First AG BIAB brew - problems!

The Homebrew Forum

Help Support The Homebrew Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

BrewJas

New Member
Joined
May 18, 2020
Messages
14
Reaction score
11
Location
Perth, Scotland
Just brewed my first ever AG brew using BIAB. Mash and boil all went as planned, estimated pre-boil gravity hit. It all got a bit chaotic at the end though as I forgot to take an OG before transferring wort to fermentation bucket and aerating it, and think I rehydrated my yeast too early.

Problem 1 - only 8L made it to the FV, I expected 11L from 15L pre mash. I think I lost a lot to the boil but no idea how much. I think I also lost at least 1 L mucking about with a ladle trying to take gravity readings! I also poured the wort through a sieve when putting it in th FV which collect a load of trub. I put a wee bit back in the FV to help the yeast but should I have put it all in the FV?

Problem 2 - not sure my yeast rehydrated correctly. I cooled boiled water in a Pyrex jug to 25C, added powder, left for 15-20 with cling film on, then stirred. Probably left is about 45 mins or so before pitching. Didn’t see any cake on top, just a cloudy liquid. Do you think this will work? If not I have a spare US-05 packet of yeast, could I add this after 24 hours if no activity in the FV?

Problem 3 - original gravity looked like 1.051 when it should have been 1.041. This sample was taken from FV after aeration so was a right mess. Can I add some water to the FV to dilute it down, and if so, how do I calculate how much to do?

lots of learnings and fingers crossed I get something drinkable at the end of it all!

thanks
Jason
 
Hi Jason, first of all did you add the yeast and then aerate the wort or did you aerate and take the sample without the yeast?

Problem 1. Did you account for any dead losses in your system (if you have any) also did you use enough strike/sparge water?

Problem 2. All you've done is rehydrate the yeast so no cake will form as you didn't add any fermentables (as in a starter) and the yeast will do it's job OK.

Problem 3. What's the problem with hitting a higher OG just means your beer will be a tad stronger

Tip: I use a big turkey baster ( unused for turkey and sanitised) to draw of the wort for my OG reading.

Take it easy and have a beer, things will be fine.
 
Wait for 48hrs or so from pitching and if you see a sort of dark ring just above the level of the liquid in the FV, all is well. Newbie gravity readings are about as much use as a horoscope in a daily newspaper, to be quite honest.

As for the water, I reckon on 36L for mash and sparge to get 25L post boil. Suggest you just use more water for the sparge. If it's a dunk sparge, stirring the grain a bit might help and running some more water through the bag is another idea to get more out of the grain and ensure you get more wort.

Don't fret overly about the first time you follow any new process. As you say, next time will be better.
 
Hi Banbeer

I aerated without yeast then tried to take a sample using a ladle but it was extremely frothed up and a complete mess using the ladle. Think I need a turkey Baster or wine thief.


Not sure I understand about dead loss in the system. I have a 19L pan so did a full mash with no sparge. I factored in boil and grain losses to get to 15L mash volume but don’t think it was enough. Sparging seems more complicated so thought it stick to mash with no sparge.

So you don’t think I should dilute the wort? As long as it ferments I suppose I shouldn’t care don’t what the percentage is!
 
Wait for 48hrs or so from pitching and if you see a sort of dark ring just above the level of the liquid in the FV, all is well. Newbie gravity readings are about as much use as a horoscope in a daily newspaper, to be quite honest.

As for the water, I reckon on 36L for mash and sparge to get 25L post boil. Suggest you just use more water for the sparge. If it's a dunk sparge, stirring the grain a bit might help and running some more water through the bag is another idea to get more out of the grain and ensure you get more wort.

Don't fret overly about the first time you follow any new process. As you say, next time will be better.
Thanks Slid, I was trying to do a small batch to avoid sparging but with the effort involved I want to end up with a few beers so will need to looking it.
 
Just brewed my first ever AG brew using BIAB. Mash and boil all went as planned, estimated pre-boil gravity hit. It all got a bit chaotic at the end though as I forgot to take an OG before transferring wort to fermentation bucket and aerating it, and think I rehydrated my yeast too early.

Problem 1 - only 8L made it to the FV, I expected 11L from 15L pre mash. I think I lost a lot to the boil but no idea how much. I think I also lost at least 1 L mucking about with a ladle trying to take gravity readings! I also poured the wort through a sieve when putting it in th FV which collect a load of trub. I put a wee bit back in the FV to help the yeast but should I have put it all in the FV?

Problem 2 - not sure my yeast rehydrated correctly. I cooled boiled water in a Pyrex jug to 25C, added powder, left for 15-20 with cling film on, then stirred. Probably left is about 45 mins or so before pitching. Didn’t see any cake on top, just a cloudy liquid. Do you think this will work? If not I have a spare US-05 packet of yeast, could I add this after 24 hours if no activity in the FV?

Problem 3 - original gravity looked like 1.051 when it should have been 1.041. This sample was taken from FV after aeration so was a right mess. Can I add some water to the FV to dilute it down, and if so, how do I calculate how much to do?

lots of learnings and fingers crossed I get something drinkable at the end of it all!

thanks
Jason
Hey Jason,
It sounds like things will be fine. Did you adjust the gravity reading for temperature? If so, and you ended up with genuinely stronger wort than intended, it sounds like you just had a higher boil-off than expected and concentrated the wort more than predicted. This is good! It means next time you can add more water (either in the mash or sparge if you like) which will give you more wort of a lower gravity.
 
A bottling wand can make a good wine thief for samples. Sanitise one and insert upside down into wort , pump the wand button and then withdraw, the wand will have some wort in it . I do this two or three times for a sample for testing
 
Back
Top