Woeful Extraction Or Dodgey Hydrometer?

[Hugo]

Seeking some advice...

Relatively new to partials, but I have produced some reasonable efforts. However....

I used a combination of Promash and the Mildura Brewery website to attempt a Mallee Bull clone (a fine strong ale), however after the mash and boil, the SG reading was very low (in the 1030's) despite 1.5kg LME and 2.3 kg grain (pale/crystal/caraf special) in the grist. Promash expected sg at 75% efficiency was 1051. Proceeded to bottling at about SG 1010, and predictably the beer tastes quite watery and has the feeling of a "light" beer. Definitely not the intention.

Repeat effort last night on a LCPA clone that I had boosted the grist to assume 65% efficiency. Again a woeful SG in the 1030's. This time I took drastic measures and added another tin of LME. SG read 1050 when the yeast was pitched.

I suspect the issue may lie in my sparging technique - I just drain the mash through a big conical pasta colander and trickle 77 degree water (equivalent to volume in the mash) over the grains from a jug. It usually only takes a few minutes. Haven't recirculated the wort. I also avoided immersing the grain bed with sparge water for fear of mobilising too many tanins (may be unfounded). Is this where the likely problem lies? Should I just return the grains from the mash into a container and cover with the sparge water and then drain again through the colander?

Only other explaniation would be a dodgey hydrometer, but it seems to read the bottom end OK after fermentation?

All advice/comments appreciated.

cheer.

 

[warrenlw63]

Only other explaniation would be a dodgey hydrometer, but it seems to read the bottom end OK after fermentation?

All advice/comments appreciated.

cheer.

Check your hydrometer in 20 degree water. If it reads zero there's not a problem.

Warren -

 

[BOG]

I made this mistake last month.
After about 60 responses to my thread someone asked if the wort was cool when I tested the SG. The answer was no.

Make sure you are sampling at 20C or if not measure temp and adjust for the SG using the calcualtions in the software.


BOG

 

[Hugo]

I made this mistake last month.
After about 60 responses to my thread someone asked if the wort was cool when I tested the SG. The answer was no.

Make sure you are sampling at 20C or if not measure temp and adjust for the SG using the calcualtions in the software.
BOG

It's a good point.. but the wort would have been no warmer than 30 degrees. Correction on promash is very minor. (ie 1030 to 1033). Not really enough to explain the disparity?

 

[jonw]

I suspect the issue may lie in my sparging technique - I just drain the mash through a big conical pasta colander and trickle 77 degree water (equivalent to volume in the mash) over the grains from a jug. It usually only takes a few minutes.

I used the same technique for my first few partials, and basically got the same result.

Once you've drained the wort through the colander, return the grain to the mash tun and add your sparge water. Stir well, leave for ten minutes, and then drain.

I found that approach improved my efficiency significantly (in fact, so much that I'm not sure I believe my hydrometer!)

Cheers,

Jon

 

[Steve]

Is the thermometer you use for the mash and sparge water correct?

 

[Adamt]

Make sure you adequately mix in the LME, it's prone to clumping/sinking. Or, get a refractometer B), they're awesome and you only waste a few drops of precious wort.

 

[NickB]

Hi,

aslo make sure your volumes are set correctly in your software. I was having this same issue on my previous AG batches, and thought I was having problems with efficiency (50%-65%).

Turns out I was about 4 or 5 L wrong on my volumes, and was actually getting 80%-90%....I'm a happy camper now!

As stated above too, make sure you're LME is mixed well.

Cheers

 

[reVoxAHB]

Check your hydrometer in 20 degree water. If it reads zero there's not a problem.

Warren -

And to be on the safe side, double-check the hydrometer itself for calibration temperature. Mine calibrates at 60F/15.5C, for example, and is clearly displayed on the side.

In regard to your technique, you didn't mention whether you are boiling or not, so I would suggest boiling both your run-off and LME for at least 60 minutes. Consider fly-sparging next time around. And don't worry about tannin extraction. It generally only occurs after the ph rises above 6.0 (generally occurring after a lengthy sparge 90+ minutes). ph strips, etc. will assist in this as desired, and sparge water can be lowered using acidification, etc.

There's plenty of threads about regarding batch/fly sparging. Whichever you go with, a recirc until the run-off clears is desireable.. No need to build a grant.. a little jug is fine.. say 3-6L, or 4-5 mins of slow run-off would do you.

reVox

 

[Wardhog]

I used the same technique for my first few partials, and basically got the same result.

Once you've drained the wort through the colander, return the grain to the mash tun and add your sparge water. Stir well, leave for ten minutes, and then drain.

I found that approach improved my efficiency significantly (in fact, so much that I'm not sure I believe my hydrometer!)

Cheers,

Jon

I found exactly the same thing. I say this expecting to be shouted down, but I think you're not going to sparge anywhere near effectively unless the grain is sitting in water. Just sprinkling water over them from above is not going to do it.

Plonk the grain back in, and fill with your sparge water then give it a good stir.