4th Brew. Questions on Low Efficiency, Very High Flocc Yeast, Diacetyl Rest

[BeerBanana]

Hey Everyone,

I did my fourth brew today. All grain, ESB. I have some questions? Can anyone shed any light on this?

- Efficiency was low. OG was 1.050 where it should have been 1.056 or thereabouts. Any ideas what could cause that? I brew in a Robobrew, mashed in at 69, mashed at 66, mashed out at 70, for an hour. I used 5kg of Marris Otter pale malt plus about 400g of specialty grain. I mashed with 16L (allowing for some dead space in Robobrew), and 16L of sparge water.

- I think I have probably picked the wrong strain of yeast but it's too late now. I went with WLP002, my recipe specified WY 1187 Ringwood Ale but my LHBS does not stock it, and this seemed to be the equivalent, also the Whitelabs website suggests WLP002 for an ESB strain. Probably should have gotten WLP005. I have never used "highly flocculating" yeast before, I noticed even in the start it tends to clump together extremely easily. I have an SS Brewtech Chronical fermenter. Any suggestions on how to keep the fermentation healthy and active? I've read to "rouse" it, but apart from giving the fermenter a gentle swirl each day I'm not sure how to do this. Is that enough to make a difference? I'm fermenting at 19 at the moment. I'd like for this to attenuate as much as possible.

- Do I need to do a diacetyl rest? Should I increase from 19 to 22 in a few days time?

Thanks heaps guys, got my fingers crossed.

Cheers

 

[A2HB]

Who crushed your grains, yourself or someone else? In my experience the leading cause of low gravity has been a poor grain crush. If someone else did it for you then that's probably the culprit. If you crushed yourself, next time you brew, double or even triple crush, and I bet you will get closer to or exceeding your expected gravity. It takes a few times of doing it to know what consistency to look for, and I bet whomever crushed your grains didn't break them down far enough to maximize sugar extraction. It's not a big deal just something you'll learn the more you homebrew. As for your yeast, you're fine, WLP002 is a great strain, it will produce a similar beer to the ringwood yeast, I wouldn't worry about that either. Finally for the diacetyl rest, I would wait until all active signs of fermentation have stopped, and then proceed with that step. Let your beer fully attenuate like you said and then you can start raising the temp, so that the yeasties can "clean up" after themselves (whatever that means). A good general rule of thumb is 2 weeks for active fermentation and diacetyl rest steps. I usually go shorter than that, but 2 weeks is a good amount of time to let it all start coming together. Good luck to you, even with the low O.G. you're still going to get a tasty beer, and it sounds like you have a great foundation to build upon.

 

[jmitchell3]

What a2hb said is standard and good advice. I'll give my slightly different nonstandard advice based on my own experience.

- 1a) crush may be a culprit as a2hb indicated. You can have your lhbs double crush. Do a visual inspection of the grain after crushing. Is there much flour or are the husks shredded? Then it may be fine enough crush. If there is not flour, whole husks, but you see whole kernels left, that's an indication that the crush is not fine enough. You want broken pieces, granules that are easily visible, whole husks, and little flour.
1b) also you indicated you mashed out at 70C. Normal mashout temp is about 76-77C. With my Blichmann breweasy system, a proper mashout gives me 1-2 more ppg in gravity.

- 2a) 002 is a very good yeast and I've had good luck with it. 005 is also very good, will attenuate a bit more, and flocculate well also. Either one would be fine for ESB. I did an ESB earlier this year with 005 and it turned out great.
2b) flocculation is a great character in yeast. However some flocculent yeast strains can drop out early, before you've gotten proper attenuation. (I've had this issue with s04 for instance). With highly flocculent English strains (and assuming you have temp control) I tend to start ferment low, say 17-18c, then I begin ramping temp after 50% attenuation (usually 2 days or so after the beginning of active fermentation). Ramp about 1-2C per day until ferment is done. The reason for this is two fold- it will help those flocculent yeast stay in solution and encourage full attenuation, and it will aid in clean up while the east are still relatively active. If you wait until active ferment is complete, especially with 002 or 005, a bulk of the yeast will have already flocculated and it will take much longer for cleanup to happen with the few yeast cells that are still in solution.
2c) finally...I recommend against ever rousing yeast. If needed pitch a second run of yeast (preferably at peak krausen in an active starter) to help fully attenuate and clean up.

- 3a) guess I answered the diacetyl rest question in 2!

Sounds like you've got a good fermentation setup with the chronically and temp control for being on batch 4! Good times...fermentation is where rubber meets the road in brewing.

Have a great weekend!

 

[jmitchell3]

Oh...the only thing I didn't mention that may help with efficiency...with all in one biab style systems, mash ph is critical to good mash conversion. If you haven't already I'd recommend spending the funds on a digital ph meter and a pro copy of bru'n water, or at least the free version of bru'n water or EZWater.

Don't overdo the mineral additions, and make up the difference in RA with a few ml of lactic acid (88%). Generally in my 5 gallon breweasy with 8-9 gallons of total water use, I need 2-5g gypsum and a lesser portion of calcium chloride and 1-5ml of lactic. My efficiencies went from mid 60s to mid 70s and my beer improved dramatically. Please note this recommendation only applies if you are starting with RO or distilled water...more complex calcs need to be done if you are using tap water.

 

[IslandLizard]

As @A2HB said, a too coarse of a crush is the usual culprit of low efficiency. Most LHBS mills are set very coarse, and some even coarser. You could mash 30' longer to give the wort and enzymes more chance to get at the deeper lying starches in the relatively large granules. But in the end, look for getting a finer crush. Milling 2x sometimes helps, but it would be best to narrow the gap. When small kernel grain (e.g., wheat, rye) is included the wide gap problem compounds significantly, as many of those kernels drop straight through, mostly uncrushed. So aside from poor efficiency, you'll be asking: "Where's the wheat?"

Be glad you could not get the Ringwood yeast. It's not very good tasting IMO, and it tends to stall halfway. WY1968/WLP002 is real ESB yeast, and like most of us, I love the results.

Keep the temps steady and raise a bit toward the end. It can be fast fermenting, and drop out like a brick, as soon as 2-3 days, so keep an eye on the dropping gravity, so you don't miss it. Taking samples should be easy with your conical.

Diacetyl is usually not a problem with this strain, but a little raising toward the end in that range is always good to keep it working and prevent it from dropping too early.