Alcoholic Ginger Beer (5%) Using Coopers Gb Can... Whack Hydrometer Re

[lukemarsh]

I just brewed up an alcoholic ginger beer using a Coopers Ginger Beer can and 2kg of Dextrose with a final volume of 18L.
The brew was quite warm when I first placed it in the cellar, so figured I'd put some wet towels and ice packs around it with a fan on to cool it down to about 25 degrees before I put the yeast in.
I did a hydrometer reading while it was still fairly warm (about 30 degrees) and it came out at around the 1.053 mark...
Later, once it had cooled to about 26 degrees, I did another test and it read 1.046...

I did not put any yeast in before these readings, the fermenter was sealed with an airlock to keep it clean while I waited for it to cool down.

Why did I get two totally different readings in the space of about an hour or so? Which reading should I go by?

P.S. The first reading I did (the one that read 1.053) was straight out the fermenter tap without having run a bit through first before testing... don't know if that makes alot of difference since it was totally sterilized and hadn't created any sediment cake yet.



The other thing is, I am aiming for an alcohol content of 5% or higher... will this definitely ferment down enough to be that alcoholic? Knowing my luck it will only get down low enough to be about 3% or something and refuse to go any further, creating frustration and confusion... stuff like that tends to happen to me!


Thanks!

 

[chopdog]

how long do you think this will take to ferment. was hoping to have one ready for a party comming up

 

[manticle]

P.S. The first reading I did (the one that read 1.053) was straight out the fermenter tap without having run a bit through first before testing... don't know if that makes alot of difference since it was totally sterilized and hadn't created any sediment cake yet.

And therein lies the difference. Malt and sugars that are not properly mixed through will be the first thing to come out the tap and give a wacky (usually way too high) reading. Yeast cake is not relevant - sugar is.

 

[Nevalicious]

I did one of these recently with a little help from my friends

I used 1 kg of Dex and 500g of malt just to make it a little less "thin", bottled two weeks ago. Couldn't help myself, had one, tastes good already... Anywho, mine ended up smack bang around 5%. 23 lt batch BTW

Yours with 2kg of fully fermentable Dextrose made to only 18lt should have no troubles reaching near 6% i'd say... Maybe someone will work it out for you (beer smith or the like?)

Tyler

 

[bum]

I did a hydrometer reading while it was still fairly warm (about 30 degrees) and it came out at around the 1.053 mark...
Later, once it had cooled to about 26 degrees, I did another test and it read 1.046...
...
Which reading should I go by?

Neither. You should usually be taking your measurements at either 15 deg or 20 deg (depending on temp specified by manufacturer). Your hydrometer should have come with a piece of paper that tells you how to adjust for temp. Give it a squizz and you'll be able to work out what your gravity was at the calibration temp. Base it off the second reading, not the first.

 

[bum]

how long do you think this will take to ferment. was hoping to have one ready for a party comming up

Ginger beers generally take longer than beers to condition. When's the party. I personally wouldn't even bother trying a straight kit GB sooner than 6 weeks from pitch.

 

[lukemarsh]

It has been over 24 hours now and the airlock hasn't started to bubble! How long til I should start panicking?

 

[manticle]

Did you work out your OG properly?

Check the gravity and see if it's dropped. That means it's fermenting. Is there condensation forming on the lid?

Airlock means very little.

 

[Muggus]

Later, once it had cooled to about 26 degrees, I did another test and it read 1.046...

The other thing is, I am aiming for an alcohol content of 5% or higher... will this definitely ferment down enough to be that alcoholic? Knowing my luck it will only get down low enough to be about 3% or something and refuse to go any further, creating frustration and confusion... stuff like that tends to happen to me!

What you should take into account with ginger beers, especially if your additional fermentables are nothing but sugar, is that it will more often than not attenuate down 1.000, if not lower (especially with higher alcohol %).
This will mean that even if your beer did start off at 1.046, it will still turn out to be 5% alcohol.

 

[lukemarsh]

Did you work out your OG properly?

Check the gravity and see if it's dropped. That means it's fermenting. Is there condensation forming on the lid?

Airlock means very little.

If what I explained at the start of the thread was a correct OG reading, then yes if the way I did it was right and there isn't much difference with the temperature change, then it would be 1.046.
I will check the gravity again soon when I have time, but for now all I can see is there is condensation underneath the lid and there is a ring of crud around the top of the liquid.
The airlock is bubbling, but not as rapidly as it has when I've brewed normal beers.

 

[manticle]

Don't worry about the airlock. Crud and condensation means it's fermenting.

 

[lukemarsh]

Alrighty... just did a hydrometer test and it's now 1.041 ish.
Also had a taste (only been in the fermenter for about 5 days) and it actually tastes quite nice already!

The can says fermentation should be finished in around 6 or so days, but that's with only 1 kilo of sugar (approx. 3% alc)... would mine, having double the dextrose, take longer to finish fermenting? I know I need to wait until the readings are the same for 2-3 days, but in general would it take longer because of the higher amount of dex?

 

[bum]

I don't think the dex will account for the difference you're seeing here. After allowing for your temp problems on your hydro sample I'd say you've dropped maybe 3 points in 5 days. What temp are you fermenting at?

 

[lukemarsh]

The fermenter is at a constant 22 - 23 degrees in a completely dark and dry place (underground cellar with brick and raw earth walls), which is perfect for the instructions on the can (says to ferment between 21 and 27 degrees).

Considering I didn't allow the sample to cool down in the first hydrometer reading (was about 26 degrees), what would've the sample read if correct? As in, what should I assume the OG actually was?
And why has the reading not lowered much since the OG? I worked out on the brewcraft website using their alcohol calculator (using OG and predicted FG) that it needs to drop to 1.015 to acquire an alcohol content of 4.9% if my OG is 1.046... so I have a long way to go