Mini BIAB - mash / sparge water volumes

Discussion in 'General Brewing Discussions' started by Brewer #196727, Oct 10, 2018.

  1. Anth M

    Anth M Member

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    Howdy,

    I'm an all grain mini-BIAB noob (done 2 brews) and have some questions about water quantities.

    Generally I mash in a 32L pot on the stove and do a dunk sparge (sometimes I rinse over the wort, what's better?) and I want to know if it matters how I split the mash and sparge water up? For example could I always use 8L for the mash and 12L for sparge regardless of beer type? I understand if I use more water it's more "diluted" but would it balance out if you used less sparge water?

    I've also noticed when trying to scale recipes the mash volume is often less, like 5-6L. So my question is, does it matter if you have more water than recommended in a mash/sparge or can that effect things? Wouldn't you still end up with the same SG if you did your calcs right?

    Thanks for any input.
     
  2. Mark Farrall

    Mark Farrall Well-Known Member

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    I use a similar size and don't bother with the sparge. I just add all the water the recipe builder tells me I'll need at the start and allow 90 minutes for the mash.

    I check the gravity with a refractometer at 60, 75 and 90 minutes. If I've hit boil gravity at 60 or 75 minutes I'll pull the bag and let it drip while it comes to the boil. If I get to 90 (which is hardly ever) I'll pull the bag and start the boil while it drips regardless of the gravity.

    I've recently added a sous vide stick to the setup for mashing, so it makes keeping temperatures very easy. Ends up being a very relaxing part of the brew day as I'm generally reading a book or something similar while I wait for the alarm to go off.
     
  3. MDIAZ

    MDIAZ New Member

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    It depends on the amount of grain you use.
    I use 3 or 3.5 Liters of water for 1 kg of malt.
    Example: Batch size on fermentor. 50 Liters.
    Boil Size: 60 Liters. ( I have 10 liters of losses during 60m of boil.)

    So:
    For 10 kg of malt, I use 30 liters for mash. 3Lt X 10Kg= 30Lt
    The grain absorb aprox 1 liter for 1 kg of malt. so you really have at the end of mash 20 liters. 30Lts- 10Lts= 20Liters

    Amount of water for Sparge =
    Boil size 60Liters - 20liters.= 40Liters for sparge

    Its the same if you use 3.5 Liters for 1Kg Malt.

    Example: Batch size on fermentor. 50 Liters.
    Boil Size: 60 Liters. ( I have 10 liters of losses during 60m of boil.)

    So:
    For 10 kg of malt, I use 35 liters for mash. 3.5Lt X 10Kg= 35Lt
    The grain absorb aprox 1 liter for 1 kg of malt. so you really have at the end of mash 25 liters. 35Lts- 10Lts= 25Liters

    Amount of water for Sparge =
    Boil size 60Liters - 25liters.= 35Liters for sparge

    i recommend use one of these two options

    Sorry for my english
     
  4. zised

    zised New Member

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    Your kettle is large enough that you can do a full volume Mash.

    It should look something like this depending on your setup.

    Total mash water needed 18.2
    Grain absorption losses -2.5
    Starting boil volume 15.7
    Boil off losses -5
    Kettle dead space -0.5
    Hops absorption losses -0.2
    Amount going into fermentor 10
    Total: 18.2
     
  5. Anth M

    Anth M Member

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    Thanks Mark.

    That's an interesting technique - I hadn't thought of ditching the sparge altogether and it would save time. What about all the talk of rinsing the grains etc, I guess if you're hitting your numbers who cares. I wouldn't be able to take samples during the mash as I'd have to lift the lid which kills my temp - I use a conventional gauge that screws into the pot.
     
  6. Anth M

    Anth M Member

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    Thanks for your help everyone.

    MDIAZ - your English is very good btw.

    Mark & zised - think I'll give the full-mash a go, tks for the tip!
     
  7. Mark Farrall

    Mark Farrall Well-Known Member

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    Yep, you lose a bit of efficiency with what I'm doing, but I'm happy to spend the extra dollar or so on grain for less stuffing around. If you are trying to get a few extra points at the end you can always do what one of the other posters here suggests and squeeze the bag like it owes you money. Definitely makes a difference when I've done it.

    Some will say squeezing can add tanins to the beer, but I haven't seen anything compelling about how that happens and haven't experienced it. Tanins can definitely be extracted during mashing, but it seems to be more related to pH and temperature more than anything mechanical. So probably easier to do with an overly hot sparge than squeezing your bag.

    And I wouldn't worry about a few degree drop (either C or F) during your mash. With the well malted grains we generally use, most of the conversion is probably done long before you even think to take a sample.
     
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  8. Hawkbox

    Hawkbox Well-Known Member

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    Bah squeeze it like it owes you money. I mash in a bag as well and it works great.
     
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