Slightly Sour Oatmeal Stout

[oceans11_gt]

So, I am about 7 batches in. Some have been great, others just OK. My current brew in bottles is the Midwest Supplies Oatmeal Stout kit that I brewed back in the beginning of Oct. The only addition I made was that I added a bit more chocolate malt (4oz) the last 10min of the boil. It say in the primary for a week and then in the secondary for another week and half. My Hydrometer was broken so I could not measure gravity but I made sure there was no activity before bottling. It has since been in the bottles for about a month and a week. There is minimal carbonation and has a slight sour taste. Not sure if its a tannic taste, astringent or what. Just tastes...well.... not as I expected. Smells excellent, looks great minus the minimal head from little carbonation, just tastes sour.

Im pretty anal when it comes to sanitation so I don't think its contaminated but then again I'm still a Newbie. Just figured contaminated beer would taste really bad and not able to be drank.

My only other thought is that I used 2 gal of distilled water as top off water before I read that distilled is not a good idea. Maybe its lacking minerals? the rest of the brew (3gal or so) was my normal tap water so maybe it's too soft?

I don't really want to dump it, but also don't want to wait more months to find out there's no change when I have an RIS that's could be bottled soon and I could avoid buying more bottles.

Thanks for your input!!

 

[Johnnyhitch1]

You say you added 4oz of chocolate malt at the end of the boil. Was this actual chocolate or malt itself?
Grains should never be boiled unless your doing a decotion mash (step mash by boiling part of the grist)
Boiling grains will cause astringency or puckering tannins. This might be what you are tasting perhaps?

You also said you toped with DW. This might lend more towards a "thin" body.

 

[oceans11_gt]

Grain malt. Yeah I thought it wasn't the greatest idea but it was a suggestion from someone and against my better judgement tried it. It is kind of "thin" for a stout anyway.

 

[pHBTa]

I was just working on an oatmeal stout kit today as well, and am having a similar problem of it tasting a bit sour -- more sour than I'd expect. But then again, what I've learned is that beer never quite taste like beer until it gets carbonated. In my case, it is awaiting a final racking and then priming and bottling. I am proceeding as normal until I am 100% sure it has off-fermented and is (proven) not safe for consumption.

I mixed up the kit ~3 weeks ago, and all went well, so I left it in the primary fermenter until today. There was semi-translucent white growth on the top, though I'm not too worried about that as I've had that before and I assumed it was the yeasts in the wort/must starting to build structures. The SG has been stable for over a week now at 1.020, which is just a bit higher than the 1.008-1.018 ("depending on product type") final gravity suggested in the instructions, which I am also not too worried about.

But now I'm wonder if perhaps I grew some sort of aerobic bacteria, and/or if there's something that slowed down fermentation and left the wort un-dominated by good yeasts, thereby allowing this in the first place?

Or maybe, and this is what I've been thinking the longer I sip at this cup of uncarbonated Oatmeal Stout, just maybe this is how it tastes prior to finishing. I mean, beer with carbonation is never tasty.

And then again, I've never tasted an oatmeal stout of any kind in my life. Is it a more sour stout?

And then I don't know what to make of the OP's problem, as I did not add any additional grains myself to mess things up.

Any words of advice?

 

[Joesl8]

I've been brewing for about a year now. I've been making mainly IPA but the last two chocolate oatmeal stouts have come out sour, or infected or ?? I got the recipe online, it had good reviews, it's under "double chocolate oatmeal stout" but the flavor is just sour, it takes forever to carbonate and it's just plain aweful. I know I'm not doing anything unusual, I sanitize like Howard Hughes, I use reverse osmosis bottle water, follow directions to a tee and used two packets of dry yeast. It fermented for about five days strong...any ideas or suggestions? Wonder if anyone can look at that recipe and tell me if it's bad...?

 

[Qhrumphf]

Well, dark grains like roasted barley or chocolate malt can contribute a fairly significant amount of acid. Some folks like to cold steep them separately (I know Gordon Strong is big on this method). I prefer to keep my mash pH on the higher end when using lots of roasted malts. As I take it you lot are brewing extract kits, mash pH is something you have no control over, so cold steeping your roast malts may be helpful to you.

 

[Joesl8]

Well, dark grains like roasted barley or chocolate malt can contribute a fairly significant amount of acid. Some folks like to cold steep them separately (I know Gordon Strong is big on this method). I prefer to keep my mash pH on the higher end when using lots of roasted malts. As I take it you lot are brewing extract kits, mash pH is something you have no control over, so cold steeping your roast malts may be helpful to you.

Thanks for the reply. I do all grain with everything together in the mash tun, 10 gal igloo. I mashed these at lower temps, 156-158. I put a tablespoon of baking soda in the mash last time. I let it mash for 90 min then boil for 1 hour. I haven't gotten scientist on my brews as of yet, I was wondering if my temps were wrong or if the ph was off but my buddies do pretty much the same thing? I've done black ipas with no prob either.