[redbeerman]

The last two beers I've brewed with S-05 have had a slight sour tang in the finish.  These batches have been ten gallons with five fermented with S-05 and five fermented with various lager yeasts.  The lagers have turned out very clean.

[majorvices]

I've used it literally a hundred times or more and never had that problem.

[deepsouth]

i've used it in two of my last three beers and i haven't had that problem. 

[utawana]

I'm thinking two things - astrigency or a mild to moderate wild yeast infection. The couple of times I've experienced "sour" notes from my pale ales are either from excessive sparges (astrigency) or if a local yeast sets up camp.  Did you sparge a lot or push the boundaries of sanitation in some way?

[redbeerman]

I'm thinking two things - astrigency or a mild to moderate wild yeast infection. The couple of times I've experienced "sour" notes from my pale ales are either from excessive sparges (astrigency) or if a local yeast sets up camp.  Did you sparge a lot or push the boundaries of sanitation in some way?

I've only noticed it with this yeast, split batches with a lager yeast for the other half, with no problems.  The beers were not very highly hopped.  I haven't noticed this with the IPAs I've made with S-05.

[a10t2]

I get that from US-05 every time. Whatever it is, the liquid Chico strains don't produce it (or at least, not enough that it's perceptible).

[utawana]

yeah that is pretty odd - if you fermented the 05 at a higher temp than the lager yeast batches, maybe that allowed for a wild yeast to propagate - the lager batches being too cold.
ehhhh, stab in the dark for sure.

[thomasbarnes]

I recently tasted a homebrewed Pils which had a similar problem. It's a sort of light lactic tang, but without the usual lactic thin body/gushing head. The brewer said that the beer had been stable with that flavor for months.

Not likely to be a wild yeast. They don't usually throw that sort of sour aroma.

I'm baffled as to what caused it. If you could get that sour taste consistently, it would be very nice for fruit beers or light summer beers.

[a10t2]

Not likely to be a wild yeast. They don't usually throw that sort of sour aroma.

I'm baffled as to what caused it.

It's definitely the US-05 that's causing it. There's just no way I had the same contaminant in that many (probably 80 or so) batches.

[thebigbaker]

With my limited brewing experience, I can't offer much explanation on why you are getting sour notes, but I can tell you I haven't had any sour issues with using 05.  I've only been brewing since Oct and have used 05 for 3 APAs, 2 IPAs, and 2 Milk Stouts and none of those had any "sour" issues.  It will be interesting to see what is contributing those sour notes w/ your 05 batches.

On a different note, I recently brewed one APA with 1056 (with the same recipe that I used for one of my previous APA) and my friends and I really couldn't tell any difference between 1056 and 05.   

[majorvices]

Not likely to be a wild yeast. They don't usually throw that sort of sour aroma.

I'm baffled as to what caused it.

It's definitely the US-05 that's causing it. There's just no way I had the same contaminant in that many (probably 80 or so) batches.

Even though I use WLP001 regularly I sometimes sub US-05 for my IPA and IIPA. I definitely think US-05 is a little "harsher" in character - not as smooth as 001 = but in no way is it "sour". I'll bring a bottle out to Seattle and let you decide if it is 001 or US-05. 

[a10t2]

Even though I use WLP001 regularly I sometimes sub US-05 for my IPA and IIPA. I definitely think US-05 is a little "harsher" in character - not as smooth as 001 = but in no way is it "sour". I'll bring a bottle out to Seattle and let you decide if it is 001 or US-05. 

I'll take that bet, Keith.

"Sour" isn't quite the right word. I usually describe it as "sharp". It fades to just a sort of musty unpleasantness over time. In a really hoppy beer it isn't really noticeable. But I've done triangle tests and can pick out the US-05 every time.

[majorvices]

I would say it has a more "dusty" character for lack of a better word. Not quite as clean, definitely not as noticeable in hoppy ales, as you say. "Mild yeast bite" is how I guess I would characterize it.

[thomasbarnes]

I would say it has a more "dusty" character for lack of a better word. Not quite as clean, definitely not as noticeable in hoppy ales, as you say. "Mild yeast bite" is how I guess I would characterize it.

I always think of "yeast bite" as being due to autolysis. Perhaps the yeasties are dying before they flocc out, or perhaps you just need to be really aggressive about racking off the trub once you get the clarity you want.

[Pinski]

Interesting, I recently did an APA with 05. 5 gal. dry hopped the other 5 gal. not.  There was definitely an unusual 'sharp note' in non-dry hopped keg that I've not tasted in previous batches with 05.