Diacetyl in IPA

[Cmross87]

IPA is one of my favorite styles but for some reason it's the only style I haven't been able to brew with good results except for one time. I'm not sure if it has to do with the water profile or fermentation but all the wasted money, time and effort is getting old. Here's the recipe I brewed:
13.5lbs Marris Otter
10.4oz carahell
1oz Falconer's flight 60min.
1oz cascade 30min.
1oz citra 30min.
1oz citra 5min.
Ferment with Safale US-05 66-68F two weeks. No secondary.
Dry hop 1oz citra 7 days
All my water is filtered. Mash is stabilized at 5.2ph. Also 2tsp gypsum added to mash

I've brewed this exact recipe at a different location and had much better results. Best IPA I've ever brewed. Every time I try to brew IPA again I get Diacetyl bombs. What the hell am I doing wrong?! It must be the water right? Any help is greatly appreciated. Cheers.

 

[V-Fib]

Maybe let it sit on the yeast longer. If you Google diacetyl, homebrew science they have a informative article about it.

 

[jcav]

You can try to raise the temp to 70-72 range for the last few days of fermentation for a Diacetyl rest. The yeast will then clean it up after a few days. This may help you out if you are having problems with that. If you pitched the yeast when the temp was too warm though you may have a more pronounced problem than if you pitched closer to fermentation temps. At least that is what I have read. If you pitched at 72 and then fermented down at 66 you have to raise the temp higher than 72 to get rid of the diacetyl like 74 degrees, according to what I have read. Hope this helps....

John

 

[Cmross87]

Thanks John. My pitch temp was 65 degrees. Most of fermentation was around 66-68 though the room my fermenter was in stays around 62-64 which the beer eventually dropped to so it makes sense that I would have leftover diacetyl.

 

[Redlantern]

US-05 can be very aggressive. Ambient may be 68, but fermenter is in the mid 70's with this stuff.

 

[Smellyglove]

What is different with your IPA's from your other beers, except for the hops of course?

Maybe you aren't starting your fermentation low enogh and/or don't have enough control of the temps?

Diacetyl is a yeast-problem. So it "shouldn't" just be your IPA's.. Might it be something you do or add when brewing IPA's which can make think it's D, when it actually can be something else?

 

[MVKTR2]

Diacetyl is produced in smaller qualities by all yeast during fermentation than is naturally produced via DMS production during the mash from all base malts, especially pilsner type malts. Boiling longerand/or stronger reduces DMS, the compound converted into diacetyl during fermentation, reducing the likelihood of diacetyl in the finished beer. Additionally yeast health is very important to eliminating diacetyl. After the yeast have an orgy of sugar eating they're generally tired. If enough healthy yeast don't remain after the orgy they are lazy and don't clean up after the party leaving a mess of compounds in your beer, including diacetyl.

Assuming Cmross87 is doing a 60 min boil I'd increase the ferocity of the boil a bit. FYI in home brewing pots with huge surface to volume ratios compared to commercial breweries most DMS is driven off in less than 30 mins. Insert Charlie Bamforth on beersmith podcast boil episode reference here. Thus your issue probably isn't boil derived. That leaves yeast health.

Looks like you're brewing quite the large/alcoholic IPA. We need your OG? For a 1.078 wort at 5.5 gallons you'd need 2 packs of dry yeast. Are you rehydrating with water per instructions? If not you'd technically need 3 packs yeast! Yikes! Another option is to brew a small beer then use that yeast cake to ferment your IPA. Yes fermentation temps/temp swings do impact diacetyl production but I'd look more closely at pitch rate and health as diacetyl is produced in all fermentations but healthy yeast clean it up.

Btw I'm guessing you're very sensitive to diacetyl.

 

[jfolks]

Sounds like a slight underpitch to me. Rehydrate 1.5-2 packets of dry yeast, or make a properly sized starter (check out mrmalty.com for confirming pitch rates and starter sizes). Ferm temps sound good, but definitely ramp up to 72-75 after the krausen falls. Those two suggestions should resolve any diacetyl problems given your process/recipe.

That being said, I think your recipe needs some tweaking to make a solid modern day IPA. 1 oz dry hop for 5 gal isn't even close to enough. 1 oz per gallon is a good rule of thumb the pros like stone etc use (and I can confirm that dry hopping rate is key for good homebrewed ipas). I would also shift the mid-boil additions to flameout and use more of them to compensate for lower IBU contribution. I like to target about a pound of hops for 5 gallons of IPA (but I add all of my boil hops at flameout as per the New England style, so west coast IPA might be closer to 12 oz). Also, make sure you mash super low - like 148.

Good luck!

 

[Cmross87]

Thanks for all the feedback everyone. I talked to the head brewer at my local brewery who home brewed for 20 plus years and he doesn't think I have a Diacetyl problem. Only in my IPA's I get a buttery or butterscotch like flavor. Maybe I just don't have healthy yeast? I've always read that if you rehydrate one pack of dry yeast it should be enough to ferment 5-6 gallons of wort which I've done before with this same recipe and had good results. Other IPA recipes with lower gravity have turned out buttery as well. Again I always rehydrate. Fermentation is steady and always reaches between 1.012-1.008 at 66-68 degrees. OG on the recipe I posted was 1.072 and finished at 1.010. I haven't been adding anything out of the ordinary to the mash or boil other than what I mentioned in the recipe. Next time I'll use White Labs and make a starter to rule out the yeast health problem