I did my second BIAB on Sunday and put it into the fermenter today. It was an American Amber Ale and I unashamedly stole the recipe from somewhere on this forum (thanks to the author). I ran it through the Calculator and away I went. Upped my strike temp from last time and started the mash at 67deg C. Mashed for 90 mins and finished at 66 deg. Pat on back. SG at the start of the boil was 1040 (if I can believe the converter I used, from a site called Brewmate) as opposed the the Calc which said 1037. Not too worried. Volume at start of mash agreed with the Calc - 38 litres. Did a 90 min boil and noticed later that the recipe said a 60 min boil. Ended up with the right volume - 26.5 litres. According to the Calculator the end of boil gravity should be 1054. Checked it today when I put it in the fermenter and it was 1042. A little bit concerned now but will not be unhappy with a lower strenght beer.
I use a 40 litre Crown urn with a diameter of 33cm. I used 4.89kg of grain, as specified by the recipe for a 21 litre batch size. After the boil I whirlpooled and let it sit for 20mins, then put it into a Willow cube. When I squeezed the air out the cube took a bow and crumpled a bit at the front. I took a photo but it is too big to post here. Anyway the cube straightened out when I tipped it on it's side.
I guess that my main concerns are:
why such a large discrepancy in the end of boil gravity, and
should I wait longer before pouring the wort into the cube, or could this just have been an imperfection in that particular cube?
Post #2 made 15 years ago
Firstly, well done on getting your second BIAB done 
With the weight of grain, I'd consider your OG to be pretty close to spot on, if anything a point or 2 low. It's around what I use and my beers are all around 1046.
I wouldn't worry about the cube. I generally only have mine off the boil 5 minutes before going into the cube and have never had a problem. That said mine are not willow, they are from Aussie disposals $15 each.
As for the discrepancy, Pistolpatch would be the one to talk to. Send him a pm if you feel the need.
With the weight of grain, I'd consider your OG to be pretty close to spot on, if anything a point or 2 low. It's around what I use and my beers are all around 1046.
I wouldn't worry about the cube. I generally only have mine off the boil 5 minutes before going into the cube and have never had a problem. That said mine are not willow, they are from Aussie disposals $15 each.
As for the discrepancy, Pistolpatch would be the one to talk to. Send him a pm if you feel the need.
"It's beer Jim, but not as we know it."
Post #3 made 15 years ago
[LOL hashie, just read your post after writing the below .]
Hiya Bob,
Mate, first thing is I wouldn't be worried at all. If you search this site for posts of mine with the word, "hydrometer," in them, you're bound to find many examples and rambles about how not to trust a single reading. Dodgy readings are more likely to occur once the wort is out of the kettle - more chance of trub etc clinging etc etc. Refractometer readings are also often less reliable than hydrometers due to the small sample size.
Here's a trick for you...
Make sure you buy a decent hydrometer tube i.e. a wide one that allows your hydrometer plenty of room. Most tubes supplied with hydrometers are pretty bad - way too narrow. After you have pitched your yeast into the fermenter and aerated it, take a hydrometer sample, put the hydrometer in it and sit the sample beside your fermenter through the entire ferment. (If possible, cover it so stuff can't fall in.) Doing this will enable you to watch the gravity slowly change and also observe the different stages of fermentation including its completion.
So, I seriously wouldn't be worried about a single reading. If you used the right amount of grain (would need to see the original recipe to know for sure) then it is bery hard to end up with a low gravity beer.
There is a very small possibility that your wort became infected in the cube and started fermenting straight away. If this was the case and the beer suddenly dropped ten gravity points, you would expect the cube to swell significantly, or, if it wasn't air-tight, for their to be no sudden intake of air when you opened the cube. Pretty unlikely.
Can't help you on the cube bending but if you have a large pic that you want to post here, you can use a program such as Microsoft Office Picture Manager to resize it for forums. Alternatively you can use an online tool such as ImageShack. Play around with one of these and don't be worried if you make a mistake as you can always edit your post and try again until you get it right.
Cheers mate,
PP
.]Hiya Bob,
Mate, first thing is I wouldn't be worried at all. If you search this site for posts of mine with the word, "hydrometer," in them, you're bound to find many examples and rambles about how not to trust a single reading. Dodgy readings are more likely to occur once the wort is out of the kettle - more chance of trub etc clinging etc etc. Refractometer readings are also often less reliable than hydrometers due to the small sample size.
Here's a trick for you...
Make sure you buy a decent hydrometer tube i.e. a wide one that allows your hydrometer plenty of room. Most tubes supplied with hydrometers are pretty bad - way too narrow. After you have pitched your yeast into the fermenter and aerated it, take a hydrometer sample, put the hydrometer in it and sit the sample beside your fermenter through the entire ferment. (If possible, cover it so stuff can't fall in.) Doing this will enable you to watch the gravity slowly change and also observe the different stages of fermentation including its completion.
So, I seriously wouldn't be worried about a single reading. If you used the right amount of grain (would need to see the original recipe to know for sure) then it is bery hard to end up with a low gravity beer.
There is a very small possibility that your wort became infected in the cube and started fermenting straight away. If this was the case and the beer suddenly dropped ten gravity points, you would expect the cube to swell significantly, or, if it wasn't air-tight, for their to be no sudden intake of air when you opened the cube. Pretty unlikely.
Can't help you on the cube bending but if you have a large pic that you want to post here, you can use a program such as Microsoft Office Picture Manager to resize it for forums. Alternatively you can use an online tool such as ImageShack. Play around with one of these and don't be worried if you make a mistake as you can always edit your post and try again until you get it right.
Cheers mate,
PP
Last edited by PistolPatch on 23 Nov 2010, 16:29, edited 5 times in total.
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Post #4 made 15 years ago
Thanks PP. I have got a good sized hydrometer tube. I kegged this brew today. My procedure is to pour some brew into a jug to clear the crap out of the tap, then take a sample for FG. Came out at 1008 which was OK, if not slightly higher ABV than I would like. I just left the hydrometer in the tube and about half an hour later noticed the reading was 1022. I tapped the tube and swirled the hydrometer around in an attempt to get rid of any bubbles, left it for a few minutes and the reading was back to 1008. Anyhow, it tasted OK, now to cool it down and carbonate.PistolPatch wrote:[LOL hashie, just read your post after writing the below
Make sure you buy a decent hydrometer tube i.e. a wide one that allows your hydrometer plenty of room. Most tubes supplied with hydrometers are pretty bad - way too narrow. After you have pitched your yeast into the fermenter and aerated it, take a hydrometer sample, put the hydrometer in it and sit the sample beside your fermenter through the entire ferment. (If possible, cover it so stuff can't fall in.) Doing this will enable you to watch the gravity slowly change and also observe the different stages of fermentation including its completion.
Cheers mate,
PP
Bob
Last edited by BobtheBrewer on 09 Dec 2010, 17:41, edited 5 times in total.
