Low OG. What's wrong?

[Greg B]

Hello All

I've just kicked off my 2nd brew and have a rather low OG. It's a puzzling me.

So, for my first ever effort I used a Coopers kit (Canadian Blonde), 1kg of extra light DME and the kit yeast. I screwed up and mixed everything in 2 litres of cold water, some of the DME clumped and my OG was 1031. Explainable by the fact not everything mixed in well. FG was 1008. It tasted great all the same.

2nd brew. I've kept it simple again, this time using a Coopers Mexican Cerveza kit, with 1kg of extra light DME and kit yeast. This time I used 2 litres of almost boiling water. Mixed everything in well, then topped up to 23 litres. OG was 1027!!

The kit instructions suggest it should be 1038.

I tested the hydrometer with water and it register 1001. So nothing too wrong there.

Any idea why my OG is so low to begin with. By my calculations these brews should be coming out at about 3-3.5% but after 3 pints I'd suggest they're a little stronger, but that could just be me.

I'd be interested in your thoughts.

Cheers

 

[Greg B]

OK, so some people use sugar and DME. Should I be doing this?

My brother's brewed exactly the same kit with 1kg of light DME (rather than extra light) and he's got an OG of 1038. That's quite a difference, and also nearer what Coopers beliew the OG should be.

 

[Neil1987]

You sure you gave it a good thrashing and no clumps at bottom?

 

[Banbeer]

Did you add any sugar/dme to the second brew? This is a one can kit you're using and the one before I pressume? It's only the 2 can kits that don't need any sugars adding as the second can is the fermentable bit of the kit.

 

[honeymonster]

Mixed everything in well, then topped up to 23 litres. OG was 1027!!

Did you mix after topping up? If you just put the water in and took the reading it might still be concentrated at the bottom.

The strength of final beer will be normal because all the sugar/fermentables will be eaten but you'll get false low hydrometer readings if you take it from the top.

 

[terrym]

OK, so some people use sugar and DME. Should I be doing this?

My brother's brewed exactly the same kit with 1kg of light DME (rather than extra light) and he's got an OG of 1038. That's quite a difference, and also nearer what Coopers beliew the OG should be.

You are doing nothing wrong.
When you make up a kit using kit can and extra sugars you can only end up with one OG for any quantity of combined sugars in any one volume of wort. It can't be anything else. And it can be calculated using this.
https://www.brewersfriend.com/homebrew/recipe/calculatorSo if two people made the same kit to the same volume with identical quantities of sugars the OGs should be the same. However if the sugars are not properly mixed you probably get a lower reading if top sampling and possibly higher readings if sampling through a tap. It sounds to me that you are not mixing your wort properly. I made up a kit today and my measured OG was within one point (0.001) of the predicted OG because I made sure everything was properly mixed especially the LME that can stick to the bottom of the FV. However although the OG would be the same for our two kit brewers their FGs could be different for all sorts of reasons.

 

[Greg B]

You sure you gave it a good thrashing and no clumps at bottom?

Thrashed the living daylights out of it. It was smooth and quite thick by the end before I topped up.

 

[Neil1987]

Did u add sugar ?

 

[honeymonster]

Thrashed the living daylights out of it. It was smooth and quite thick by the end before I topped up.

So you didn't mix after topping up?

 

[Greg B]

I didn't add sugar as such. I used the single can from the kit, plus 1kg of extra light DME (instead of the kit recommended Brew Enhancer from the kit supplier, as per recommendations on here).

I mixed the wort very thoroughly. I topped up with water from a hose and whilst the splash from the hose mixed things up a little, I didn't mix the whole thing again with my spoon afterwards. So maybe top sampling is the reason here. Its a good point.

 

[honeymonster]

That'll be it mate, especially if it was really thick before you topped it up!

 

[Neil1987]

Yeah it was all stuck at the bottom next time keep thrashing as you add water

 

[Greg B]

OK guys, that's for the pointers. But as you say, it shouldn't matter too much in the end in terms of ABV?

 

[Greg B]

Or should I give it a quick mix now? Its been going for 24 hours

 

[honeymonster]

Or should I give it a quick mix now? Its been going for 24 hours

Nah, it'll be fine. The yeast will still do it's job. And it won't affect strength, the all the good stuff in still in there!

 

[Greg B]

Brill. Thanks all for your help guys. Onwards and upwards!

 

[terrym]

If its any help I have just acquired a mixing paddle, like a long spoon but flat and with holes in the paddle section and its much more effective for mixing the wort.

 

[Greg B]

If its any help I have just acquired a mixing paddle, like a long spoon but flat and with holes in the paddle section and its much more effective for mixing the wort.

Yeah, I've got one of those. It worked great when mixing the wort. I just need to remember to use it when mixing in the top up ☺

 

[dwhite60]

I put a Coopers Real Ale kit together yesterday. Per recommendations I .....

Added LDME and sugar to 4 liters of water in a kettle. I dislike dry malt extract. It gets on everything.
Heated slowly to ~72C stirring constantly until everything dissolved.
Removed from heat and added can contents and stirred until well blended.
Poured into bucket.
Added water a few liters at a time and stirred between additions so I got a good homogeneous mix.
Sample off the top measured 1.046, right where it should have been.

I burned liquid extract on the bottom of the kettle of my first brew over thirty years ago. It's a painful memory.

 

[Edison]

You sure you gave it a good thrashing and no clumps at bottom?