegging.

 

[m_c_zero]

Maybe check to see if you have increased levels of sulfate in your water?

I've been using bottled water. Distilled most of the time, sometimes plain old drinking water.

 

[m_c_zero]

Two changes, should be easy to see if those 2 are the culprit. Oxygenate the next batch by shaking, and bottle at least some of them. If the kegged portion is bad, and the bottles are good, it is the co2. If both are bad it is something else because you didn't use the oxygen stone and still have the problem.

Yeah, I'll need to do some more digging into it and perform some control samples.

 

[m_c_zero]

Only other thing I can think of is that I clean my beer lines with a PBW solution and then follow that up with a StarSan solution every time one of my kegs kicks. I feel like I run enough of the StarSan solution after the PBW that I get it thoroughly cleaned out but I'm wondering if maybe there's some solution left behind...

 

[Queequeg]

Autocorrect is evil