Low og using Brewmonk.

[Jamesman]

Hi everyone, I brewed the bosses boss allgrain kit from darkrock yesterday and my og was 1064 instead of 1072 This is about the 3rd brew on the run using the Brewmonk that the og is too low. I noticed yesterday aswell that filled to the max it was struggling to boil. In the end I had to take 4 litres out to get the boil going. Anyone else had this problem? I thought maybe the boil not working properly had something to do with low og plus the mash temp must've been too low aswell. Long story short I've recalibrated the temp on the Brewmonk and the boil seems to work again. I'm still not convinced it's showing the right temp though after measuring with a hand held thermometer. I've read on a few threads people have had problems with efficiency using the Brewmonk and some people have even taken the top filter out and the middle tube aswell or used grain bags instead to improve efficiency. Could this just be temperature thing or should I start making adjustments to the Brewmonk? Any help appreciated. Cheers.

 

[Scrattajack]

Was the post-boil volume as expected?

 

[foxy]

Hi everyone, I brewed the bosses boss allgrain kit from darkrock yesterday and my og was 1064 instead of 1072 This is about the 3rd brew on the run using the Brewmonk that the og is too low. I noticed yesterday aswell that filled to the max it was struggling to boil. In the end I had to take 4 litres out to get the boil going. Anyone else had this problem? I thought maybe the boil not working properly had something to do with low og plus the mash temp must've been too low aswell. Long story short I've recalibrated the temp on the Brewmonk and the boil seems to work again. I'm still not convinced it's showing the right temp though after measuring with a hand held thermometer. I've read on a few threads people have had problems with efficiency using the Brewmonk and some people have even taken the top filter out and the middle tube aswell or used grain bags instead to improve efficiency. Could this just be temperature thing or should I start making adjustments to the Brewmonk? Any help appreciated. Cheers.

First thing to do when setting up the Brew Monk is check the temperature calibration between the screen and the sensor, there can be a 5 degree discrepancy + or - set it to 67, 68 mash temps I have a Hop Cat which, no matter what I do shows 90 C as the boil and I just have to set my boil time in that 10 mins longer.
Make sure the screen is reading the same as a reliable thermometer held near the sensor. If it isn't, re calibrate the Brew Monk.

Then you have to let the readers know what you have set your efficiency to if you are using Brewers Friend or which ever program you are using, and exactly what your process is. Maybe your expectations are too high, the more fluid the mash the lower the efficiency.

 

[Pennine]

I would recommend taking of the top screen and slow the pump flow so it all circulates through the grain bed and I'd stir it up throughout the first 45 min of a 60 min mash.

Another question is did your grain crush size change? That always affected my efficiency.

As for boiling I always used a immersion boiler to speed up the boil time. It only takes about 10 min with both heaters to get a good boil going.

 

[CaptAwol]

When I do a boil it's 75min as I think it takes about 15 min to get it properly rolling, also as mentioned by Scrattajack was the post volume as expected, taking SG readings and volumes pre and post boil will help identify if it is a boil problem.

 

[Jamesman]

Hi everyone, sorry for the late reply. Scrattajack, I'm not sure what the post boil volume was supposed to be because I just used the instructions I got given and it doesn't say on there. (see attachment).
Foxy, I have recalibrated the Brewmonk now using another thermometer to compare. When I use brewfather the efficiency is set to 71.9. The first couple of brews I hit the target og. It's just the last couple that have been off, making me think it's a temperature problem. I'll find out next brew I suppose.
Penine, I will take the screen out next time and give it a stir every now and then. The grain crush looked OK to me. It was a kit so all the different
grains were mixed in one bag.
Captawol, if I do a longer boil how does it affect the beer?.
Cheers and thanks for all the help

 

[Sandimas]

The grain crush looked OK to me.

I changed grain suppliers recently, both crushed grain, and my efficiency went up 5%. Have you always used the same-brand kits? Maybe this kit manufacturer had a slightly poorer grain crush, like my old grain supplier.

The OG on a kit will only ever at best be an approximation, because it's not sized for your kit or your brewing method. We all get different efficiencies, so the only way to achieve reliability is to work out your efficiency over a few brews and then plug the figures into some brewing software to make your own recipe. Most kits are sized for 75% efficiency, if you get anything less with your equipment then your OG will be less e.g. I get 73% pretty much every time, so if I brew this kit I won't hit the OG either (unless I add some additional grains to make up the difference).

 

[The Baron]

Wise words from Sandimas you need to know your kit and average Efficiency as that is a figure you plug into your recipe builder to work out your grain bill etc

 

[Jamesman]

I changed grain suppliers recently, both crushed grain, and my efficiency went up 5%. Have you always used the same-brand kits? Maybe this kit manufacturer had a slightly poorer grain crush, like my old grain supplier.

The OG on a kit will only ever at best be an approximation, because it's not sized for your kit or your brewing method. We all get different efficiencies, so the only way to achieve reliability is to work out your efficiency over a few brews and then plug the figures into some brewing software to make your own recipe. Most kits are sized for 75% efficiency, if you get anything less with your equipment then your OG will be less e.g. I get 73% pretty much every time, so if I brew this kit I won't hit the OG either (unless I add some additional grains to make up the difference).

Thanks Sandimas, I use a few different companies depending on the grain I need cause sometimes they don't always have the stock in. This is the first time I've used a kit so I've nothing to compare it to. I was thinking though this is a kit I've had lying there for a bit so maybe that's one of the reasons the efficiency is lower. Cheers.

 

[Jamesman]

Wise words from Sandimas you need to know your kit and average Efficiency as that is a figure you plug into your recipe builder to work out your grain bill etc

Thanks Baron.

 

[Jamesman]

Wierd thing with this brew is its still bubbling away and it's been nearly 2 weeks now. Normally it bubbles for a couple of days then calms down a bit. Anyone else had a brew bubbling for so long? I'm supposed to add more hops just before end of fermentation but it's showing no signs of slowing down. Cheers.

 

[Sandimas]

Anyone else had a brew bubbling for so long?

All depends on the type of yeast, I've had them stop bubbling in 3 days and still bubbling at 21. Some are more vigorous than others at the start, some have a long tail-off at the end. In my experience, MJ yeasts seem to take the longest.

What yeast is it?

 

[foxy]

Hi everyone, sorry for the late reply. Scrattajack, I'm not sure what the post boil volume was supposed to be because I just used the instructions I got given and it doesn't say on there. (see attachment).
Foxy, I have recalibrated the Brewmonk now using another thermometer to compare. When I use brewfather the efficiency is set to 71.9. The first couple of brews I hit the target og. It's just the last couple that have been off, making me think it's a temperature problem. I'll find out next brew I suppose.
Penine, I will take the screen out next time and give it a stir every now and then. The grain crush looked OK to me. It was a kit so all the different
grains were mixed in one bag.
Captawol, if I do a longer boil how does it affect the beer?.
Cheers and thanks for all the help

The higher the ABV the lower the efficiency, if your last couple have been in the same ABV range then that is where your problem is.

 

[Jamesman]

All depends on the type of yeast, I've had them stop bubbling in 3 days and still bubbling at 21. Some are more vigorous than others at the start, some have a long tail-off at the end. In my experience, MJ yeasts seem to take the longest.

What yeast is it?

Safale US-05

 

[Jamesman]

The higher the ABV the lower the efficiency, if your last couple have been in the same ABV range then that is where your problem is.

Hi Foxy, the last couple were Bells two hearted abv 6.2% and the other was a stout that was only abv 4.9%. I didn't know it was harder to reach the efficiency the higher the ABV. Cheers.