Strained all grain wort into fermenter, got a MUCH lower OG than expected

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peroua15

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Making a belgian tripel, used all grain mash at 154 for an hour. boiled and hour, and chilling took about 45 minutes. i used a paint bag strainer to strain into my fermenter. there looked like a lot of sediment was in the paint bag. turns out my OG is about 1.035 where i was expecting it closer to 1.070....is this due to me removing all of that trub and crap during the strain. I'd like to know what i did wrong and what to do differently next time. maybe just use liquid extract instead would be easier. i did that last time and had perfect OG and only a little think stuff in my paint strainer....help me.
 

kh54s10

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Not at all due to straining. The sugars would not be stopped by the strainer bag.

Being that far off I have 2 things in mind. Was there any top up water added? If so it is likely that the wort did not mix well and you measured a weak sample. With all grain, and no top up, either your amounts were wrong or you had a very bad crush or the grain was not crushed at all.
 

kh54s10

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You will probably need to post the recipe and give some more details on your processes to help determine where the problem occurred.
 

MindenMan

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I agree, the only thing straining could have done was reduce wort volume, not the strength of the wort.
 

Beernik

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That's not a trub problem. If it's not a partial boil, that seems like a bad crush or efficiency problem. Either water wasn't getting to the grain in the interior of your BIAB bag or your grain wasn't crushed enough to extract enough of the sugars.

A lot of the guys on here use a mill their grains twice for BIAB.

With all grain, you want to pull a hydro sample after you mash and check the pre-boil gravity. It should be 70% - 80% of your anticipated OG, depending on how much boil off you get.
 
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peroua15

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I used a different paint bag to mash with. water was flowing through it and soaking up all the grains (so it seemed) the boil took more water out than I had anticipated. so I had to top off with about a gallon and a half of water....could this possibly be the problem.
 

kh54s10

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I used a different paint bag to mash with. water was flowing through it and soaking up all the grains (so it seemed) the boil took more water out than I had anticipated. so I had to top off with about a gallon and a half of water....could this possibly be the problem.
The top up water was likely the problem. How long since you pitched the yeast? If it has not started fermenting you can take another reading to find out.

If your efficiency was low, possibly due to a coarse crush or dough balls, your OG would have been low to start with. Boiling off too much would have raised the gravity some, then adding water would have lowered it again.

If everything was good and you boiled away too much your gravity would have been high and water would have brought it back to the proper OG.
 
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peroua15

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The top up water was likely the problem. How long since you pitched the yeast? If it has not started fermenting you can take another reading to find out.

If your efficiency was low, possibly due to a coarse crush or dough balls, your OG would have been low to start with. Boiling off too much would have raised the gravity some, then adding water would have lowered it again.

If everything was good and you boiled away too much your gravity would have been high and water would have brought it back to the proper OG.
I think you are right. it's likely the top off water. The recipe was SUPPOSED to be at a starting gravity of around 1.075ish. I followed it accordingly so would it be safe to use this to give a rough estimation of alcohol percentage when all is done?
also, its been in the fermenter about an hour now. I just don't want to mess with it, was more worried about if i messed up the mashing or straining process. the alcohol content is negligible. I am more concerned with the overall taste of the beer at the end of the day.
 

Beernik

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I agree. If you topped off, it's probably just a bad sample. I've had bad samples work both ways. Some trubby samples reading too high and other top-off samples reading too low because of incomplete mixing.
 

acidrain

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With BIAB, you need to squeeze all the wort out. When I was doing BIAB, I mashed at full volume and did not sparge and was consistantly getting 80% efficiency.
You say you boiled away more than expected. Your boil off rate is very important. You need to know what it is and plan accordingly.
Live and learn... next time factor in the boil off rate when calculating your starting and sparging volumes.
 
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peroua15

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With BIAB, you need to squeeze all the wort out. When I was doing BIAB, I mashed at full volume and did not sparge and was consistantly getting 80% efficiency.
You say you boiled away more than expected. Your boil off rate is very important. You need to know what it is and plan accordingly.
Live and learn... next time factor in the boil off rate when calculating your starting and sparging volumes.
so are you saying I need to know how much water will boil off to get a good efficiency due to the 'water being fully saturated' and no more sugars to be made...? if i have more water, that means more sugars, meaning a higher OG and thus higher efficiancy...? right?
 
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peroua15

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also as you may have caught on I am new to the all grain brewing. I was thinking about the batch the other day and realized that my mash temp rose to about 175- 180 for about 10 minutes. This was about 30 minutes or so into the mash process. would this halt enzyme conversion. would this have given me a lower OG than expected? before I suspected it was the top water and poor mixing of it before taking a sample, but now I'm second guessing....
 
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