Sodium Metabisulfite

[Virginia_Ranger]

Having some issues with Sodium Metabisulfite... was in a rush and keg hopped with 0.27g of it in there as well and the beer has an apparent off sulfur taste and smell. Only been two days so I am wondering if others who have used it, will this fade. Can I make it fade faster? I am looking to package it (cans) tomorrow and hoping maybe time out of the kegs will calm it down.

 

[VikeMan]

Oxygen and/or certain metals in beer will clean up Hydrogen Sulfide (H2S, sulfur/egg odor). I don't think it really matters if it's in a keg or a can per se, but moving to from one to the other would introduce some more O2 (if needed).

 

[BrewMan13]

That's natural from the reaction that occurs. Kinda surprised it's noticeable with only that much. Purge the headspace a few times should help the aroma, don't know about the flavor.

 

[VikeMan]

That's natural from the reaction that occurs. Kinda surprised it's noticeable with only that much. Purge the headspace a few times should help the aroma, don't know about the flavor.

So, H2S is fairly volatile, and repeated purging (with ample time in between purges) would certainly reduce (but not eliminate) it over time. But the same thing would happen to volatile hop aroma compounds.

I'm assuming this is an IPA or other hoppy beer since OP mentioned keg hopping.

 

[Virginia_Ranger]

Yea NEIPA, which was fermented in a keg for low O2 and then transferred into fully purged keg (added hops and Sodium Metabisulfite by cracking lid wtih CO2 blowing).

 

[RPh_Guy]

Oxygen and/or certain metals in beer will clean up Hydrogen Sulfide

Specifically, copper and silver.

Kinda surprised it's noticeable with only that much.

The recognition threshold of hydrogen sulfide is only about 1-2 µg/L (parts per billion). The amount of SO2 added could theoretically produce as much as 4800 µg/L.

Having some issues with Sodium Metabisulfite... was in a rush and keg hopped with 0.27g of it in there as well and the beer has an apparent off sulfur taste and smell.

I recommend against adding SO2 at packaging for this very reason. The yeast convert it to H2S.

Lots of info about H2S here:
https://***************.com/wiki/Hydrogen_sulfide

 

[Virginia_Ranger]

Thanks, I was trying to help reduce any beer darkening with age on this style but am thinking it may not be worth it going forward.

 

[HopsAreGood]

@Virginia_Ranger Bit of an old thread I know, but how did this turn out for you? I have a similar situation going on.

I added .3 grams to my dry hop keg, transferred to my serving keg and it immediately stinks of rotten eggs.

Did the smell/taste ever fade away or disappear for you?

 

[TrainSafe]

H2S comes out of solution fairly easy at pH below the low 6’s. At normal beer pH, you should be able to depressurize the keg and purge a few times with good results.

 

[HopsAreGood]

H2S comes out of solution fairly easy at pH below the low 6’s. At normal beer pH, you should be able to depressurize the keg and purge a few times with good results.

Thanks. I’ll give this a try. I really don’t like purging the serving keg much because I feel like I lose a lot of the aromatics...but in this case I’d just be happy to get rid of the eggy smell. Lesson learned.