gravities

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rodneygullick
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gravities

Post by rodneygullick »

I've just done a brew 1.5 mash 1 hour boil @105-6degsC I haven't really took much notice of it before but I thought I would check the some of the gravities, I noticed that pre boil was exactly the same as end of boil I started with 28.2 low ended up with 22.5 l surly the gravity should have been higher perhaps I am doing something wrong any ideas Rodney
PMowdes
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Re: gravities

Post by PMowdes »

Do you know what temperature you took your gravity readings at?

Density (which is what you are measuring) if affected by temperature.

Your hydrometer will be calibrated to a specific temperature (usually 20 degress Celcius)

You need to correct any gravity reading to the temperature of your sample.
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PMowdes
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Re: gravities

Post by PMowdes »

Also if you are boiling at 105 -106 degrees you might want to get your thermometer checked.

You shouldn't be able to get much above 100 degrees in principle.
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rodneygullick
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Re: gravities

Post by rodneygullick »

pre boil i took it down to 20c i ran it from the boiler into a glass and stood it in cold water for about 1/2 hour then i put it into my hydrometer jar and cooled it again , i was afraid that the water from the boiler might melt the jar, i done a check from the fv for final gravity ,the recipy said pre boil 1044 final gravity 1052 , i made it 1048 both times
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Jeltz69
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Re: gravities

Post by Jeltz69 »

rodneygullick wrote:I've just done a brew 1.5 mash 1 hour boil @105-6degsC I haven't really took much notice of it before but I thought I would check the some of the gravities, I noticed that pre boil was exactly the same as end of boil I started with 28.2 low ended up with 22.5 l surly the gravity should have been higher perhaps I am doing something wrong any ideas Rodney
something is wrong with your readings, it isn't possible to evaporate 5+ litres and have the same sg reading as what is evaporated is water so the sugars will become more concentrated.
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Taz Ales
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Re: gravities

Post by Taz Ales »

It's possible that the pre-boil liquid wasn't mixed well enough, and you managed to get a particularly strong concentration in the measuring cylinder.

Aside from stirring vigorously, I can thoroughly recommend spending around 25 quid for a Refractometer. 3 drops of liquid for testing... it makes life much easier, especially for checking the gravity of your run-off. If you do get one, make sure it's ATC and gives readings in Brix from 0% to around 30%. Most brewing software will deal with conversion to gravity.

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Capn Ahab
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Re: gravities

Post by Capn Ahab »

I've got an atc refractometer that reads both brix and sg - no conversion necessary. Best off looking for one o they.
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Taz Ales
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Re: gravities

Post by Taz Ales »

True, but you do still need to do some correction for post-fermentation.
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Capn Ahab
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Re: gravities

Post by Capn Ahab »

Taz Ales wrote:True, but you do still need to do some correction for post-fermentation.
You're right of course, but I use my hydrometer post fermentation.

In answer to Rodney, I think Taz is on to something regarding the wort not being mixed (stratified) pre-boil.
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mrlard
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Re: gravities

Post by mrlard »

Capn Ahab wrote:I've got an atc refractometer that reads both brix and sg - no conversion necessary. Best off looking for one o they.

what do you make of the ATC refac?
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