Lower OG Partial Mash

[acreid]

Hi there, just looking for some advice on how my second partial mash brew ended up with a much lower OG than expected. I got 1044 instead of 1062. I followed a punk ipa recipe for my first partial mash and it all went to plan, however I made this recipe myself.

2500g Pale Malt
250g Caramalt
500g Flaked oats
500g Flaked Wheat
1000g DME - added in the fermenter.

I mashed in 10L for 60 minutes and boiled for 60 minutes. Mash was at 65 degrees.

Any advice on where I went wrong would be appreciated!

 

[Clint]

What's your batch size?

 

[acreid]

What's your batch size?

19.5 litres

 

[MyQul]

What's your batch size?

Brewmate tells me 19L

Edit. oo only 0.5L out

 

[MyQul]

Are you sure you got 1.044 as thats only about 40% efficiency. Did you mix the DME properly?

 

[Clint]

Punching the numbers gives 1059...perhaps the dry malt wasn't fully dissolved.

 

[MyQul]

Punching the numbers gives 1059...perhaps the dry malt wasn't fully dissolved.

I think that depends on what efficiency you've got your software on. Brewmate gives me 1.060 at 70%

 

[acreid]

Are you sure you got 1.044 as thats only about 40% efficiency. Did you mix the DME properly?

Poured the DME slowly into the wort inside the fermenter and gave it a right good stir so I doubt it can be that. Did I do the mash correctly at 65 degrees for 60 minutes?

 

[MyQul]

Poured the DME slowly into the wort inside the fermenter and gave it a right good stir so I doubt it can be that. Did I do the mash correctly at 65 degrees for 60 minutes?

Yes you did the mash correctly. Did you stir the mash at any point (as this helps efficiency). Did you sparge? If you didnt this might be the reason

 

[acreid]

Yes you did the mash correctly. Did you stir the mash at any point (as this helps efficiency). Did you sparge? If you didnt this might be the reason

I stirred the grain at the start so it was all soaked. Pre heated the oven to 70 then put the pot in for an hour. I poured a kettle of water at 70 degrees over the grain after the mash if you could call that sparging and squeezed the bag.

 

[MyQul]

I stirred the grain at the start so it was all soaked. Pre heated the oven to 70 then put the pot in for an hour. I poured a kettle of water at 70 degrees over the grain after the mash if you could call that sparging and squeezed the bag.

Ideally you need to stir the mash every 20 mins or so to get the best out of the grain but I dont think not stirring during the mash would account for such a low OG.

Yes that's a sparge. Tbh, it's a bit of a mystery. I cant think of anything else as to why you'd get such a low OG

 

[acreid]

Ideally you need to stir the mash every 20 mins or so to get the best out of the grain but I dont think not stirring during the mash would account for such a low OG.

Yes that's a sparge. Tbh, it's a bit of a mystery. I cant think of anything else as to why you'd get such a low OG

Cheers for the quick reply anyway and Clint!
I’ll stir it more next time and maybe reduce the grain slightly as almost 4kg was quite a lot for a stove top I’m guessing.

 

[MyQul]

Cheers for the quick reply anyway and Clint!
I’ll stir it more next time and maybe reduce the grain slightly as almost 4kg was quite a lot for a stove top I’m guessing.

Thats something I didnt think of, was your mash particularly thick because that can effect how much extraction from the grain you get

Sorry we could help more but if your ever need help to make a key lime pie @Clint will have you covered

 

[acreid]

Thats something I didnt think of, was your mash particularly thick because that can effect how much extraction from the grain you get

Sorry we could help more but if your ever need help to make a key lime pie @Clint will have you covered

Less grain and more DME next time then! Iv got 1kg of Young’s brewing sugar somewhere so I could always add that if I want to up the OG I suppose.

 

[MyQul]

You could add the sugar.Just remember it'll thin out the body of the beer (not necessarily a bad thing but that's what will happen)

 

[acreid]

Thanks again for the advice!

 

[Clint]

When using DME I found it likes to clump up so sometimes can be difficult to stir in ..it won't matter if it has the yeast will get it.

 

[terrym]

I did the calculation in BF using your total grain bill and the predicted OG came out at 1.057. If the DME was then reduced to 300g the OG dropped to 1.044. I suppose its possible that 700g of DME could have clumped together.
I also do partial mashes and also add 1kg DME to the FV but either make sure its dissolved first in a pan slowly brought to the boil or dissolve it directly in the FV with near boiling water at the start, so I know its all dissolved, although that can be difficult. And then I add the wort from the grain mash and boil. And my OGs are always as predicted or maybe one point down.
Anyway I wouldn't have thought your mash was so far off that it affected the OG by the margin you have told us. So I would have thought it was undissolved DME, or a spurious SG reading. You havent said how you took the reading hydrometer (could be worth checking calibration ) or refractometer (???). But if it does turn out to be an error by either of those dumping in lots of brewing sugar may spoil your beer. So go carefully

 

[acreid]

I did the calculation in BF using your total grain bill and the predicted OG came out at 1.057. If the DME was then reduced to 300g the OG dropped to 1.044. I suppose its possible that 700g of DME could have clumped together.
I also do partial mashes and also add 1kg DME to the FV but either make sure its dissolved first in a pan slowly brought to the boil or dissolve it directly in the FV with near boiling water at the start, so I know its all dissolved, although that can be difficult. And then I add the wort from the grain mash and boil. And my OGs are always as predicted or maybe one point down.
Anyway I wouldn't have thought your mash was so far off that it affected the OG by the margin you have told us. So I would have thought it was undissolved DME, or a spurious SG reading. You havent said how you took the reading hydrometer (could be worth checking calibration ) or refractometer (???). But if it does turn out to be an error by either of those dumping in lots of brewing sugar may spoil your beer. So go carefully

OG reading was taken at 21 degrees using a hydrometer and I double checked by putting it in water. I’m sure it was down to too much grain because it was syrup like in the grain bag when I squeezed it.
I have left it as it is regarding the extra sugar. Thanks for the reply!

 

[MyQul]

I’m sure it was down to too much grain because it was syrup like in the grain bag when I squeezed it.

I'd say, there's your cause. It should be watery when you squeeze the grain bag. The mash liquor/sparge liquor can only hold so much sugars. So not enough water in the mash means you wont be washing out the max sugars your able to