First boil in a bag brew - damn, how did that happen!?

[Seghes]

I’m still very new to home brew, done about 6 ag brews, quite successfully. Tried a Jon Finch recipe for Hefe Weiss (wheat beer). All went to plan until I transferred to FV and got a SG reading of 1040 - way off the anticipated 1050. Three days later I’m only getting 2 repeat readings of 1016. Brewfather tells me I have at this rate a brewhouse efficiency of 61%, attenuation 59% and ABV 3.2%. FV currently running about 21C. What’s going on?!
My thoughts so far: 1. I didn’t get enough sugars out of the bag at mash out. I squeezed as much as I could with bare (sanitised) hands, but was it hot! (Gloves now on order.) 2. Should have mashed for longer; I did an hour at 66C though Finch’s general advice is up to an hour and a half. 3. Final volume in FV was 20.5L for an intended batch of 19L - have I overproduced/diluted? 4. I have no other ideas! So disappointed and thinking should I stick to mashing and sparging in my Brewzilla in future.

 

[fury_tea]

There's a few things that could contribute to this situation. Try to learn from this and rule them out next time.
1. Inaccurate measurements
Did you measure wort at the right temp and if not did you correct for temp?
2. Grain crush
A finer grain crush helps with lower efficiency from BIAB
3. Mash temp
Was your mash a consistent temperature?
Higher temps will extract a less fermentable wort so could be worth doing a step mash if recirculating is possible, 61c and 68c should extract a more fermentable wort with a lower FG

 

[Hazelwood Brewery]

The efficiency isn’t far off where I would expect it. BIAB efficiency is around 65%, brewing systems 75-85%, professional breweries 90-95%. You may have got the extra 4% by mashing for a bit longer.

The issue of attenuation needs more info - what volume of wort are you fermenting, what yeast did you use, how much yeast did you use, what temperature did you pitch at, what temperature did you ferment at, was the temperature stable.

1016 does sound a bit high but you say three days later - have you been fermenting for just 3 days? A lot can happen in 3 days but it takes longer to fully ferment (I allow 12 days for most brews).

 

[RichK]

I've found a couple of things doing BIAB. Temperature can often be a little higher than I thought (a couple of degrees will make a difference) particularly if I'm measuring at the top of the water level). I'm not sure on the accuracy of my thermometer (must get a better one!). A longer mash can help too. I tried 45 & 60 mins but got similarly low results - now I do a minimum 90 mins or even longer if practical. Finally are you doing any sort of sparge? A simple jug or dunk sparge might help also?

 

[pilgrimhudd]

I BIAB, I intentionally use more grain to poor efficiency if I mash for an hour. However I have now started to mash overnight more regularly and the difference in efficiency is stunning, I haven't worked it out properly but I reckon high 70- low 80%.

Also just as an aside, you say you were bag squeezing with sanitised hands, you don't need to do that if you are boiling the wort after bag squeezing. I sometimes leave mine outside for ages dripping into a bucket to get every last bit!

 

[Seghes]

now I do a minimum 90 mins or even longer if practical. Finally are you doing any sort of sparge?

Thanks. Yes, I will try that. I did a kind of sparge in the Brewzilla using the pump

 

[Sandimas]

The efficiency isn’t far off where I would expect it. BIAB efficiency is around 65%, brewing systems 75-85%, professional breweries 90-95%. You may have got the extra 4% by mashing for a bit longer.

Yes, I get a consistent 68% with BIAB: hour mash followed by a dunk sparge.

The trouble is recipes are often drawn up with a higher efficiency, 70 or 75%, so you need to adjust it for your actual efficiency. Once you've done a few brews, you'll work out what that is. Chances are it'll be lower than many published recipes so you will need more grain to hit the target OG.

1016 after 3 days sounds pretty good but it isn't finished yet, many of us ferment for at least 2 weeks or longer, I usually bottle between days 20-30.

 

[Seghes]

I BIAB, I intentionally use more grain to poor efficiency if I mash for an hour. However I have now started to mash overnight more regularly and the difference in efficiency is stunning, I haven't worked it out properly but I reckon high 70- low 80%.

Also just as an aside, you say you were bag squeezing with sanitised hands, you don't need to do that if you are boiling the wort after bag squeezing. I sometimes leave mine outside for ages dripping into a bucket to get every last bit!

Wow, can’t argue with those results! Of course you’re right about the hands business - beginners forgetfulness.

 

[Seghes]

There's a few things that could contribute to this situation. Try to learn from this and rule them out next time.
1. Inaccurate measurements
Did you measure wort at the right temp and if not did you correct for temp?
2. Grain crush
A finer grain crush helps with lower efficiency from BIAB
3. Mash temp
Was your mash a consistent temperature?
Higher temps will extract a less fermentable wort so could be worth doing a step mash if recirculating is possible, 61c and 68c should extract a more fermentable wort with a lower FG

Thanks for your response. Yes to 1 and 3. For 2, Don't know how fine is was - tho I trust Malt Miller. Don’t you mean fine crush=higher efficiency?

 

[Seghes]

BIAB efficiency is around 65%

Didn’t know that, thanks. Re wort and yeast, I followed Jon Finch exactly. Yes, reckon I need leave the ferment for quite a bit longer.

 

[Seghes]

1016 after 3 days sounds pretty good but it isn't finished yet, many of us ferment for at least 2 weeks or longer, I usually bottle between days 20-30.

This a bit that confuses me. On a previous batch I had the same SG and no bubbling at all for 3 days, even though it was well short of the FG target. I kegged it, even though it was lower ABV than the target. Even with no activity in, say 3 or 4 days do I still leave it?

 

[Sandimas]

This a bit that confuses me. On a previous batch I had the same SG and no bubbling at all for 3 days, even though it was well short of the FG target.

How are you determining that it is finished - by lack of bubbles? This is not recommended, lack of bubbles does not mean it's finished, you need to take hydrometer readings and when they are consistent 2-3 days apart the brew is finished. No so critical when kegging but if bottling getting it wrong could lead to exploding bottles.

BTW I plugged the figures for the recipe into Brewmate, it's calculated for 76% efficiency, so if I did it with my setup (68%) I'd only get an OG of 1045, your OG of 1040 confirms the 61% efficiency as stated by your Brewfather. If you want to hit the OG with these recipe packs it's worth getting some extra grain, as your setups efficiency will rarely be the same as the one used in the recipe calculator.

 

[Cwrw666]

Last time I checked I was getting an efficiency of 83%. (BIAB)
Grinding my own grains was the biggest thing that helped. Possibly for a fresher product, possibly because I do a finer grind than crushed malt.
Also I do a dunk sparge into about 6L of hot water in an FV. Give it a stir so the water penetrates the mashed grain ball, then hoist it out to drain & give it a squeeze.
I can't see any reason why efficiency would be higher in a 3 tier system than a BIAB system.

 

[Seghes]

Last time I checked I was getting an efficiency of 83%. (BIAB)
Grinding my own grains was the biggest thing that helped. Possibly for a fresher product, possibly because I do a finer grind than crushed malt.
Also I do a dunk sparge into about 6L of hot water in an FV. Give it a stir so the water penetrates the mashed grain ball, then hoist it out to drain & give it a squeeze.
I can't see any reason why efficiency would be higher in a 3 tier system than a BIAB system.

Cracking results and love the tips. Thank you Several have commented on the need for a finer grain. I may start checking out grinders - I really do want to stick with BIAB.

 

[chrisb8]

+1 for overnight mashing.

Even just for the fact that I find splitting the brew day makes it so much easier. Mash in and wrap it up for the night, set up a timer to heat the sparge water and it's all ready to go in the morning

 

[pilgrimhudd]

+1 for overnight mashing.

Even just for the fact that I find splitting the brew day makes it so much easier. Mash in and wrap it up for the night, set up a timer to heat the sparge water and it's all ready to go in the morning

I've also noticed the end product seems to have more body or perhaps just is just better, have you noticed similar?

 

[chrisb8]

Better yes. I currently have a pale ale in the fermenter which is a rebrew of one that was a bit thin first time around so I am hoping to have more body with this one

 

[Seghes]

I like the sound of overnight mashing. Is that with or without heat? Or is it, say heat for an hour or so then leave to soak overnight?

 

[pilgrimhudd]

I like the sound of overnight mashing. Is that with or without heat? Or is it, say heat for an hour or so then leave to soak overnight?

No it's on the heat all night, my klarstein isn't deadly accurate so you have to be ok with temp fluctuations of around 3-4c.

 

[GeorgieV]

To the original post, @Seghes if you are not happy with the ABV, the easiest solution is to add some sugar during the fermentation (preferably towards the end) to compensate for the missed OG.

Regarding the mash time, I don't rely on the recipe time as the circumstances vary a lot. I use iodine tincture test to check if the conversion is complete. Sometimes 60 min. is okay but often it takes about 75 minutes for the conversion to be completed.

I haven't tried an overnight mash but sounds very attractive.