BIAB Brew Day

[Nosybear]

Brewed on Sunday evening. Decided after hearing a few people say a mash out isn't really necessary to not do a mash-out. Also kept the lid 3/4 on to try and prevent to much water loss. Ended with 23 litres where my usual is 21-22 litres. However, my OG was 1.042 and expected was 1.050. Is that because I didn't do a mash-out? Fermentation seems to be going along nicely....

A little math: v1g1=v2g2. This means the amount of sugar in a wort is constant, so the product of volume times gravity is always equal for a given wort. You had 23 liters at 1.042 - 42 gravity points. Multiplying 23*42 gives 966 points total. Divide that by your usual 21 liters and you get 46 points, or 1.046. You still missed by .004 but that's not much: 22 points or less than a half Kg of sugar. So I'd guess two things are working here: You undershot gravity a bit and wound up with too much wort. As to why? 0.004 points of SG is within expected error. Keeping the lid on the boil affected the boil-off rate..

Mash-out would have nothing to do with it. Possibilities are crush, mash temperature variation, the grain itself.

 

[Pricelessbrewing]

A little math: v1g1=v2g2. This means the amount of sugar in a wort is constant, so the product of volume times gravity is always equal for a given wort. You had 23 liters at 1.042 - 42 gravity points. Multiplying 23*42 gives 966 points total. Divide that by your usual 21 liters and you get 46 points, or 1.046. You still missed by .004 but that's not much: 22 points or less than a half Kg of sugar. So I'd guess two things are working here: You undershot gravity a bit and wound up with too much wort. As to why? 0.004 points of SG is within expected error. Keeping the lid on the boil affected the boil-off rate..

Mash-out would have nothing to do with it. Possibilities are crush, mash temperature variation, the grain itself.

Could also increase efficiency by sparging.

Mash pH has a role in conversion as well, but it's pretty weak unless it's significantly off.

 

[RalphK]

A little math: v1g1=v2g2. This means the amount of sugar in a wort is constant, so the product of volume times gravity is always equal for a given wort. You had 23 liters at 1.042 - 42 gravity points. Multiplying 23*42 gives 966 points total. Divide that by your usual 21 liters and you get 46 points, or 1.046. You still missed by .004 but that's not much: 22 points or less than a half Kg of sugar. So I'd guess two things are working here: You undershot gravity a bit and wound up with too much wort. As to why? 0.004 points of SG is within expected error. Keeping the lid on the boil affected the boil-off rate..

Mash-out would have nothing to do with it. Possibilities are crush, mash temperature variation, the grain itself.

Thanks! I was wondering how to calculate this! Awesome!

 

[RalphK]

Just a follow up. Final Gravity was spot on at 1.005. I have bottled it and it looks pretty good- some nice aroma as well.