Problems with my first all grain DIPA. What happened?

Discussion in 'Homebrewing' started by cpferris, Sep 1, 2014.

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  1. cpferris

    cpferris Zealot (512) Jan 22, 2008 Indiana
    Trader

    So I have 5 all grain batches under my belt...all IPA. I decided to take a shot at the Pliny recipe that has been floating around from Vinnie at RR. With the recipe, it expects OG to be at 1.072.

    From my previous batches, I have been getting around 60% efficiency. So I adjusted the grain bill up via BeerSmith and got it to where I could hit the target OG. This time, I decided to mash with 1.65qts/pound as I read Denny Conn has had alot of success with that. I batch sparge.

    For a 6gal batch, I normally have a preboil volume of 8.25g (as I lose about 2g to evap during the boild. Since this was a 90min boil, I decided to bump the preboil volume to 9g.

    My temp adjusted pre-boil gravity was 1.055. Considering I still had to add 12oz of corn sugar, I figured I'd be in business.

    The recipe said to stir in the sugar before you started the boil, so I did that. I completed my 90 min boil, cooled to 67F then checked my OG and only got 1.061. What happened?

    I last time I brewed I got 1.063 with no sugar and 1# less grain.

    It'll still be a good beer, but I have no idea what might have happened (especially considering my pre-boil gravity and I added sugar).

    Anyone help a brother out?
     
  2. VikeMan

    VikeMan Grand Pooh-Bah (3,067) Jul 12, 2009 Pennsylvania
    Pooh-Bah

    It sounds like you have a gravity measurement error somewhere.

    But just to know where to start looking... What was the volume of wort when you took the reading of 1.055?
    What was the volume of wort when you measured 1.061, including whatever wort was tied up in your hops?
     
  3. cpferris

    cpferris Zealot (512) Jan 22, 2008 Indiana
    Trader

    I recorded 1.039 @ 139F with 9 gallons before I added the sugar pre-boil. With temp adjust, beersmith says that is 1.055.

    This was the first time I used a hop bag in the boil I just left the bag in my wort as I cooled it then drained it to my primary. I drained 6g into the conical, then there was about 0.75g left in the boil pot after I wrenched out the hop bag liquid.
     
  4. VikeMan

    VikeMan Grand Pooh-Bah (3,067) Jul 12, 2009 Pennsylvania
    Pooh-Bah

    Sounds about right. So you would have had these total "Points" of gravity in your wort...
    9 gallons x 55 points per gallon = 495 points
    Now add another 34 points for your 12 ounces of sugar...
    495 points plus 34 points = 529 points total


    A post boil OG of 1.061 would mean your total post-boil wort volume must have been...
    529 Points / 61 Points per Gallon = 8.67 gallons

    So 6 gallons into the fermenter, plus .75 gallons in the kettle = 6.75 gallons accounted for...
    8.67 gallons total - 6.75 gallons accounted for = 1.92 gallons unaccounted for. That would equate to the absorption for about 2 lbs of leaf hops. Or a lot more pellet hops. I'd be curious about type and amount of boil hops.

    Assuming you didn't use that many hops, my guess would be that your first gravity reading (or the corresponding temperature measurement) was off, and that your mash efficiency was somewhat lower than what you were expecting. I suspect this first gravity reading, because it actually involved two significant measurements.

    Also, you may have had a little more wort left in the kettle than what you eyeballed to be about 0.75 gallons. This would also explain some missing sugars.
     
  5. koopa

    koopa Initiate (0) Apr 20, 2008 New Jersey

    On an 8.25 g (preboil) volume, you boil off 2 gallons in 60 minutes? That is 24% per hour and highly unlikely. My guess is that you have either added the 4% cooling shrinkage loss or some hop absorption loss or some of your transfer loss or A COMBO OF THOSE THINGS into that estimate. Your estimate of 2.75 gallons boiled off over 90 minutes is a bit more conservative (20% per hour) but still way too high. That being said, the extra volume you claim to be losing due to boil off (which would boost your gravity) is probably actually being lost in other ways that don't boost your gravity so ultimately that extra liquid contributes to your low gravity. If so, minimizing those losses will allow you to start with a smaller volume which should help increase your gravity.

    After all, you are claiming you start with 8.25g preboil, boil 2g off, and somehow get 6g into your fermenter.... That simply isn't possible. Say you did boil 2g off, that leaves you with 6.25g now subtract 4% cooling expansion loss and you are down to 6g. That means you are losing NO VOLUME to hop absorption, kettle dead space, trub, or transfer....

    Also, who is crushing your grain? Has it been consistent from batch to batch?


    To help you get your numbers down, we'd really need to know things like:

    # in the overall grain bill (will help us calculate your mash extraction %)
    preboil volume (9 gallons)
    preboil gravity (1.055)
    postboil volume (before cooling expansion loss)
    postboil gravity (1.061)
    kettle dead space / trub loss (0.75 gallons)
    hop absorption loss (can be ball parked after knowing the postboil volume and amount of kettle hops you added + hop format)
    transfer loss (can be ball parked once we know the postboil volume @ flameout)
    volume in the fermenter (6 gallons)
     
    #5 koopa, Sep 1, 2014
    Last edited: Sep 1, 2014
  6. cpferris

    cpferris Zealot (512) Jan 22, 2008 Indiana
    Trader

    I will try to provide some more insight. I have my grain crushed at mu LHBS. To this point I have not had any issues with the crush.

    The grain bill looked like this:

    16.5# Two Row
    0.75# Crystal 40
    0.75# Carapils
    0.85# Corn Sugar

    Boil hopping looked like this (all pellet):
    3.75 oz CTZ @90
    0.75 oz CTZ @45
    1.00 oz Simcoe @30
    1.00 oz Centennial @0
    2.50 oz Simcoe @0

    I use two 15g stainless kettles for mash and boil. The mash tun has a false bottom, but it has 1.5g of dead-space below the false bottom. What I have been doing is mashing a little more water, and recirculating every 7 min through out the mash. I added 8g of strike at 170 and captured about 4.5g of first runnings. I have an ale pail with graduated markings on the side, so if the level is between 4 and 5, then I estimate 4.5g. I sparged with 4.5g at 177 and then captured a second pail of 4.5g. So that is how I came up with 9g pre-boil.

    I cannot estimate how much was in the pot post boil as I do not have markings on my boil kettle (as well as displacement by the hop bag). So once I cooled the wort, I pulled of 1 gallon at a time with a rubbermaid pitcher to add to my conical. Once I got 6g, I stopped transferring. I estimated that there was about 0.75g left in the kettle (estimate by eyeball there could have been more...its a 15g kettle, so the bottom is quite wide).

    So lets assume that 1.061 is accurate for a sec...I pitched two smack packs of Wyeast 1056 (this was supposed to be a DIPA). So I am hoping I get down to 1.010. That would leave me with 6.7%. Should I stick with the original dry hop schedule (basically 3oz for 12-14 days, then 0.75oz for the last 5 days)? Seems like it wouldn't hurt right?

    Hope this helps. Appreciate the inputs being shared...long time BA to kinda lost their passion with trading and chasing the new stuff, so have found some renewed passion in homebrewing...just trying to get more consistent and not get discouraged. With each of my previous brews, I felt like a took a small step forward with each brew...but this one seems like I reverted.
     
  7. koopa

    koopa Initiate (0) Apr 20, 2008 New Jersey

    18# of grain @ 0.13 gallons per pound = 2.34 gallons of wort lost due to grain absorption

    that reduces your 8g of strike water (which is actually 1.78 qt per lb thickness btw) down to 5.66 gallons of potential 1st runnings to capture

    now if your massive MLT dead space estimate (1.5 gallons) is correct, you only captured 4.16 gallons of 1st runnings
    if your estimate of 4.5g of 1st runnings is correct, then your MLT dead space is closer to 1.16 gallons

    either way, you are definitely losing sugars in that large amount of preboil wort loss range of 1.16 - 1.5 gallons
    but that loss should be the same from batch to batch, so it doesn't really account for why this batch seemed worse

    Lets assume your deadspace is 1.16g and you did collect 4.5 gallons of 1st runnings + 4.5g of second runnings

    Now you have 9g preboil @ 1.055 SG (76% mash extraction for that grainbill)

    If you boil off say 2 gallons over the entire 90 minutes (1.33 gallons per hour), that would reduce you to 7 gallons post boil

    Subtract 4% (0.28 gallons) for cooling expansion loss = 6.72 gallons

    Now if you collected 6 gallons in your fermenter, that leaves 0.72 gallons to lose btw hop absorption, the trub / wort you left behind in the kettle, and any wort left behind in any transfer hoses you might have.

    That puts your brewhouse efficiency at about 61% for this batch with an OG of 1.072

    With your actual OG of 1.061, your brewhouse efficiency was only 51%

    76% mash extraction being reduced to 51% brewhouse is a huge loss of sugar btw the boil kettle and the fermenter. I doubt this is what actually happened and suspect something is wrong with your mash extraction calculation / preboil gravity reading instead.

    You say your preboil gravity reading was 1.039 @ 139F

    How exactly did you measure your preboil gravity? With a hydrometer or a refractometer?

    If with a hydrometer calibrated at 60F, then yes that would equal a 1.055 preboil OG

    If with a refractometer, it might be a refractometer with ATC which means it already adjusted the temperature for you and your actual preboil gravity was indeed 1.039

    If that's the case, you would have 54% mash extraction efficiency and 51% brewhouse efficiency. That 3% gap is more likely than the 25% gap previously mentioned above. It also would make more sense that you had a 54% mash extraction than a 76% mash extraction, considering you are losing at least 1.16 gallons of your wort to your mash tun dead space. I don't see how you could possibly achieve a 76% mash extraction with a batch sparge if you are indeed leaving 1.16 gallons of your 10.16 gallons of potentially collectible runnings behind in your MLT. For comparison, I used to hit 79% mash extraction batch sparging myself and I had 0.19 gallons of dead space in my MLT and had a 13.5 gallon preboil volume. So my dead space was 1.4% of my total potentially collectible preboil volume, while yours is 11.42%

    With regards to your dry hop question, yeah I'd just stick with the same amount of hops. The lower OG might increase your bitterness a bit but, considering PTE already has an insanely high IBU it won't matter.
     
    #7 koopa, Sep 2, 2014
    Last edited: Sep 2, 2014
  8. cpferris

    cpferris Zealot (512) Jan 22, 2008 Indiana
    Trader

    My thought is that by recirculating throughout the mash, I wouldn't lose the entire 1.5g of deadspace. In the future, I am considering removing the false bottom and perhaps replacing it with a bazooka tube instead.

    I had actually calculated the 2.25g boil off amount when I was brewing outside in the winter. I don't get to brew that often, so I had not better number to go off of. I figureed if I was getting 2.25g boil off over 60m, then I might lose closer to 3 with a 90m boil. I think the key thing I have learned is that once the boil has been established, I don't need to hit it with crazy high heat, so the boil off value may be improving.

    I measured pre-boil gravity with my hydrometer and thermometer. I did calibrate the hydrometer, so I didn't figure that was it.

    My gut reaction is...if I want better mash efficiency, I need to get rid of the false bottom if I am going to continue to brewing 6g batches with this 15g setup. Maybe I just need to pickup an igloo cooler for my mash. I got the entire setup I have in a trade for a couple bottles of lambic, so it wasn't a setup I purchased for my usage. I just didn't realize it would make that much difference.
     
  9. VikeMan

    VikeMan Grand Pooh-Bah (3,067) Jul 12, 2009 Pennsylvania
    Pooh-Bah

    Deadspace is the volume of wort (in addition to grain absorption) that won't be drained. It doesn't matter how many times you recirculate... you still lose that volume. Now, your mash efficiency might be higher due to recirculation...in that case there is more sugar in your runnings and more sugar left behind in the deadspace.

    Anything you can do to reduce wort losses will (all other things being equal) increase your mash and/or brewhouse efficiency.

    The more you brew (and take good measurements and notes), the better you'll dial in your system and process. The more you can actually measure (rather than estimate), the better. But estimate what you have to...for example, this beer had a larger grist than your previous batches, but I get the impression you were expecting the same mash efficiency. You can estimate expected changes in efficiency with a little math or a good tool.
     
  10. cpferris

    cpferris Zealot (512) Jan 22, 2008 Indiana
    Trader

    Slightly confused. So obviously I cannot do anything to reclaim the wort absorbed into the grain. But for the deadspace under the false bottom, why do I lose that as well? Wouldn't that liquid also be captured when you open the valve since the valve is below the false bottom? My goal with the recirculation was to try to ensure that the water under the false bottom was run through the grains several times.

    You are right, I assumed I would get the same efficiency as my last 3 brews had been fairly consistent (lower than I wanted, but consistent). Based on this, I adjusted my recipe in beersmith so that I could get the same OG the recipe called for. I feel like I did everything the same, so I was surprised when things didn't work as planned and wasn't sure why.

    Based on your comments, is there a more accurate way I should be measuring?

    Again...I do appreciate all the responses...very helpful.
     
  11. VikeMan

    VikeMan Grand Pooh-Bah (3,067) Jul 12, 2009 Pennsylvania
    Pooh-Bah

    If the liquid is draining from it, then it's not a deadspace. I talked about deadspaces, because you had identified it as one.

    Bigger grists will have lower mash efficiency than smaller grists. You can use something like the Mash Efficiency Predictor in Brewcipher to estimate how the efficiency will change. Or you can do it be feel/experience, but it doesn't sound like you're quite there yet.

    I would measure all your equipment/process (true) deadspaces/losses. Also, measure (rather than eyeball) all your volumes.
     
  12. hopfenunmaltz

    hopfenunmaltz Pooh-Bah (2,647) Jun 8, 2005 Michigan
    Pooh-Bah

    You have a hose on the ball valve outlet, right? The dip tube will get most of the wort out if you have a hose that goes below the bottom of the kettle. If not you can only drain to the ball valve height, and then it breaks the siphon.

    I have a similar set up. BTW. Might leave a pint behind.
     
  13. sjverla

    sjverla Initiate (0) Dec 1, 2008 Massachusetts

    Are you sure your thermometer is calibrated? I lost 15% efficiency when mine was out of whack.
     
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