Alcohol content / reading

[KristianL1]

Hi guys, any thoughts/knowledge appreciated. I'm a long time brewer but never get overly technical or serious - I just like making and drinking interesting beer

But I've just got back into it after a few years and having trouble getting the alcohol content up. I live in a remote area overseas and I can't get the Coopers brew enhancers, I can only get LDM. 

I put down a couple of Pale Ales and Real Ales with just 500g of LDM and turned seemed to turn out a mid strength. Tasted great though. OG/FG gravity readings were about 1.038 / 1.014 - about 3.15% (I think).

I've just fermented a Morgans Frontier IPA with 1kg of LDM + 500g of dextrose I had lying around. 

OG/FG was 1.042 / 1.012 which should be about 3.94% (I think).

I expected it to be higher given I added three times more sugar as the previous 3.15% batches. 

Please enlighten me  Thank you!

[KristianL1]

Note:

I have two hydrometers - the original 10 year old white and read plastic one from the Coopers kit, and a few years ago bought a fancy glass one. 

I just tried to do the FG reading with the plastic one and it ended up about 1.006. 

So I'm guessing there is a chance the glass one or plastic one is bung. Will take OG and FG with both next time - maybe the OG reading with the plastic one will be higher and thus give me a better alcohol reading. 

[Journeyman]

2 minutes ago, KristianL1 said:

I just tried to do the FG reading with the plastic one and it ended up about 1.006. 

 So I'm guessing there is a chance the glass one or plastic one is bung

Did you take the FG with both? 

You can check them by using 20° water - it should read 0.998C at that temp.

[Lab Cat]

30 minutes ago, KristianL1 said:

OG/FG was 1.042 / 1.012 which should be about 3.94% (I think).

I brew with LDM most of the time, it won't ferment out as much as Dex, so your FG will be a bit higher and ABVs will be a bit lower. Only using 500g or any fermentable will always produce a mid strength beer.

A kit and kilo of LDM will be around the 4.2% mark (after you add 0.5% for the bottling sugar.) If you want 5% then add another 500, or Dex - if you you just want ABV and not extra body. Dex will ferment out more than LDM, and go a bit higher for ABV.

Edited July 2, 2020 by Lab Cat

[MitchellScott]

I would be testing your glass hydrometer in some water that is about 20C. It should read give or take 1.000. It may be a tiny bit more or less, you can add/remove this from your readings of beer.

What were the volumes of the IPA brew? From what you have said, the reading should have been higher. If you give me the volumes I can run it through a calculator and give you a pretty accurate idea of what OG/FG and ABV you will have.

You also may not have mixzed the ingredients fully before taking a reading. This can especially happen with dry malt or sugars (dex etc). The good thing about extract brewing is you can easily calculate how much sugar is in your brews and therefore the final ABV outcome.

Mitch.

[KristianL1]

19 minutes ago, Journeyman said:

Did you take the FG with both? 

Yes - 1.012 with the glass and 1.006 with the plastic. I didn't take the OG with the plastic but will do it with both next time.

 

19 minutes ago, Journeyman said:

You can check them by using 20° water - it should read 0.998C at that temp.

I didn't know this - I will check that next time. Temp should have been about 20C

[KristianL1]

2 minutes ago, Lab Cat said:

A kit and kilo of LDM will be around the 4.2% mark (after you add 0.5% for the bottling sugar.) If you want 5% then add another 500, or Dex - if you you just want ABV and not extra body. Dex will ferment out more and go a bit higher.

Thanks Lab Cat - this is what I figured - 1kg of LDM should be about 4.2%. Add 500g of Dex and should push up towards 5%.

Which is what I did on this batch - 1kg LDM  + 500g dex. But on the hyrdrometre readings I'm getting still seems to be 4% or maybe lower which is what's confusing me... maybe it is up towards 5% but the hyrdrometers (or temps) are crook. 

[KristianL1]

5 minutes ago, MitchellScott said:

I would be testing your glass hydrometer in some water that is about 20C. It should read give or take 1.000. It may be a tiny bit more or less, you can add/remove this from your readings of beer.

What were the volumes of the IPA brew? From what you have said, the reading should have been higher. If you give me the volumes I can run it through a calculator and give you a pretty accurate idea of what OG/FG and ABV you will have.

Thanks Mitch - I'll test both hydrometers at 20C. 

The IPA is a 23L batch. Is that the volume you mean?

 

5 minutes ago, MitchellScott said:

You also may not have mixzed the ingredients fully before taking a reading. This can especially happen with dry malt or sugars (dex etc). The good thing about extract brewing is you can easily calculate how much sugar is in your brews and therefore the final ABV outcome.

I think they were pretty well mixed but will take extra note to do this next time - the LDM/dex did clump together a bit after adding it to the water so maybe all clumps weren't dissolved.

[MitchellScott]

5 minutes ago, KristianL1 said:

Thanks Mitch - I'll test both hydrometers at 20C. 

The IPA is a 23L batch. Is that the volume you mean?

 

I think they were pretty well mixed but will take extra note to do this next time - the LDM/dex did clump together a bit after adding it to the water so maybe all clumps weren't dissolved.

Your IPA will come out at:
4.8% (kegged)
5.2% (bottled).

A good idea is put 1L of boiling water into the FV then mix all the dry malts/sugars, before adding in the rest of the water + tins. This helps make sure all the dry stuff is dissolved, but sometimes sucks to do in summer due to the (already high) temp of tap water.

Also, it sounds like 1.012 is the FG that is more to be correct. The plastic hydrometers in my experience are pretty shitty, glass tends to be much more accurate. But test them out

Mitch.

Edited July 2, 2020 by MitchellScott

[KristianL1]

28 minutes ago, MitchellScott said:

Your IPA will come out at:
4.8% (kegged)
5.2% (bottled).

A good idea is put 1L of boiling water into the FV then mix all the dry malts/sugars, before adding in the rest of the water + tins. This helps make sure all the dry stuff is dissolved, but sometimes sucks to do in summer due to the (already high) temp of tap water.

Also, it sounds like 1.012 is the FG that is more to be correct. The plastic hydrometers in my experience are pretty shitty, glass tends to be much more accurate. But test them out

Mitch.

Awesome thanks Mitch - if we're up towards 5% I'm happy.