grain/hop bill different for biab/a.g.

4th biab brewed and have been using biabrewer calculater. the thing is all the recipes so far have been for A.G. and when using there calcs the bill is much higher for biab. for example . Summer Lightning brewed last night, for 23ltrs A.G. recipe grain bill was 4990g, biab recipe was 5855g.All brews so far, i've used the biabrewer higher grain/hop bills and the o.g.'s haven't been that far off except by errors on my side. Last night ended with o.g. of 1.058 instead of 1.049, but think that was due to using both elements and probably too vigorous a boil and losing a couple of litres. Not overly concerened, just wondered is that the case with biab. cheers, dave.

afaik you can expect a lower b/h efficiency with biab, even with a dunk sparge your not usually going to rinse off as many sugars as with a 2-3v and batch or fly sparge.

Fil said:

afaik you can expect a lower b/h efficiency with biab, even with a dunk sparge your not usually going to rinse off as many sugars as with a 2-3v and batch or fly sparge.

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. So the higher grain bill compensates for the lower efficiency. i.e. more grain needed doing biab to extact the same amount of sugar as an A.G. recipe.Thanks, dave.

Fil said:

afaik you can expect a lower b/h efficiency with biab, even with a dunk sparge your not usually going to rinse off as many sugars as with a 2-3v and batch or fly sparge.

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That might be true but I've been using recipes from the Greg Hughes book and although I'm doing BIAB instead of normal AG I'm getting the predicted OGs. I mash for longer than the book says (1 1/2 hours instead of 1 hour) and dunk sparge after draining and squeezing.
It's funny, but the book hardly gives BIAB a mention when I would have thought it would be most peoples easy entry into all grain...

I think it is likely to be efficiency. I used BIAB for a year at 70%ish efficiency. Then went to mash tun and sparge at 85%. Sparge puts an additional hour on the brew day though.

Cwrw666 said:

That might be true but I've been using recipes from the Greg Hughes book and although I'm doing BIAB instead of normal AG I'm getting the predicted OGs. I mash for longer than the book says (1 1/2 hours instead of 1 hour) and dunk sparge after draining and squeezing.
It's funny, but the book hardly gives BIAB a mention when I would have thought it would be most peoples easy entry into all grain...

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how are you doing your sparging? at the moment i've been just pulling the bag out after raising the temp for 10mins, sqeezing the hell out of it over a grill on top of a f.v. then pouring back into boiler.p.s. do you stir the grains during mashing? i did stir 3 or 4 times on the 1st couple i did but the temp kept dropping. last nights one , i just stirred after 90mins whilst bringing the temp up to 76c for an extra 10 mins. cheers. dave

Fil said:

afaik you can expect a lower b/h efficiency with biab, even with a dunk sparge your not usually going to rinse off as many sugars as with a 2-3v and batch or fly sparge.

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Interesting. I follow a lot of the receipe's from GW's book. I'm pretty sure his recipes are/were initially aimed at the 3V brewer as nowhere in the book does it mention BIAB. I always hit my OG target (unless I do a beer above about 5% because I do a concentrated wort/maxi biab but this is a different issue)and don't add any extra grain. I put this down to stirring my grains half way through during the mash and a super long lauter, I also do two dunk sparges btw. My last brew came out at 83% efficiency (if I calculated things correctly)

davereal said:

how are you doing your sparging? at the moment i've been just pulling the bag out after raising the temp for 10mins, sqeezing the hell out of it over a grill on top of a f.v. then pouring back into boiler.p.s. do you stir the grains during mashing? i did stir 3 or 4 times on the 1st couple i did but the temp kept dropping. last nights one , i just stirred after 90mins whilst bringing the temp up to 76c for an extra 10 mins. cheers. dave

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So, I have 5 gallons in the boiler which I set at 65 degrees. Then I put the grain bag in and start pouring in the grain, stirring it in to avoid clumping. I leave the boiler running with the thermostat set at 65 so I'd guess the temperature fluctuates quite a bit. Stirring the grain occasionally. Mash like this for an hour and a half.
Then I tie the grain bag to a rope which I have running through an eye bolt in the roof above and yank the bag up leaving it to drain into the boiler. When it stops dripping I squeeze it like crazy and get about a gallon of liquid out.
Then I put 2 kettle worths of boiling water into an FV along with a bit of cold, dunk the grain bag in and work it a bit so it's well wetted. Hoist it out again with the rope and let it drain into the boiler, followed by another good squeeze. Also tip the fluid from the FV back into the boiler. This usually refils the boiler to the 5 gallon mark.
Then I do the boil, setting the thermostat for 100. This lets it boil on and off for about an hour and a half, rather than a rolling boil all the time. Even so I haven't done a boil yet without getting a boilover! Don't seem to loose too much by evaporation though - it usually only takes a couple of kettlefulls of boiling water to get back to 5 gallons.

cheers guys.i'll have a go at sparging next brew. just wondering thou, would you put slightly less water in when mashing because you'd be adding a few litres of sparge water. if that makes sense. been using biabrewer calcs for volumes which give gives you water required for grain bill and to obtain 23 litres in f.v..thou these are based on estimates of evaporation/ trub loss etc.keep meaning to put in my own calcs . thanks

just to clarify when i said a biab brew can expect a lower b/h efficiency, i wouldnt have thought it would need the best part of an extra kg of grain to compensate, more like the difference between a batch and fly sparge where an extra handful or 2 of grain can compensate for the option to go with a batch sparge..

Fil said:

just to clarify when i said a biab brew can expect a lower b/h efficiency, i wouldnt have thought it would need the best part of an extra kg of grain to compensate, more like the difference between a batch and fly sparge where an extra handful or 2 of grain can compensate for the option to go with a batch sparge..

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I took your advice on the extra couple of handfuls for batch sparging - absolutely positive it's made a difference - thanks for that!

Fil said:

just to clarify when i said a biab brew can expect a lower b/h efficiency, i wouldnt have thought it would need the best part of an extra kg of grain to compensate, more like the difference between a batch and fly sparge where an extra handful or 2 of grain can compensate for the option to go with a batch sparge..

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yep. that's why i asked. cos using biabrewer calcs , even next to g.w. recipes like for like , required near on an extra 1kg of grain and the extra 10% to 15% of hops. so shall do a g.w. recipe and sparge and see how that turns out.cheers.

p.s. i think i half get the difference between calcs. biabrewer and one pot brewers don't think you needed to sparge. as in over complicating the whole element of one pot brewing and to compensate for simplicity and time saved requires a higher grain bill.sorry , does that sound about right . what ever suits you. for me, biab's more about space constrictions. i have the time, so defo give the sparging a go. cheers. dave