1 Posted: Monday, October 09, 2017 2:53 PM

So I'm a complete newb. Made my first batch using the 1.3kg can supplied with the 15L craft brew kit, now bottled and waiting a couple of weeks before trying. I took the manufacturer's word for the OG at 1047 and tested after about 6 days and got 1016. Days 8 and 9 were 1005 so I bottled. Soon after I was passing by the brew shop and was convinced by the proprietor I could use half a 1.7 can without any added sugar/dextrose because it was designed for 23 litres and I would only be filling to 8.5 litres. Mixed up half the can with some hot water and then some cold water and tested the OG. It was only 1026. Using a % alcohol calculator that means an alcohol level of 2.75% - a bit low.

After a bit of faffing around I added some sugar and molasses (it is an ‘Old’ type beer can) and tested again. It was about 1034 but at that stage I thought I'd just cut my losses and put the FV away. At his point I looked on the internet I saw that: a. different temperatures can give different SG results b. you need to calibrate the hydrometer because it might not be accurate.

Sure enough I tested just water and it had a SG of about 996. I tried a few different temperatures and it didn't seem to make any difference. Not completely sure but the temp of the brew may have been around 28 degrees when I tested.

The hydrometer was just the one supplied with the kit so maybe it is cheap and nasty.

I also live in a city that is about 577 metres (1900 feet) above sea level. I wondered if that makes a difference.

Any suggestions? Use the whole can next time? After all it is supposed to be supplemented with 1kg of dextrose anyway.

2 Posted: Monday, October 09, 2017 3:20 PM

28C will cause the hydrometer to read about 2 points lower than the actual SG, assuming it's calibrated to 20C. Coupled with the .996 in water, the proper OG would have been about 1.032 for that half kit can brew before other additions were made. It's a little low but not unexpected for 850g of liquid extract in 8.5L of water. 850g dry extract in 8.5L water would yield and SG of about 1.037; the same weight of liquid extract will give a lower SG compared to dry as it contains about 20% water.

I would use 1kg dry malt instead of 1kg dextrose, you'll end up with a better beer. Dextrose results in it being quite thin and watery. If you plan to use half a kit in the 8.5/9L or whatever, just chuck in 500g dry malt with it and you should get a pretty full strength beer. Alternatively you could make it to 11L and use the krausen kollar to give the fermenter more headspace. This would get closer to how it'd turn out made with a full kit and kilo in 22/23 litres.



3 Posted: Monday, October 09, 2017 3:45 PM

Thanks Kelsey. I'll see how I go.

No point in adding anything now after two days I guess?

4 Posted: Monday, October 09, 2017 11:09 PM

You could, or just leave it be and chalk it up to a learning experience. Up to you mate.