So I did my first bigger brew today. Had previously only done one gallon brews, got my bigger equipment and was ready to go bigger. Did a 3 gallon BIAB from Northern Brewer. I followed the instructions, which said to use 5.5 gallons of water for the mash. I ended up with over a gallon extra. My preboil volume was about 5.25 gallon, which seemed too high. The kit contained 7 lbs of grains. Obviously I should have used a gallon less, but I'm trying to figure out why I ended up with so much extra? I used a Wilserbrewer bag, and squeezed a lot of wort from it, but certainly not a gallon. Missed my OG by 10 points, but got a gallon of extra brew.
How much water would you use?
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McKnuckle
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The kit can't tell how much wort will evaporate during your boil, and they don't want to "short change" customers on the final volume, so they over-compensate at the start with enough water for everyone.
Expect to lose 0.065-0.11 gal/lb of grain due to absorption. Vigorous squeezing or a lengthy gravity drain gets you the smaller figure; no squeezing or minimal drain the larger. End result will be your pre-boil volume at whatever gravity you measure.
When you boil, evaporation concentrates the wort to a greater or lesser degree, producing OG. The difference in OG can be dramatic if you boil off much less (or more) than anticipated. Do a boil test in your kettle with carefully measured plain water, and use that figure to help estimate your starting volume more accurately the next time.
Expect to lose 0.065-0.11 gal/lb of grain due to absorption. Vigorous squeezing or a lengthy gravity drain gets you the smaller figure; no squeezing or minimal drain the larger. End result will be your pre-boil volume at whatever gravity you measure.
When you boil, evaporation concentrates the wort to a greater or lesser degree, producing OG. The difference in OG can be dramatic if you boil off much less (or more) than anticipated. Do a boil test in your kettle with carefully measured plain water, and use that figure to help estimate your starting volume more accurately the next time.
LostHopper
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+1 McKnuckle
Boil off rates vary with the kettle and the vigor of the boil.
Using a long spoon with gallon marks can give you an idea where you are during the boil. Probably not recommended but I would have just boiled a little longer.
Sometimes I wonder if the atmospheric conditions can affect boil off rate (I brew outside). Seems like a cold dry day will boil off more.
5.5 gallons doesn't sound off to me. I just brewed a 4 gallon batch. I wanted just less than 4.5 to go into the fermenter. I started with 7 gallons and 10 lbs of grain. Came out perfect.
Boil off rates vary with the kettle and the vigor of the boil.
Using a long spoon with gallon marks can give you an idea where you are during the boil. Probably not recommended but I would have just boiled a little longer.
Sometimes I wonder if the atmospheric conditions can affect boil off rate (I brew outside). Seems like a cold dry day will boil off more.
5.5 gallons doesn't sound off to me. I just brewed a 4 gallon batch. I wanted just less than 4.5 to go into the fermenter. I started with 7 gallons and 10 lbs of grain. Came out perfect.
pricelessbrewing
Brewer's Friend Software Manager
See the link in my sig for water volumes, temps, and efficiency analysis. Easy to use, very useful, and very accurate. Let me know if you have any questions.
Smaller batches can be more difficult volume wise as boil off is a large percentage of batch size.
As said above, it is helpful to make a simple dip stick volume measuring device, or just a couple marks on your brew spoon indicating pre and post boil volume, so you can check your progress compared to anticipated results. Realize that the hot wort volume will shrink a bit on cooling, about 4% I think.
If over volume, you can extend the boil, just time your late addition hops to flame out.
As said above, it is helpful to make a simple dip stick volume measuring device, or just a couple marks on your brew spoon indicating pre and post boil volume, so you can check your progress compared to anticipated results. Realize that the hot wort volume will shrink a bit on cooling, about 4% I think.
If over volume, you can extend the boil, just time your late addition hops to flame out.
madscientist451
Well-Known Member
With my kettle/stove the water calculations seem about right:
3 gallon batch
0.7 gallon absorption
1 gallon evaporation (your evaporation may be more or less)
.5 gallon kettle/fermenter trub
--------------------------------
5.2 gallons
You could have made the extra .010 in wort gravity by doing a batch sparge or a dunk sparge in a side pot.
Next time, if you have an extra pot, put 3.2 gallons in main pot and do BIAB as normal, in a side spaghetti pot put 2 gallons and heat to 168. When mash is done pull bag from main pot and place it in side pot.
Crank up the heat in the main pot and stir the grains in the side pot. After 10 minutes, combine the two and let the bag drain some more into the side pot.
Check your gravity about 5-10 mins, before boil is done by pulling a sample and placing in ice bath. If your gravity is low, you can add some DME or extend the boil to evaporate more water. Delay your late hop additions until you have done this. After a few batches you will figure a way that works best for you, as there are many different routes to the same goal and no "right" or wrong way to BIAB. The goal is to hit your numbers without adding DME or extending the boil but it takes some trial and error to make it all work out with the equipment you have. Once you know your evaporation rate you can also take a pre boil gravity reading and calculate where you will be at the end of the boil. Another way is to just use a little more grain if you are always coming up short on your gravity numbers.
Also, to ferment a 3 gallon batch, I use a 5 gallon carboy, and end up with 3.5 to 3.75 gallons in the fermenter. That gives me plenty of headspace for the yeast and I'll still get 3 gallons of beer after trub/yeast cake loss. Cheers!
3 gallon batch
0.7 gallon absorption
1 gallon evaporation (your evaporation may be more or less)
.5 gallon kettle/fermenter trub
--------------------------------
5.2 gallons
You could have made the extra .010 in wort gravity by doing a batch sparge or a dunk sparge in a side pot.
Next time, if you have an extra pot, put 3.2 gallons in main pot and do BIAB as normal, in a side spaghetti pot put 2 gallons and heat to 168. When mash is done pull bag from main pot and place it in side pot.
Crank up the heat in the main pot and stir the grains in the side pot. After 10 minutes, combine the two and let the bag drain some more into the side pot.
Check your gravity about 5-10 mins, before boil is done by pulling a sample and placing in ice bath. If your gravity is low, you can add some DME or extend the boil to evaporate more water. Delay your late hop additions until you have done this. After a few batches you will figure a way that works best for you, as there are many different routes to the same goal and no "right" or wrong way to BIAB. The goal is to hit your numbers without adding DME or extending the boil but it takes some trial and error to make it all work out with the equipment you have. Once you know your evaporation rate you can also take a pre boil gravity reading and calculate where you will be at the end of the boil. Another way is to just use a little more grain if you are always coming up short on your gravity numbers.
Also, to ferment a 3 gallon batch, I use a 5 gallon carboy, and end up with 3.5 to 3.75 gallons in the fermenter. That gives me plenty of headspace for the yeast and I'll still get 3 gallons of beer after trub/yeast cake loss. Cheers!
Try this, it has worked well for me
http://www.brew365.com/mash_sparge_water_calculator.php
http://www.brew365.com/mash_sparge_water_calculator.php
Here is what I use.
final batch size + absorption + trub loss + boil off = water needed
absorption is grain weight x .075 (or x .05 depending on how hard you squeeze the bag)
Not sure if you did this or not but you should boil say 4 gal of water for a hour and see what your boil off is.
If its a kit or if its from software I always use this calc to find out how much water I need
final batch size + absorption + trub loss + boil off = water needed
absorption is grain weight x .075 (or x .05 depending on how hard you squeeze the bag)
Not sure if you did this or not but you should boil say 4 gal of water for a hour and see what your boil off is.
If its a kit or if its from software I always use this calc to find out how much water I need
OP
OP
PADave
Well-Known Member
Thanks for the tips. My kettle has markings, so I can easily see how much boils off and where I'm at. I did squeeze the bag pretty good, so I didn't loose much to absorption. I was just a little surprised by how much I missed the volume by. But I still made beer, I learned something, and I'll do better next batch.
Yea, it's easy to do lol, now you know to watch the kettle markings so no excuses moving forward!
Just kidding have fun
Often I don't really even time the boil, but rather boil to a specific volume and just time my late hops to the end...
55-60-70 minute boil, it's all good
Just a tip that works for me, I prefer a little extra wort and risk the possibility of needing to boil for a few minutes.
It doesn't have to be rigid
Yea, it's easy to do lol, now you know to watch the kettle markings so no excuses moving forward!
Just kidding have fun
Often I don't really even time the boil, but rather boil to a specific volume and just time my late hops to the end...
55-60-70 minute boil, it's all good
Just a tip that works for me, I prefer a little extra wort and risk the possibility of needing to boil for a few minutes extra than being short
It doesn't have to be rigid
dstockwell
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I do 3G BIAB and on my first batch (was not a kit) I followed the NB philosophy of 5.5G, I ended up the same way you did. Then started using Priceless BiabCalc and pretty much start with 5G now based on my boil off, etc.
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