Off Flavor in my stouts

ive brewed 2 stouts. both have had a sour/acidic taste. 1 was a dumper bc of it.
my most recent recipe is this:

8 Gallon Batch (extract)
Steep grains in 4 gallons of water. then bring 9 gallons up to a boil. add half of the extract. add 2nd half with 20 minutes left along with sugar.

- 15 lbs of Dark LME
- 1.5 lbs of brown sugar
1 lb of Chocolate malt
1/2 lb of Roasted Barley
1/2 lb of Black Patent

- 1.5 oz Magnum 60 min
- 1 oz Kent Golding 15 min
- 1 oz Kent Golding 5 min

S-05. ferm temps around 70 for 3 weeks. its been 4 weeks in the bottle. came out to 8%. SG 1.080 and FG 1.015

i put 4 gallons with cold steeped coffee and is nice. 1 gallon with cocoa nibs soaked and is nice and 3 gallons of regular stout and it has the harsh taste.

too much Black patent in there? (hidden by the coffee and choco)
none of my other beers have ever had this taste. i can only attribute to the black patent. my brown ale is a similar recipe - both chocolate malt and a little roasted barley. just smaller % without the black patent

 

Without knowing specifics I would say look at your water. roasted malts are acidic, so if your water is not hard enough to buffer those acids then the finished product could do that, another cause is bacteria, but if your other beer comes out fine then that is probably not it. There are salts, like Calcium Choride, people use as buffers.

 

i never thought about water b/c i use bottle water always. the well water is extremely hard and figured it would be no good for brewing.
maybe my next batch with roasted malts i will put a few liters of the well water to see what that does

 

I have hard water and, after carbon filtering, use about 50% distilled.

Do you have a way to measure PH?

 

Your fermentation temperature was around 70° for three weeks. Did you use heat to hold the wort temperature at 70° or was that the ambient air temperature? If that was the ambient air temperature, the wort temperature was a lot higher than that. Result harsh fusel alcohols. SA-05 works best at 62° to 64°.

An 8% stout is a big beer. Big beers need more time for bottle conditioning than an average 1.042 beer. Give the your stout 6 to 8 weeks for flavor development.

My palate would tell me to use only 4 ounces of black patent. That is just a personal preference of mine considering the lingering flavor of black patent in my mouth.

 

I'd definitely give it some time to age. I still have a few of my first Oatmeal stouts I made and they are a lot better after a year and a half. I can't help much with the PH because I'm still learning about it.

The one thing that makes me wonder is how long did you cold steep the coffee. I tried it twice and the first time I didn't have time to bottle . I left it steep for over 48 hours and it was horrible. I still can remember how it tasted. I dumped the coffee and started over. 24 hours was about perfect.

You need to get that temperature lower. I don't have a dedicated fermentation chamber but I use different places around my house to keep the temps lower. In the summer I use my cellar which it almost to cold. I have a water storage room which stays pretty cool because of the thermal mass of water in it. If I was you, I'd look into swamp coolers.

 

air temp in the house averages 75 at night and 82 during the day. i have a cooler bag, (cool-brewing.com) and rotate out frozen water jugs. i'm on that pretty hard. my process is:
day 1-10 rotating bottles 3 times a day, thermometer usually reads 65-68
days 11-18 rotate bottles in the morning and night. 70-72.
and the last few days i let sit at room temp. 75-80
i dont have issues with off flavors on my IPA, brown and Amber. the Stout is the thorn in my side right now.

my wife made the coffee. shes got the cold brew thing down. it was a light roast, steeped overnight.
the chocolate nibs were soaked in vodka for 4 days.

i dont have any pH strips or water testing kits. so ill either stay away from stouts until i get my hands on some, or give a small gallon test batch with a mixture of well water and bottled water.
im reading up on water. wow thats a whole new learning curve.

 

pH doesn't realy matter for extract brewing the lme is already pH balanced and has minerals added to it. All you are doing with extract is diluting and pre mashed concentrated wort, steeping a few pounds of specialty malts doesn't need any mineral or pH adjustments. If you where doing an all grain batch then I would be concerned with the pH. Have you made this recipe in the past? Maybe try cutting out the brown sugar and replacing it with some dme I have found that some times adding sugar can give a twang. I find beer yeast like eating malt sugars a lot better then regular sugar.

 

Will the sugar twang mellow out with time?

 

To help you out I tried an experiment. I opened one of my Dry Irish Stouts. OG 1.042 FG 1.013. ABV 4.2%. Was in the bottle for four days at 68°. Chilled it outside for a few hours at about 12°F.

It was terrible. Mouth coating syrupy, bitter, and acrid. Did I make a mistake, especially have 10 more gallons fermenting? No. I give the Dry Irish Stout a minimum of 4 weeks for bottle conditioning. It is one of my favorite brews.

Given yours is 8%, it probably just needs more time.

 

sugar twang will mellow with time. ive only noticed it with my apple ciders since both apple juice and sugar are both highly fermentable.

i havent had an issue with table sugar in beers. the only extract i have found here is an Dark/Amber extract that is a bit sweet. i dry it out with 1lb of table sugar per 5 gallon batch. if it is a lower gravity beer ill only use a 1/2 lb. this was an 8 gallon batch and imperial so i went with 1.5lbs. the body was a little thin and i like my stouts with a thicker mouthfeel so ill drop that by .5 - .75 lbs next time.

after going through my entire brew process, i think its a tannin produced from the dark malts, primarily the black patent. im wondering if my crusher grinds the malts to finely. ill loosen the setting next time.
time will tell, ill update in a month

 

I personally can't stand black patent after brewing a milk stout with it. When fresh it was acrid and tasted like an ash tray. After 6 months in bottles it earned me a gold medal in competition. Also, cold steeping highly kilned/roasted malts helps to extract the color without as many harsh flavor compounds.

 

I think it is your recipe. Swap the Dark LME out for Light LME and you should see better results.

Its good practice to never use dark LME. Its a mixture of base malt and some (unknown) amount of roasted malt. So in a sense, every ingredient in you recipe is a roasted malt. I don't think you have enough "base malt" (ie light extract) in the recipe. I made a recipe very similar to yours once and was not very happy with it.

 

When I first read the original question, I somehow glazed over the fact that it was extract and that you were not mashing. You can still do salt adjustments to water to change impression of the finished bear, Chlorides to bring out malt while sulfates enhance bitterness perception.
John Palmer says so