Missed Original Gravity

Discussion in 'Beginners Brewing Forum' started by Brewer #345301, Jan 22, 2021.

  1. WheatBeerCH

    WheatBeerCH New Member

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    Hello,


    I brewed an American IPA a week ago and would like anyone's opinion on how to better manage gravity when I brew next week.


    I used this recipe: https://www.beercraftr.com/1-gallon-american-ipa-recipe/


    The OG at the end of the mash was catastrophic: 1.020 (target was 1.070). Since I measured when the temp was around 150F, the OG was no doubt higher (1.030??), but I didn't do the calculation at the time. I was expecting low efficiency with BIAB, so I had DME on hand. I calculated that I needed 600 grams (eek!) but added just 500 because it already seemed like too much. Needless to say, I overshot the target OG. I measured after the boil and it was at 1.080 (at 70F).

    I have grains for the next three batches that were already milled (the LHBS wouldn't grind for BIAB or run it through twice). So, next time, I will make these adjustments:
    • add more grain than in the recipe. but how much more would you suggest?
    • do a proper mash out (I skipped the step in the first batch)
    • the recipe called for 9.25l of strike water for the mash. perhaps I should mash in, say, 7l of water and sparge the BIAB at 170F at the end of the mash with 2.25l?
    Should I check the OG before the boil? If necessary, should I add DME before or after the boil?

    The final gravity target is 1.015. Since there is not actually that much beer, I am hesitating to test OG several times, but suppose I have to in order to find the correct moment to bottle it up. Or, would it be safe to leave it in the fermenter 3 weeks, without testing OG, and try to bottle?

    If my starting OG was 10 points above the target, will my FG also be 10 points above the target?

    Here's next week's brewday recipe: https://www.beercraftr.com/1-gallon-american-pale-ale-ii/


    Thanks for any tips!
     
  2. philjohnwilliams

    philjohnwilliams Well-Known Member

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    For that big a difference in gravity I have to ask if the grains were crushed or not.
     
  3. SabreSteve

    SabreSteve Well-Known Member

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    I honestly don't know what to do with an OG that low because it's only a few points above where many beers finish. There might not be a ton to ferment in there TBH. Maybe someone else can give you more wisdom there. Honestly if your LHBS won't grind for BIAB I'd find a new one. You could also buy a corona mill in the neighborhood of $30 USD and mill your own grains. It's also easily converted with a hex bolt to be cranked with your power drill. Add a bucket (I use a bucket with the bottom cut out and place it inside another bucket ) a 2x4 to mount it on and a some kind of spray shield and you can mill (and mill again) all your grains in just a few minutes.

    Other than that always take your gravity post mash. There's a hydrometer correction tool on here that goes up to 159F. then calculate how much DME you need to add and add it then prior to the boil
     
  4. WheatBeerCH

    WheatBeerCH New Member

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    The grains were definitely crushed.

    I did the full 75 minute mash, kept the temperature steady. I had already calibrated my thermometer.
     
  5. SabreSteve

    SabreSteve Well-Known Member

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    Sorry. Read wrong... Missed that it was up to 1.080!! You're FG won't necessarily be higher. Might end up similar to what you expected which means a higher alcohol content. Of course as long as you don't go over the alcohol tolerance of your yeast.
     
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  6. WheatBeerCH

    WheatBeerCH New Member

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    Thankyou, SabreSteve!

    I already have milled grains, so i'm gonna give it another try with what I have. I should be able to improve on the initial fiasco.

    If I measure and miss the target initial OG by 10 points or so, is it such a big deal? I mean, the beer will just taste different, right? Should I have to add the DME to get it spot on?
     
  7. SabreSteve

    SabreSteve Well-Known Member

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    Someone could correct me if my math is off (@Nosybear ) but that's like a 1% change in ABV I believe. So I might leave that up to you if that makes a difference. Also just thought of, are you squeezing your grain bag when you take it out? That's a little thing that possibly help out your efficiency.
     
  8. WheatBeerCH

    WheatBeerCH New Member

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    I did not squeeze the bag, but realize that it could help out even more. I will definitely do it next time.

    What do you think about these options ... ?
    • add more grain than in the recipe. but how much more would you suggest?
    • do a proper mash out (I skipped the step in the first batch)
    • the recipe called for 9.25l of strike water for the mash. perhaps I should mash in, say, 7l of water and sparge the BIAB at 170F at the end of the mash with the leftover 2.25l "clear" water?
     
  9. SabreSteve

    SabreSteve Well-Known Member

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    -You can add more grain but it's going to depend on your batch size and efficiency. I'd put the recipe in the recipe editor here. You don't know exactly what you're efficiency is so I'd set it to 50% maybe which is low but eers on the side of caution. Put the recipe in as you have it and then click on the green goals button under fermentables. Enter your desired OG and it'll scale your grain bill to fit that number. Then when you brew create a brew session with that recipe and create logs in there with your OG readings so you can figure out your efficiency.
    -mash out shouldn't matter if you're going straight to the boil after the mash anyways. All it does is stop enzymatic activity.
    -I don't sparge in BIAB. I just do a full volume mash and then boil down to my desired volume. Squeezing the bag accomplishes a lot of what sparging does. What I will do though is I'll heat up an extra gallon of water and then pour it over my drained grain bag. Then if I'm short on my volume I'll use that kinda thinner wort to top it up a bit.
     
  10. BarbarianBrewer

    BarbarianBrewer Well-Known Member

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    Using the hydrometer calculator (under tools) indicates that a gravity of 1.020 at 150 F is really 1.038. Not 1.070 but, closer. I'm not sure how accurate the converter is when the sample temperature is that high. So, you may be closer to target than 1.038. If your post-mash/pre-boil gravity is off by more than 10 points I'd add DME (if low) or water (if high) to get it closer. If it's less than 10 points I'd probably leave it and try and improve my process next time.

    As far as how much to increase your grain by, you first need to learn your extraction efficiency. And the only way to do that is to brew multiple times and measure.

    I always skip the mash-out. The goal of a mash out is to stop the conversion process. Professional breweries need to do they know exactly what they are working with. On the homebrew scale, a little more sugar in the wort can only be a good thing.

    Mashing with 7L and sparging with 2.25L sounds fine. I think it will boost your efficiency a bit.
     
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  11. WheatBeerCH

    WheatBeerCH New Member

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    @SabreSteve
    I plugged the recipe in the website editor. I cannot find the combination that ends up with the OG in the original BeerCraftr recipe, which was 1.070. I only end up with something around 1.044 - 1.053. Is it possible the original recipe is just incorrect? Maybe I added that 500g DME for nothing!!

    @BarbarianBrewer
    Thanks for the tips! I will closely measure and use the tools on the website.
     
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  12. SabreSteve

    SabreSteve Well-Known Member

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    Try this button. Of course it'll be based on whatever you have the efficiency set to for the recipe and you won't know your actual efficiency until your figure out your equipment and process. For now it's all a bit of guess work Screenshot_20210122-184242.jpg
     
  13. WheatBeerCH

    WheatBeerCH New Member

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    OK, I understand what you're saying. So for example, here it looks like i would need roughly one addition pound grain to get the goal of 1.070 with 50% efficiency ... Is that a reasonable conclusion with this calculator? Thanks again, its a very helpful conversation!

    Normally the recipe called for 2.75 lbs US Pale Malt and 4 oz Caramel Malt.

    upload_2021-1-23_0-54-29.png
     
  14. SabreSteve

    SabreSteve Well-Known Member

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    That sounds like it's probably right. See if that gets you closer and you can always still adjust up with DME or down with water
     
  15. Megary

    Megary Well-Known Member

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    #15 Megary, Jan 23, 2021
    Last edited: Jan 23, 2021
    That recipe you linked doesn’t state what efficiency it is based on. That seems a bit suspect to me. In other words, if the recipe is based on 80% efficiency and you typically get 65...well you never had a chance to begin with.

    When you crush your grains for BIAB, you want to see a fair amount of flour and the grains should be crushed much finer than standard mash/sparge brewing. “Crush ‘til you’re scared” is a common saying for BIAB. In short order, you’ll have it dialed it in.

    Also when measuring your (pre-boil, post-boil) gravities, keep in mind that they are a function of your volumes. If you have too much or too little volume, that will reflect in your gravity readings.

    Good luck!
     
  16. Mark Farrall

    Mark Farrall Well-Known Member

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    To reduce the amount of wort/beer you lose to testing, you could use a refractometer instead of a hydrometer (assuming you're using a hydrometer). Only uses a few millilitres each sample.
     
  17. BarbarianBrewer

    BarbarianBrewer Well-Known Member

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    That is exactly what I do. Three weeks in primary, one hydrometer measurement, then bottle.
     
  18. SabreSteve

    SabreSteve Well-Known Member

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    I do 5 gallon batches and I still only do one reading. I actually do have a refractometer but you still need a hydrometer for several brews in order to determine your wort correction factor that you'll need for the refractometer calculator. I've actually been lazy and haven't even bothered with the refractometer for my last 2 brews
     
  19. Mark Farrall

    Mark Farrall Well-Known Member

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    Depends on you desire for precision. I do a few batches with both, see how close they are and then stop using the hydrometer for months. But then I'm not that fussed with the accuracy of the finished beer.
     
  20. WheatBeerCH

    WheatBeerCH New Member

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    Since my grain for the next three batches are already milled, maybe I should drop the BIAB method for them and use a traditional sparge without the bag?

    Or, if I stick with BIAB isn't it quite similar to sparge hot water over the bag after pulling it out at the end of the mash? How would it be different without the bag?
     

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