OG not right

Australia & New Zealand Homebrewing Forum

Help Support Australia & New Zealand Homebrewing Forum:

Joined
1/5/20
Messages
45
Reaction score
8
Location
Hazelbrook NSW
Hi all

I have been AG brewing now for just over 12 months. I generally buy AG recipe kits from BeerCo and I follow the recipes to a tee. The last 3 brews I have done I have missed the OG and FG of the brews and I am after some pointers about what I could be checking to get a more accurate outcome. As an example a Double IPA recipe I am currently fermenting missed the OG by 16 points (my OG was 1061 the suggested OG on the recipe was 1076). The previous brew, a milk stout, my OG was 1060 (recommended OG 1067) and my FG was 1022 (recommended 1016).I am using a Brewzilla and fermenting under pressure in an allrounder.

Don't get me wrong the beers still taste great, however it seems that I am ending up 2% short on ABV for my last few brews and am keen for some pointers on what I could be doing wrong, or what I could possibly tweak.

One thought is I need to calibrate my Brewzilla (seems to be showing 103 on the display when setting to HH for boil. if it is 3 degrees out that would affect the temperature I am mashing at, but would that make that much of a difference?

I look forward to receiving any and all advice.

Cheers
 

MHB

Well-Known Member
Joined
1/10/05
Messages
6,855
Reaction score
4,317
Location
Newcastle
Sounds like your temperature is the first place to look.
Given that you are starting under target and finishing over target that’s a real clue that you are mashing way too hot. Bit hard to tell how far off (not enough information) but I suspect a bit more than 3oC.

Every brewer should have a reference thermometer, one that you can trust and use regularly to check your sensors and mechanical thermometers. Electronic and Bi-Metalic arent really that trustable. Get yourself a good glass lab thermometer (not a cheap Chinese one).
My local stocks Alla from France for $15, they or something similar would be a good call.

There are some other factors that would be worth taking a look at but I would start with temperature.
Mark
 
Joined
1/5/20
Messages
45
Reaction score
8
Location
Hazelbrook NSW
Sounds like your temperature is the first place to look.
Given that you are starting under target and finishing over target that’s a real clue that you are mashing way too hot. Bit hard to tell how far off (not enough information) but I suspect a bit more than 3oC.

Every brewer should have a reference thermometer, one that you can trust and use regularly to check your sensors and mechanical thermometers. Electronic and Bi-Metalic arent really that trustable. Get yourself a good glass lab thermometer (not a cheap Chinese one).
My local stocks Alla from France for $15, they or something similar would be a good call.

There are some other factors that would be worth taking a look at but I would start with temperature.
Mark
 

MHB

Well-Known Member
Joined
1/10/05
Messages
6,855
Reaction score
4,317
Location
Newcastle
I have a Braumeister and its probe is in the bottom floor to.
First thing (after taking it out of the box and fondling it) was to calibrate the temperature. I don’t know the BrewZilla all that well but assume you can do what I did which is to: -
About half fill the unit with water.
Set the temperature to 65oC (~middle of mashing range)
Turn on heaters and pump
Allow to heat and recirculate for about half an hour so it’s really stable.
Measure the temperature and adjust if needed.

Just on measuring, there are a few musts: -
Thermometers come in two types, Total Immersion and Partial immersion (usually 76mm), not using a perfectly accurate thermometer the right way can put you out 3oC at 65oC, make sure you look at the thermometer and use it properly. Mostly for brewing we use total immersion; the whole thermometer should be immersed in the liquid you are measuring.
Don’t hold the bulb close to an element or you might get some localised heating and an error.
Leave the thermometer in the hot water for 10 minutes or so before taking a reading, the glass that the thermometer is made of needs time to heat up to, not just the liquid in the bulb. The thin tube where the liquid comes up actually changed diameter (slightly) with temperature, if it isn’t at the right temperature again some error can creep in

I usually hang my thermometers on a bit of thin TIG wire, just to make it easy to grab.
Mark
 

clickeral

Well-Known Member
Joined
12/4/14
Messages
254
Reaction score
70
Location
Victoria Australia
Thanks Mark

I've ordered the thermometer and I'll see how I go. I have tried something similar but using a better thermometer may help

Cheers
Nick

You can also use Ice water or boiling water to check calibration, if its 100C when the water is boiling, or 0C in icewater (I normally use both to check) then it should be fine
 

Will2233

Well-Known Member
Joined
10/6/18
Messages
45
Reaction score
17
Location
Engadine
Hi all

I have been AG brewing now for just over 12 months. I generally buy AG recipe kits from BeerCo and I follow the recipes to a tee. The last 3 brews I have done I have missed the OG and FG of the brews and I am after some pointers about what I could be checking to get a more accurate outcome. As an example a Double IPA recipe I am currently fermenting missed the OG by 16 points (my OG was 1061 the suggested OG on the recipe was 1076). The previous brew, a milk stout, my OG was 1060 (recommended OG 1067) and my FG was 1022 (recommended 1016).I am using a Brewzilla and fermenting under pressure in an allrounder.

Don't get me wrong the beers still taste great, however it seems that I am ending up 2% short on ABV for my last few brews and am keen for some pointers on what I could be doing wrong, or what I could possibly tweak.

One thought is I need to calibrate my Brewzilla (seems to be showing 103 on the display when setting to HH for boil. if it is 3 degrees out that would affect the temperature I am mashing at, but would that make that much of a difference?

I look forward to receiving any and all advice.

Cheers
Hi, I had a similar thing happen to me.
After asking for ideas from forum users and much head scratching I realised that inadvertently I had over time changed the equipment profile.
What program are you using also what size Brewzilla.

William
 

Will2233

Well-Known Member
Joined
10/6/18
Messages
45
Reaction score
17
Location
Engadine
Hi William

I am not using a program :as yet". Purely following the All Grain recipe.

The Brewzilla is 30L.
Are you able to post the ingredients and I can input them into brewfather using the profile i use to see what BF comes up with.
William
 
Joined
1/5/20
Messages
45
Reaction score
8
Location
Hazelbrook NSW
Hi William, I really appreciate this. Below is the recipe I used. BTW I have a Brewfather account but have not yet used it.
Vital Stats:
Batch & Boil
  • Batch Size: 19 L US 5 Gallon
  • Boil Time: 90 min
Properties
  • OG 1.076
  • FG 1.014
  • IBU 110
  • ABV 8.3%
  • Colour 16 EBC
  • Balance - 1.445 IBU/SG
Malt
AmountFermentable% GristUseColour
5.00 kgMalteurop Pilsen Malt77%Mash4 EBC
1.00 kgCrisp Vienna Malt15%Mash7 EBC
0.50 kgCrisp Amber Malt8%Mash65 EBC
Hops
AmountHopTimeUseAAIBU
100 gRakau NZ Hops60 minBoil9.1 %91
50 gNelson Sauvin NZ Hops5 minBoil9.7 %10
50 gRakau NZ Hops5 minsBoil9.1 %9
25 g Nelson Sauvin NZ Hops3 daysDry Hop9.7 %0
25 gRakau NZ Hops3 daysDry Hop9.1 %0
25 gNelson Sauvin NZ Hops3 daysDry Hop9.7 %0
25 gRakau NZ Hops3 daysDry Hop9.1 %0
Yeast
Method:
1. Mash - Add 17 Litres of Water or a Liquor to Grist Ratio of 3:1 at 73C for a Single Step Infusion Mash at 67C and hold for 1 hour or until mash conversion is fully complete.

2. Mash off - Infuse mash with near boiling water while stirring or with recirculating mash system raise temp to mash out at 76C for 10 minutes.

3. Fly Sparge slowly - once again the brewer should do normal sparge regime with approx. 15 Litres of Water at around 76C to end up with a pre-boil volume of 25 Litres in the Kettle

4. Boil - vigorous boil for 90 mins due to high proportion of the grist that is Pilsener Malt.

5. Boil Hop additions - take note of Hop additions. 100g of Rakau at the 60 minutes from end of boil mark and 50g each of Nelson and Rakau at 5 minutes from flame out.

5. Yeast & Fermentation - The wort should be chilled to a temperature of 18-22°C or below before you pitch your yeast and ferment around 18-23°C

6. Double Dry Hop Additions - Add the First Dry Hop additions of 25g each of Nelson and Rakau post Krausen falling and primary fermentation around the Day 5 mark and let sit at around 18-23°C for 3 days before the Second or Double Dry Hop addition 25g each of Nelson and Rakau and leave for a further 3 days until fermentation is fully completed.

5. Conditioning and Bottling or Kegging - Rack the beer off the yeast after primary fermentation is complete and cold condition for 2-3 days below 5°C at or near 2°C is ideal post secondary fermentation and dry hop to clear up the beer as much as possible for racking.
 

Will2233

Well-Known Member
Joined
10/6/18
Messages
45
Reaction score
17
Location
Engadine
My BF gives a OG of 1.061 which is what you ended up with.
Lets see if my method is wrong.
There are smarter people than me on here.
William
 

Attachments

  • Brewfather_OG_20211011.pdf
    109.7 KB · Views: 11

MHB

Well-Known Member
Joined
1/10/05
Messages
6,855
Reaction score
4,317
Location
Newcastle
Just a quick finger count puts the Kettle Gravity at the start of the boil at around 1.060 at fairly high efficiency (95%).
If you boiled down to 19L that puts you OG close to 1.070. Personally I suspect whoever wrote the recipe is being just a touch ambitious. That would require a boil off of 13%/hour or so for 90 minutes
What is a concern is the FG, finishing that high and getting lower than anticipated OG does point to too hot a mash.
Temperature has the biggest influence on the mash (by a fair wack) and it’s easy to check. It should be checked regularly against a reference.
If that puts him back on track, good, if not there are other places to look but always go for the basics first.

It’s a really god idea to learn a bit of the basics of brewing rather than being a software pilot.
Mark
 

Will2233

Well-Known Member
Joined
10/6/18
Messages
45
Reaction score
17
Location
Engadine
Just a quick finger count puts the Kettle Gravity at the start of the boil at around 1.060 at fairly high efficiency (95%).
If you boiled down to 19L that puts you OG close to 1.070. Personally I suspect whoever wrote the recipe is being just a touch ambitious. That would require a boil off of 13%/hour or so for 90 minutes
What is a concern is the FG, finishing that high and getting lower than anticipated OG does point to too hot a mash.
Temperature has the biggest influence on the mash (by a fair wack) and it’s easy to check. It should be checked regularly against a reference.
If that puts him back on track, good, if not there are other places to look but always go for the basics first.

It’s a really god idea to learn a bit of the basics of brewing rather than being a software pilot.
Mark
I don't know if your referring to me as "being a software pirate" MHB.
I was only trying to go some way to get to the root of the HazyNicks problem the only way I could, if the grains were never going to achieve the OG specified that could go some way to explaining the problem.
William
 

MHB

Well-Known Member
Joined
1/10/05
Messages
6,855
Reaction score
4,317
Location
Newcastle
I don't know if your referring to me as "being a software pirate" MHB.
I was only trying to go some way to get to the root of the HazyNicks problem the only way I could, if the grains were never going to achieve the OG specified that could go some way to explaining the problem.
William
I meant Pilot, as is in one who drives software. As is in opposed to not knowing enough about brewing.
The OP has a problem with his last few brews, Low OG and High FG, the simplest explanation is he is mashing too hot. Yes there are other possible explanations or contributing factors but temperature needs to be addressed first!

Look at the Recipe; it has 6.5kg of malt. Malt Europe Pilsner is a great malt with a high potential somewhere around 80%, add the other bits and the grain bill will have a potential of around 78%. This means there is a potential of getting 6.5*0.78=5.07kg of extract into solution (give or take a couple of points).
If you got all that extract into the kettle at the start of the boil (100% efficency), in 25L by applying the standard formulia.
Mass of extract = Volume * SG * oP
5.07 = 25*SG*oP, solve for SG and oP given SG=(4*oP)/1000+1
You get a kettle full gravity of 1.0754 or 18.86oP at 100% yield.
So there is plenty of grain there to get the gravity given in the recipe, no matter what BF has to say.

If there wasn’t enough grain in the recipe, you would be right, but there is plenty of malt.
Sorry I'm getting a bit sick of all the software rules BS here. If you want to brew you need to learn the basics of the craft. Like any hobby or even profession, there are fundamentals you need to learn if you want to be good at it.
Software and Bling don’t make beer, brewers do.
Mark
 

duncbrewer

Well-Known Member
Joined
8/12/19
Messages
548
Reaction score
199
Location
paremata nz
@HazyNick
You mention your gravity readings but no mention of volume or any intermediate readings of volume or gravity in your process.

High gravity beers are a challenge on a 30 litre system such as the brewzilla with all grain to get the sugars out of the grain and into the boil. I'm not that sure that a 90 min boil because of a high proportion of pilsner malt is that relevant these days.
Having used a robobrew and now moved on, the conversion and pre boil efficiency is useful to know. But as @MHB says the high final gravity is more suggestive of too high a mash temperature and too few fermentable sugars for your yeast. I found I got better pre boil by using more than 3 litres per kg of mash water and a smaller sparge. The sugars were there but probably never made it to the kettle and a lot that did were too big for your yeast to use well, especially with the added stress of pressure. I do pressure ferment, but not not from the off in all cases, Verdant IPA is a hungry active beast that's very expressive, why squash that with a pressure ferment. You might as well use 05 .
There are so many variables to " optimise " a brew, you follow the recipe to a tee. But what's the water treatment, what's your water, what pH do they suggest and you get. What's the grain crush like? How is your temperature control, do you add yeast nutrients.
That's a challenging beer kit you are buying there and you probably can get the same gravity and taste by spending a lot less on malt and hops and electricity.
Calibrating your brewzilla temp is essential and should be a regular occurrence but I've found it is not as simple as some recipes would have you believe.
Next time you brew a high gravity beer finish the recipe instructions and put your malt pipe over a bucket and squeeze the grains down. Pour 6 litres of boiling water over the grains slowly and leave it to drain overnight. In the morning check the runoff gravity and you'll be surprised how high it is.
 
Joined
1/5/20
Messages
45
Reaction score
8
Location
Hazelbrook NSW
Hi everyone

Some great advice, thank you. Some of it is above my current investment in understanding brewing techniques and numbers. I will definitely be checking the temperature and recalibrating if required and looking at progressing my brewing knowledge.

It would be interesting to know the best time(s) to check gravity and volume? ATM I take my first gravity check when transferring to the fermenter and then start my FG readings around 10 days after that.

In regards to PH etc, I have just started using salts to balance the water and use Brewing Water Chemistry Calculator - Brewer's Friend to help. I am hoping this is working somewhat and I look at the Sydney Water website to get the readings.

I allow my fermenter to naturally pressurise, which usually happens around 3 days into fermentation.

By the way, I have only brewed three beers to date using this fermenter, any reading that you would recommend would be appreciated.

Cheers
Nick.
 

duncbrewer

Well-Known Member
Joined
8/12/19
Messages
548
Reaction score
199
Location
paremata nz
@HazyNick
Lots of info here for you ( and the rest of us).

A check of gravity and volume after runoff ( temperature compensated) will give you info on your mash efficiency, essentially on your system this will be pre boil gravity and vol so pre boil efficiency ( if you aren't sparging).
Post boil gravity and volume and continue with volume and FG in the fermenter.
Remember to correct for temperature with your gravity readings, wort does need some cooling usually to less than 50 celsius before putting hydrometer in.
You'll probably find that ferment with airlock for first 3-4 days and then put the dry hops in and a spunding valve on will give your yeast more of a chance to shine. But beware verdant IPA yeast not under pressure will be very active see this thread

Pressure fermenting I'd have a good look at David Heath homebrew on youtube ( for lots of brewing info and tips) has pressure fermenting there as well.
 

Latest posts

Top