Hydrometer Accuracy

[Muscovy_333]

QUESTION FOR SOMEONE.....
After reading a recent post a fellow brewer mentions being over gravity with a turbid wort, and my 'efficiency' has also dropped since recirculating/filtering through the grain bed better.

Does anyone know if the turbidity of a wort can influence the gravity reading. I.e do the floaties potentially affect the density and give a false (or inflated) gravity reading?

I suspect they do, but wanted to know if anyone is aware and do they correct for it...

 

[seamad]

Take a reading with a refractometer and compare

 

[Online Brewing Supplies]

QUESTION FOR SOMEONE.....
After reading a recent post a fellow brewer mentions being over gravity with a turbid wort, and my 'efficiency' has also dropped since recirculating/filtering through the grain bed better.

Does anyone know if the turbidity of a wort can influence the gravity reading. I.e do the floaties potentially affect the density and give a false (or inflated) gravity reading?

I suspect they do, but wanted to know if anyone is aware and do they correct for it...

I believe there is a reason that the manual for brew lab practice (American brewing Chemists) recommend to filter (filter paper in a funnel aka coffee filter) your wort sample before testing.
I did at one stage but now my samples are clear and dont bother.
Nev

 

[Muscovy_333]

I believe there is a reason that the manual for brew lab practice (American brewing Chemists) recommend to filter (filter paper in a funnel aka coffee filter) your wort sample before testing.
I did at one stage but now my samples are clear and dont bother.
Nev

Thanks Nev.
I just did a bit more research since posting and as i suspected the hydrometer is reading the density compared with water. Thus floaties, water composition and mineral additions could all impact hydrometer readings...another reason why brew house efficiency is so arbitary.
My efficiency has taken a hit since HERMs recirc, but i suspect it is now a much more accurate reading.

I have a hydrometer so shall start the comparisons..

 

[bum]

Floaties are not in solution.

 

[Muscovy_333]

Floaties are not in solution.

Do you think that they could still displace water and affect the reading or do you think they are inert?
I'm am trying to get my head around why I have lost 10% efficiency in a drastically improved brew set-up. The only change being recirculating through teh grain bed

 

[bum]

Recipes didn't change? Is your system 100% dialled in? Plenty of places to look before blaming the tools.

 

[Online Brewing Supplies]

Floaties are not in solution.

But the do rest on the hydrometer and drag it down, just as if i sat on your head while you where in the water.
Dont be fooled clear samples work best for accuracy.
Nev

 

[bum]

I can't imagine how turbid wort would need to be to start piling up on top of a hydrometer to blow out a reading so significantly that a brewer should get worried.

Yes, clear wort is best wort.

 

[kelbygreen]

grain crush???
sparge method??
channelling in MT??
amount of sparge water used??

Now grain crush matters a finer crush will be better efficiency, Not sure if its so good in a recirc system or not.

sparge method can play a part. I guess you are fly sparging, Maybe when you start to sparge slow the flow down a bit.

channelling as you are recirculating again if done to fast or the manifold is not done right you will get channelling. slow the recirc and look for signs of channelling when you drained the tun.

amount of sparge water. Now this can help mash with a lower water to grist then sparge with more water this will let you drain more out of the mash but at the end keep a eye on gravity as you dont want to drop below 1.008 I think 1.010 is where most stop. You may need to top up the kettle and adjust for the next brew so you dont have to top up

 

[Muscovy_333]

grain crush??? yep, same as always
sparge method?? manual batch sparge, same as always
channelling in MT?? Will have to investigate this for sure
amount of sparge water used?? same a usual

channelling as you are recirculating again if done to fast or the manifold is not done right you will get channelling. slow the recirc and look for signs of channelling when you drained the tun. Thankyou

amount of sparge water. Now this can help mash with a lower water to grist then sparge with more water this will let you drain more out of the mash but at the end keep a eye on gravity as you dont want to drop below 1.008 I think 1.010 is where most stop. You may need to top up the kettle and adjust for the next brew so you dont have to top up Thankyou

 

[Online Brewing Supplies]

Its a grain (and or bed) bed issue for sure, too drop that many points in one hit.
I lost that before due to trying to get my recirc fast by a course crush, didnt work and lost 10 points of gravity.
Nev

 

[kelbygreen]

I hate to repeat this but why are people batch sparging with a recirc system??? you spend 1 hour setting the bed and filter to stir it all up again! and fly sparging has been proven to give better efficiency. you will have to recirc for 10 mins after each batch sparge to get clear wort why not just fly sparge and not have to recirc and get clear wort the whole way while washing your grain. Plus batch sparging you dont know if you will extract tannins till its to late.

fly sparge and look at your bed after you drain the tun. My manifold would drain more down the furthest point from the output and it would channel. My second last brew was under my gravity and I am always over by a few points I was under by 5 points. Last brew I was over by 5 points. What did I change??? only fly sparged slower. Could of been old grain, not enough grain, bad crush, to fast sparging , wrong water volumes. I dont know but to loose a big deal and gain more is strange for me (although last batch I was under a little so would of been spot on I think if I got targets)

There is so many places to look but this is what I would do if I was you others may disagree but batch sparging in herms??? not sure its wise.

 

[MaltyHops]

I've read that recirc systems are often a bit less efficient than non-recirc systems so for my last brew I tried a method involving draining a good chunk of high grav wort at mash end and replacing with same amount of pH adjusted water for the recirculating rinse to try and improve the efficiency and I think it worked to a significant degree.

At the end of mashing 6kg of grain, there was about 7L of free flowing wort recirculating in my system that is at very high gravity so I drained off 5L into a cube, refilled with 5L of water heated up to mash out temp, recirced for a while, drainied off another 5L and repeat etc.

The idea is that in a recirc system, the wort equalises to a certain gravity level and no more sugar will dissolve into the wort so by replacing some high grav wort with water, the gravity level is lowered and hence allowing more sugar to then dissolve into the wort.

I think my efficiency for the last brew jumped to about 75% from earlier efforts that were at around 60% by this method (though I don't think I recirced/rinsed enough in the earlier brews).

 

[Muscovy_333]

Thanks all, great feedback. my efficiency has dropped from 75 to 65.

KB, Fly sparge is on my list of too do's, I only just rigged up the recirc and have laid down 3 brews to get my head around the new set-up.
I will adopt all schools of thought that you guys have offered one at a time, and hopefully i can get my efficiency back

thanks again.
Musc

 

[MHB]

I have only seen two common causes for such a sudden change
First was poor quality malt, pretty easy to work out if thats the problem.
Second is too short/hot an element, the surface heat is so high that it kills the enzymes as they flow over the element, quite a common design fault in homemade recirculation systems.
Mark

 

[Online Brewing Supplies]

I have only seen two common causes for such a sudden change
First was poor quality malt, pretty easy to work out if thats the problem.
Second is too short/hot an element, the surface heat is so high that it kills the enzymes as they flow over the element, quite a common design fault in homemade recirculation systems.
Mark

pretty easy also to check the second point you make with a starch test (iodine).
Nev

 

[Muscovy_333]

I have only seen two common causes for such a sudden change
First was poor quality malt, pretty easy to work out if that's the problem.
Second is too short/hot an element, the surface heat is so high that it kills the enzymes as they flow over the element, quite a common design fault in homemade recirculation systems.
Mark

I think the recirculation is ok mark. I have been monitoring the water temp in the heat exchange and it only runs a degree or so above my mash temp as im stepping up.
I actually use my sparge tank with the HEX. It has been working great as all i do is work through my heat steps, the final ramp is only a small one to mash out.

I have been increasing my use of Vienna and Munich 1 in the last few brews so I'm guessing that will impact just wasnt expecting 10% drop.

I am recirculating back into the mash via a 10mm hose. My grain bed is just under the surface level of my recirculating wort which i thought would ensure an even extraction.

How do you guys ensure your recirc passes evenly through your grain bed? Braided hose?

 

[kelbygreen]

it should pass threw evenly, As you will have the liquid ontop of the bed then the bed underneath so the wort that falls ontop will mix with the wort in there so it shouldnt be a big deal and even with fly sparging the water is less dense so it should sit ontop of the wort to some extent. If you get channelling then you will not get even distribution threw the grain and this could be your problem among others, I say do another batch slit the eff half way and see which way you come up. I had one brew lately that was under what I normally get and the next was fine and nothing really changed.

 

[Muscovy_333]

it should pass threw evenly, As you will have the liquid ontop of the bed then the bed underneath so the wort that falls ontop will mix with the wort in there so it shouldnt be a big deal and even with fly sparging the water is less dense so it should sit ontop of the wort to some extent. If you get channelling then you will not get even distribution threw the grain and this could be your problem among others, I say do another batch slit the eff half way and see which way you come up. I had one brew lately that was under what I normally get and the next was fine and nothing really changed.

Sweet.
I was just reading up on some fly sparge ideas for my eski. Should be relatively easy to install something to overcome the possibility of channelling.

Thanks KG