Help - First Full Grain BIAB and I have low OG

[HeavensBrew]

First attempt at a full grain recipe using BIAB... and I have learned a few lessons.

I was trying to make a Kona BIg Wave Clone today, but I have discovered my OG is only 1.032. I would have expected 1.040 or more.

So....should I
1) Continue as it stands? Will I end up with super low ABV?
2) Add some DME? Potentially that would be Monday!
3) Do something else?

All advice appreciated.

 

[Madhouse]

Hi. Well according to that OG you will have a low abv beer but that doesn’t mean it’ll be a bad beer.
If you want to up the abv then you could just add any kind of sugar, basically anything the yeast can eat. You could even turn it into something fruity with mango & passion fruit juice! (Other juices are available).

More importantly you want to work out what went wrong. How were your calculations? Did you have more or less wort than you were expecting?

 

[DavidDetroit]

You could leave it as was mentioned. Sugar would dry it out but is an option.
Personally, I would add 3/4 of the yeast now to get it fermenting, add DME on Monday with the proper percentage of yeast remaining.

 

[HeavensBrew]

Thanks. My lessons learned so far on this topic are:
1) I need to improve my sparging system - I was doing the BIAB in a Peco boiler and only topped the water up before the boil. After that I was draining out a few jugs and adding them to the top, but no real sparging. I need to learn more about obtaining efficiency with BIAB.
2) I need to check OG more often and so I will order a refractometer. In this case I had less wort than expected and simply added more water without checking the OG.
I did not check the OG first as I do not have a Wort Chiller and it was too hot.

 

[HeavensBrew]

Target ABV was 4.46% and the accurate OG should have been 1.044. That makes me 12 points out. If I hit the target FG of 1.010, the beer would then be 2.89%. At such a low ABC, perhaps an intervention with DME would be for the best.

I will go for DME as I want to test the overall flavour of the recipe. Seems it is the summer brew of choice for many.

To reach the target OG I calculate 587g of DME is required. Maths below:
(((1044 target OG -1032 actual OG) x 5 gallons) / 46 for DME) x 450g

I have 500g of DME due on Monday and plan to follow David Detroits idea, unless new info arrives this morning.

 

[Brew_DD2]

Thanks. My lessons learned so far on this topic are:
1) I need to improve my sparging system - I was doing the BIAB in a Peco boiler and only topped the water up before the boil. After that I was draining out a few jugs and adding them to the top, but no real sparging. I need to learn more about obtaining efficiency with BIAB.
2) I need to check OG more often and so I will order a refractometer. In this case I had less wort than expected and simply added more water without checking the OG.
I did not check the OG first as I do not have a Wort Chiller and it was too hot.

I'd be checking grain crush and the water volumes you need for your system.

These recipe kits also assume a certain brewhouse efficiency, which often BIABers often fall below. Try not to see efficiency as something you're doing wrong, it's just a case of getting to know your equipment and dialling in the amount of grain and water you need to hit your target gravities.

 

[An Ankoù]

What was you recipe (grains only, hops don't add to OG) and for what batch volume?
The reason I ask is that the Kona website gives the original gravity as 10.3 degrees P for this beer, which could easily be misconstrued as 1030 OG instead of the 1041 it should be.

 

[foxbat]

Target ABV was 4.46% and the accurate OG should have been 1.044. That makes me 12 points out. If I hit the target FG of 1.010, the beer would then be 2.89%. At such a low ABC, perhaps an intervention with DME would be for the best.

I will go for DME as I want to test the overall flavour of the recipe. Seems it is the summer brew of choice for many.

To reach the target OG I calculate 587g of DME is required. Maths below:
(((1044 target OG -1032 actual OG) x 5 gallons) / 46 for DME) x 450g

I have 500g of DME due on Monday and plan to follow David Detroits idea, unless new info arrives this morning.

That's a good plan. The gravity addition from the sugar is quite a large proportion of the overall gravity and DME will have the malt flavours that other sugars would not, preventing your beer from tasting 'thin'.

 

[MickDundee]

These recipe kits also assume a certain brewhouse efficiency, which often BIABers often fall below. Try not to see efficiency as something you're doing wrong,

This is pretty much what I was going to say. A lot of grain kits and recipes assume 70%+ efficiency and I know that before I got my Brewdevil my BIAB method was getting me 65% no matter what I did.

There are little things like pouring the grain in very slowly and stirring constantly whilst mashing in that might get you a few percentage points but there’s no point reinventing the wheel to gain a few points when it’s probably the equivalent of needing to add about 20p worth of extra grain.

 

[HeavensBrew]

What was you recipe (grains only, hops don't add to OG) and for what batch volume?
The reason I ask is that the Kona website gives the original gravity as 10.3 degrees P for this beer, which could easily be misconstrued as 1030 OG instead of the 1041 it should be.

21L batch - 3.4kg Pale and 680g of Caramel.
Recipe found on another forum from a google search and had proved to be quite popular

 

[Galena]

I made this mistake myself, the answer when it does go wrong I think is if you check your OG with about 10 or 15 to go in the boil, if your SG is too low then use an online calculator to decide whether to boil it off further or add DME to get you at the correct OG. Brewfather has a great calculator that will work this out for you. Alternatively if your SG is too high then calculate how much water to add.
I found with BIAB I was not getting great mash efficiency but improved it by constantly recirculating by hand during the mash and monitoring temperature using a digital thermometer. Dropping the first runnings into a bucket and doing a full batch sparge, stirring well and allowing 5 minutes with some stirring and then putting both back into the kettle for the boil.
This VIDEO is also useful

 

[Madhouse]

Refractometers are great for constant checking, just need to get the wort to 20ish degrees each time, but that doesn't take lond for the size of the sample you'll be taking.

Getting your efficiency and water volumes right in your calculator will take a little while and some tweaking. But exxentially it's FV volume + water lost to grain + boil off. Not saying my own calculations are right but they do work for me!

By the look of that malt bill I'd say your issue is the efficiency in the recipe. I know my efficiency's low, but I've used a 3kg malt bill for a 10L batch.

 

[PhilBrew]

Hi @HeavensBrew

21L batch - 3.4kg Pale and 680g of Caramel.
Recipe found on another forum from a google search and had proved to be quite popular

Was that recipe to make 5 imperial (UK) gallons (roughly 23 lts) ... or 5 US gallons (around 19 lts)?
And how much did you actually get into your FV?

Cheers, PhilB

 

[HeavensBrew]

I probably should have started with a recipe I have for Grumpy Troll Belgian DIPA. That has a targeted 10% ABV and so losing a couple of percent would not be a deal breaker.

Maybe a first newbie brew should be a higher ABV for that reason.

 

[HeavensBrew]

Hi @HeavensBrew

Was that recipe to make 5 imperial (UK) gallons (roughly 23 lts) ... or 5 US gallons (around 19 lts)?
And how much did you actually get into your FV?

Cheers, PhilB

5.5 US Gallons, so about 21L.
1) I started with 23L in the Peco boiler for a 60 minute mash. That was a pure guess.
2) I then topped it up once I took the grain out and set the Peco to boil for 60 mins. Boiling in a Peco is done with a loose lid. As opposed to a converted cooler or an enclosed system, this does increase the boil off.
3) Before I screwed it up by adding more water to the FV, I had about 18.8L in the FV

Loads of mistakes and lessons learned.

 

[ChrisT685]

I've just done my first AG BIAB using a Peco boiler and according to calcs managed to hit 70% which was definitely through luck and not judgement, I'm sure.

As others have said, I moved the grain around at least 4 times during the mash and had a digital thermometer through the lid of the boiler and kept temp constant using an old puffer jacket.

I dunk sparged for 15 minutes also which gave me my boil volume without needing to top up with plain water.

I wasn't seeing as much loss as I thought I would during the boil so I ended up booking for 90 minutes which I think helped hit OG.

Don't know if any of that helped at all?

 

[An Ankoù]

21L batch - 3.4kg Pale and 680g of Caramel.
Recipe found on another forum from a google search and had proved to be quite popular

That looks about right. I don't know about BIAB because I always sparge, but with a full sparge I'd expect that to come out at around 1047 OG. Sorry that's little help, but it was worth eliminating that possibility.

 

[HeavensBrew]

I've just done my first AG BIAB using a Peco boiler and according to calcs managed to hit 70% which was definitely through luck and not judgement, I'm sure.

As others have said, I moved the grain around at least 4 times during the mash and had a digital thermometer through the lid of the boiler and kept temp constant using an old puffer jacket.

I dunk sparged for 15 minutes also which gave me my boil volume without needing to top up with plain water.

I wasn't seeing as much loss as I thought I would during the boil so I ended up booking for 90 minutes which I think helped hit OG.

Don't know if any of that helped at all?

1) Did you put all your water in at the beginning or add more at any point later?
2) How much water did you start with and how much wort did that end up with? Basically, how much water did you boil off?
3) I set the Peco for 97 for the boil. Did you switch yours off instead as you maintained the heat with the puffer jacket?

4) When you say, 'dunk sparged for 15 min', were you constantly dunking it in and out? I do need to rig something up as I got bored holding the bag.

 

[ChrisT685]

1) Did you put all your water in at the beginning or add more at any point later?
2) How much water did you start with and how much wort did that end up with? Basically, how much water did you boil off?
3) I set the Peco for 97 for the boil. Did you switch yours off instead as you maintained the heat with the puffer jacket?

4) When you say, 'dunk sparged for 15 min', were you constantly dunking it in and out? I do need to rig something up as I got bored holding the bag.

To get a pre boil volume of 28L I started with 33L which was split between 20L mash and 13L sparge. Grain bill for my recipe was 6kg so a lot of grain absorption.

28L into the boil left me with 23L after 90 mins and I kept the boiler on throughout. I used the puffer jacket to maintain temp for the mash at 65 degrees.

My dunk sparge was literally sitting the bag in a spare FV for 15 mins and then pulling it out and lightly squeezing it using an oven rack (tip picked up from the forums - thank you!) to take the weight of the bag.

Hope that helps - sorry if my post confused !

 

[terrym]

Others have mentioned brew house efficiency which seems to vary from brewer to brewer, however they brew.
https://www.thehomebrewforum.co.uk/threads/ag-brewhouse-efficiency-what-do-you-get.87273/I do small volume stove top BIAB and was amazed to find that by making a few simple adjustments to the way I extracted malt liquor from the mashed grain (inc. larger mash and sparge volumes, and more bag draining squeezing) I got a significant improvement to my BH efficiency.
Anyway, it might be worth looking through the above thread for tips on how to improve your efficiency in addition to those suggestion folks have offered here