Question about screwed up 1 gal batch

Discussion in 'Homebrewing' started by AlexFields, May 24, 2013.

Thread Status:
Not open for further replies.
  1. AlexFields

    AlexFields Pooh-Bah (1,912) Dec 13, 2009 Tennessee
    Pooh-Bah Trader

    Had a brew day yesterday, and for the first time I tried brewing an experimental 1 gal batch in the kitchen at the same time as I brewed a 5 gal batch outside. The big batch went smoothly, the 1 gal batch definitely did not.

    I'll post the recipe I used at the end of this post, but basically I screwed up the wort volume estimates and way underestimated volume loss to the boil and trub. Recipe was calculated to give me 1.056 OG and 51 IBUs. I ended up with a little less than half a gallon going into fermenter with way too high gravity. I even added some of the trub into the fermenter to make sure I was getting all the viable wort. I boiled another half gallon or so of water to dilute and bring up to around the volume I wanted, and ended up with an OG of 1.040.

    This was a small experimental batch so I'm not devastated at the idea that I'll just have a lighter beer, I think the recipe would do just fine scaled down to 1.040 OG. BUT I'm wondering if I should expect the hop character to be scaled down proportionally to the gravity or if it will be too low. Can I assume that when I boiled off too much volume, I effectively concentrated both the sugars and the hops, and then diluted both proportionally when I added more water? Any feedback, either on a theoretical level or from personal experience with results from similar screw ups, would be appreciated.

    And one more question: to reduce wort loss on 1 gal batches in the future, should I just started with a lot more water, or can I get away with a shorter boil (30 mins?) too?

    Here's the recipe (this is the 5 gal batch recipe, I just scaled down by dividing by 5.

    Meridian Single Hop Pale Wheat

    GRAIN
    5.5 lbs Great Western Premium 2-row
    4.5 lbs White Wheat Malt

    HOPS (all Meridian, 6.7% AA)
    0.5 oz 60 min
    0.75 oz FWH (20 min)
    1 oz 15 mins
    1.25 oz 10 mins
    1.5 oz 5 mins
    2 oz hop stand
    4 oz dry hop

    Safale US-05 yeast

    Estimated OG 1.056
    Theoretical IBUs 51

    If the OG and IBUs went down proportionally, that would give me a beer with an OG of 1.040 and IBUs around 36, which sounds like a nice, light hoppy wheat--probably closer to a standard pale wheat than the recipe I originally calculated, which was more like a wheat IPA. I'm just wondering if that's what I really have now.

    Thanks!
     
  2. VikeMan

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

    Start with more water. And if you (or your software) estimate boil losses as a percent of volume lost per time period, that's going to cause you problems as you go to different batch sizes. For a given kettle and vigor of boil, etc., evaporation rates should be estimated in volume per time period (e.g. gallons per hour) and not percentages of volume per time period (e.g. 15% per hour).
     
    inchrisin likes this.
  3. VikeMan

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

    To an extent, yes. But when your average boil volume was less than you expected, your hop utilization efficiency would have suffered. ('X' amount of hops will have better utillization in a large wort volume than it will in a smaller wort volume.)
     
  4. AlexFields

    AlexFields Pooh-Bah (1,912) Dec 13, 2009 Tennessee
    Pooh-Bah Trader

    I wasn't using software, I was just sortof guessing. I was planning for a higher % loss than I get in 5 gal batches, but obviously wasn't expecting quite the loss I got. I also wasn't expecting the large amount of trub in the kettle from such a small amount of hops.

    Do you have recommendations for how approximately much pre-boil wort is necessary to end up with a gallon (or really more like 1.25 gallons to allow for trub loss)? I tried finding guidelines for 1 gal batch mashing before I did this but couldn't really find anything.
     
  5. VikeMan

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

    Have you used the same kettle/heat for 5 gallon batches? If so, the volume that boils off will be the same for a one gallon batch.

    If you have nothing to compare to... you can determine it experimentally...put a known volume of water in the kettle and boil it for some amount of time. Let it cool and measure.

    Or, even easier...you know how much wort you ended up with and you had to add a half gallon to get back up to your intended volume. So start with a half gallon more.
     
  6. VikeMan

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

    Sorry, I missed the trub loss part originally. Trub loss is a function of the type (pellet or leaf) of hops and the amount of hops. You sort of learn these rates by experience. When I get home, I'll look up and post the numbers I use in my sheets, which you could use as a starting point until your system/process is dialed in. Or maybe someone else can post theirs sooner.
     
  7. AlexFields

    AlexFields Pooh-Bah (1,912) Dec 13, 2009 Tennessee
    Pooh-Bah Trader

    Yeah I have trub loss amount pretty well figured out on my 5 gal system, I was assuming that it would be proportionally the same for a 1 gal batch but it seemed to be considerably higher. Maybe my perception was skewed since I was seeing the trub in relation to a greatly diluted post-boil wort size and not in relation to the batch size as it should have been, but it seemed like a crazy amount.
     
  8. VikeMan

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

    Your trub loss should scale perfectly. Think of it like a sponge. One sponge can hold 1/5 the total volume of water that 5 sponges can hold.
     
Thread Status:
Not open for further replies.