Not meeting Original Gravity

[JimSY]

Good morning all - this is my first, but possibly one of many, posts! Hopefully someone can advise on my problem...

I'm a relative newbie who's brewed a few small (4L) batches with a reasonable amount of success from a drinkability point-of-view (the brews taste like they ought to overall). However, I'm not convinced about their strength as they are meeting the anticipated original gravity and are falling short by some amount. I use 4L of initial liquor and 3L for the sparge and my mash does drop a few degrees owing to the equipment I use (a two-gallon Igloo cooler). Might there be some obvious trick I am missing or is this kind of thing inevitable with a far from perfect set-up? Does anyone have any advice on how I might improve the OG?

Many, many thanks in advance!

Jim

 

[Clint]

I'm only learning myself ....what is your efficiency? You can use the forum calculator for this. Adding a little extra malt can boost efficiency.

 

[Martybhoy]

Can you post an example of a recipe you brewed, the actual gravity and the gravity you expected?

For improving the efficiency of your mash (higher OG), I give mine a stir after 5 and 30 mins.

Also make sure you don't have any dough balls (big clumps of grains) in your mash - stirring whilst adding the grains will help avoid this.

Sent from my MotoG3 using Tapatalk

 

[Sandimas]

The big variable in AG brewing is mash efficiency: it'll take you a few brews to work out what that is, but chances are it isn't the same as the recipe you're using.

e.g. my brewing software comes with a default 70% efficiency, when I started AG brewing I too was missing my target OG, and eventually worked out that I was getting at best 68% mash efficiency, so I need to use more grain than in the recipe to hit my target OG.

If you made a note of your brew volume, the amount of grain, and your actual OG you can work out your efficiency by plugging it into brewing software. If you can't do this, post it on here and I or someone else will work it out.

 

[Gunge]

I've noticed a pretty substantial rise in efficiency for the last few brews, to the point where I'm going to have to adjust downwards the amount of grain used to retain the same wort volume without an outrageously high OG. How? One recent brewday I felt uncharacteristically laid-back and had time on my hands. As a result the sparge was carried out meticulously and at a glacial rate. I did it again for subsequent brews and got the same results. So there you have it but by the christ it's boring.

 

[dad_of_jon]

Good morning all - this is my first, but possibly one of many, posts! Hopefully someone can advise on my problem...

I'm a relative newbie who's brewed a few small (4L) batches with a reasonable amount of success from a drinkability point-of-view (the brews taste like they ought to overall). However, I'm not convinced about their strength as they are meeting the anticipated original gravity and are falling short by some amount. I use 4L of initial liquor and 3L for the sparge and my mash does drop a few degrees owing to the equipment I use (a two-gallon Igloo cooler). Might there be some obvious trick I am missing or is this kind of thing inevitable with a far from perfect set-up? Does anyone have any advice on how I might improve the OG?

Many, many thanks in advance!

Jim

You could run the boil for a bit longer although the beer will be a darker shade. If you added 15 mins on then put the hops in 15 mins later than planned to stop it getting extra bitter. :-) Or recycle the runnings from the mash a few times.

 

[Clint]

I had around a 7 % rise in my last brew ...I too sparged at a leisurely rate but mashed for 2 hours as something cropped up...I stirred the mash half way through the first hour too.

 

[Martybhoy]

Using the freshest possible grain will help efficiency too. Im assuming you're buying crushed grains. If so, don't order loads in advance as lying too long will reduce sugars available in the grains.

Sent from my MotoG3 using Tapatalk

 

[JapanBrew]

All the advice is great but many brewers forget that there are 3 kinds of sugars that can be produced. 2 of which we use in beer and 1 that the yeast will go to first. These sugars are created during mash by 2 enzymes that are the power lifters of what we think is our doing. If you're Fg is too high than expected than your mash was setup for alpha amylase. These enzymes will create complicated, random chain of sugars. The yeast will work on those sugar strains but not efficient. You'll have to pitch double the yeast and keep the fermentation temp at the high end. But at that temp, the yeast poop, after products, will be somewhat interesting. These enzymes work at 66 degrees and up. 66 is truly when they start to wake up. 68 and up is where they work well.
Now let's go to beta amylase. These guys are the work horse. They start at 62 or so. These will produce short chain, maltose sugars that yeast just LOVE! If you mash at only this temp you'll get a dry beer. I've had some drop below 1.000 before. That is the extreme. So mashing temps for a medium body beer should stay at 67 to 68. Now here's the problem. If you keep your mash at 70 or above, beta amylase will die. So as your mash temp drops, you'll have a hard time getting those really fermentable sugars you need to get your FG down. I've seen beta amylase stay working within 10 minutes of high temps. After that, they die. So it's better to try and hit a little lower then, over the course of the mash, adding a liter of boiling water to the mix to raise or maintain the temp.

 

[foxy]

Wrap your esky in a couple of blankets and try an overnight mash, if you are only falling a few points short overnight mash will nail it.

 

[Litmus]

I would be interested to understand how you are calculating the OG? Are you using some software to calculate?

 

[JimSY]

Hi all,

Apologies for the late reply - I've been away for the week - and thank you all very much for the varied advice. Most of what has been posted makes perfect sense and will try to implement your suggestions in my next brew.

My most recent effort was a Northern Brown Ale (from Greg Hughes's book Home Brew Beer) scaled down for a four litre batch. Target OG was 1.052 but I only managed 1.039. According to the efficiency calculator I'm working at 56% which, I suppose, explains why the target wasn't met.

As I said, previous efforts have been drinkable (a recent oatmeal stout was most tasty!) but clearly won't have the kick that they should have.

Ah well, onwards and upwards - thanks again for the advice, folks!

Ta - Jim

 

[Duxuk]

I agree with Foxy that an overnight mash will help your OG. I reckon I get about 10% improvement in efficiency. Do you measure your OG at 20C? You wouldn't be the first to get a low OG because you're testing it whilst it's hot. Yes, I did that!
The other thing about efficiency is that you must not lose any wort. It's easy to waste some in dead spaces.

 

[Sandimas]

With the small volume you are brewing you should easily be able to up that efficiency.

I do 10-12L BIAB and here's what I do. I get a consistent 68% efficiency.

- Mash in a bag in a 12L stockpot.
- Strike temp 73C which usually drops to the target 66/68 upon adding the grain.
- Give it a really good stir.
- Add a little hot / cold water if the temp needs adjusting.
- Put your oven on the lowest setting, get it up to temp then turn off.
- Put the stock pot in the oven to keep up the temp during the 60min mash.
- Given it another good stir at the mid-point, and at the end.
- Dunk sparge in another stockpot or spare FV.

 

[chub1]

With the small volume you are brewing you should easily be able to up that efficiency.

I do 10-12L BIAB and here's what I do. I get a consistent 68% efficiency.

- Mash in a bag in a 12L stockpot.
- Strike temp 73C which usually drops to the target 66/68 upon adding the grain.
- Give it a really good stir.
- Add a little hot / cold water if the temp needs adjusting.
- Put your oven on the lowest setting, get it up to temp then turn off.
- Put the stock pot in the oven to keep up the temp during the 60min mash.
- Given it another good stir at the mid-point, and at the end.
- Dunk sparge in another stockpot or spare FV.

:thumb:
Dunk sparging,for me has really improved my brews:)