Author Topic: 10-gal Batch with 2 different OG's  (Read 2514 times)

Offline In The Sand

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10-gal Batch with 2 different OG's
« on: February 16, 2013, 12:04:23 PM »
Did a compilation yesterday with my brew buddy. Split an apricot IPA. His OG was 1.060 and mine was 1.053. Both our hydrometers are calibrated and he actually checked with 2 different ones.

Our grain bill was 22 lbs 2-row and 1 lb C60. Boiled for 90 min. Anyone know what the cause could be?
Trey W.

Offline Rhoobarb

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Re: 10-gal Batch with 2 different OG's
« Reply #1 on: February 16, 2013, 12:51:37 PM »
Brewed on the two different systems?
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Offline In The Sand

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10-gal Batch with 2 different OG's
« Reply #2 on: February 16, 2013, 01:06:46 PM »
Nope. All one boil.
Trey W.

Offline malzig

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Re: 10-gal Batch with 2 different OG's
« Reply #3 on: February 17, 2013, 09:57:22 AM »
When did you split into two batches?  Did you split the grain into two mashes or the wort into two kettles?

I assume the first, since the second would have to have the same OG.  The first would have two different OGs because you're two systems have two different efficiencies.  Things like dead volume, sparge volume, mash thickness, mash time and mash temperatures can all affect the efficiency from an otherwise identical bag of crushed grain.  That is assuming you split grain from the same crush, otherwise, crush tends to be the overwhelming variable.

Offline In The Sand

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10-gal Batch with 2 different OG's
« Reply #4 on: February 17, 2013, 11:09:45 AM »
When did you split into two batches?  Did you split the grain into two mashes or the wort into two kettles?

I assume the first, since the second would have to have the same OG.  The first would have two different OGs because you're two systems have two different efficiencies.  Things like dead volume, sparge volume, mash thickness, mash time and mash temperatures can all affect the efficiency from an otherwise identical bag of crushed grain.  That is assuming you split grain from the same crush, otherwise, crush tends to be the overwhelming variable.

It was all together. Same mash, same crush, same boil. The place it was separated was into 2 carboys for fermentation. It was a 10 gallon batch. Full boil.
Trey W.

Offline denny

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Re: 10-gal Batch with 2 different OG's
« Reply #5 on: February 17, 2013, 11:39:17 AM »
When did you split into two batches?  Did you split the grain into two mashes or the wort into two kettles?

I assume the first, since the second would have to have the same OG.  The first would have two different OGs because you're two systems have two different efficiencies.  Things like dead volume, sparge volume, mash thickness, mash time and mash temperatures can all affect the efficiency from an otherwise identical bag of crushed grain.  That is assuming you split grain from the same crush, otherwise, crush tends to be the overwhelming variable.

It was all together. Same mash, same crush, same boil. The place it was separated was into 2 carboys for fermentation. It was a 10 gallon batch. Full boil.

Something's gotta be wrong because that's nearly impossible.
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Re: 10-gal Batch with 2 different OG's
« Reply #6 on: February 17, 2013, 11:52:13 AM »
Were they chilled separately? If so, it's possible that one batch had more evaporation occur than the other. If not, one of the hydrometer readings is wrong.
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Offline In The Sand

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10-gal Batch with 2 different OG's
« Reply #7 on: February 17, 2013, 11:55:24 AM »
When did you split into two batches?  Did you split the grain into two mashes or the wort into two kettles?

I assume the first, since the second would have to have the same OG.  The first would have two different OGs because you're two systems have two different efficiencies.  Things like dead volume, sparge volume, mash thickness, mash time and mash temperatures can all affect the efficiency from an otherwise identical bag of crushed grain.  That is assuming you split grain from the same crush, otherwise, crush tends to be the overwhelming variable.

It was all together. Same mash, same crush, same boil. The place it was separated was into 2 carboys for fermentation. It was a 10 gallon batch. Full boil.

Something's gotta be wrong because that's nearly impossible.

That's what I'm thinking. Is it possible that the higher gravity portion would sink to the bottom? That's where his came from and mine came from the top.  You wouldn't think so though after a 90-minute boil.
Trey W.

Offline In The Sand

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10-gal Batch with 2 different OG's
« Reply #8 on: February 17, 2013, 11:55:53 AM »
Were they chilled separately? If so, it's possible that one batch had more evaporation occur than the other. If not, one of the hydrometer readings is wrong.

They were chilled together. IC in the BK.
Trey W.

Offline a10t2

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Re: 10-gal Batch with 2 different OG's
« Reply #9 on: February 17, 2013, 11:56:59 AM »
Is it possible that the higher gravity portion would sink to the bottom?

No way. One of your hydrometers is wrong, period. If they both check out at 0, do a two-point calibration.
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Offline denny

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Re: 10-gal Batch with 2 different OG's
« Reply #10 on: February 17, 2013, 12:06:07 PM »
That's what I'm thinking. Is it possible that the higher gravity portion would sink to the bottom? That's where his came from and mine came from the top.  You wouldn't think so though after a 90-minute boil.

It doesn't seem possible and I've never seen it happen to me.
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Offline edward

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Re: 10-gal Batch with 2 different OG's
« Reply #11 on: February 18, 2013, 06:12:54 AM »
Did one of you have a large starter and the other not?

The most obvious solution is that someone diluted theirs with some water.

Offline mtnrockhopper

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Re: 10-gal Batch with 2 different OG's
« Reply #12 on: February 18, 2013, 09:54:58 AM »
That's what I'm thinking. Is it possible that the higher gravity portion would sink to the bottom? That's where his came from and mine came from the top.  You wouldn't think so though after a 90-minute boil.
Only if you added water post chill and didn't stir adequately.  Otherwise, sugar solutions (wort) will never separate once mixed.  Put both hydrometers in the same wort and see if they read the same. Maybe one had some bubbles on it?
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Offline In The Sand

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10-gal Batch with 2 different OG's
« Reply #13 on: February 18, 2013, 10:27:01 AM »
That's what I'm thinking. Is it possible that the higher gravity portion would sink to the bottom? That's where his came from and mine came from the top.  You wouldn't think so though after a 90-minute boil.
Only if you added water post chill and didn't stir adequately.  Otherwise, sugar solutions (wort) will never separate once mixed.  Put both hydrometers in the same wort and see if they read the same. Maybe one had some bubbles on it?

I'll try this. We were not together when we took the readings. Perhaps one of us had too many Hop Slams? I have photo documentation though.
Trey W.

Offline malzig

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Re: 10-gal Batch with 2 different OG's
« Reply #14 on: February 19, 2013, 04:08:26 AM »
Is it possible that the higher gravity portion would sink to the bottom? That's where his came from and mine came from the top.  You wouldn't think so though after a 90-minute boil.
It is surprisingly difficult to mix the two runnings evenly prior to the boil.  That's why I take my "pre-boil" gravity reading right after the wort starts boiling.  It is quite possible that your wort wasn't completely mixed when you split it in two.