Final Gravity always high??

[pale blue pig]

Hey people,

move done two all grain brews in my Brewzilla, and both batches have had the final gravity in the 20s!OG was in the 50s and brewing Pale Ales. Second batch I used two packets of yeast and still got a high FG!? I’m assuming my mash isn’t going to well and converting-enough sugars out?

Can anyone offer any advice/tips??

thanks everyone!

 

[razz]

Hi pbp. If you are looking at mash temps then you will need to check that your thermometer is accurate. Do you have a good quality thermometer or are you just going by the Brewzilla?

 

[MHB]

It's not always one thing, the obvious is that you are mashing hotter than you should be (or think you are).
Said this so many times that I should program an auto text - Every brewer should have one decent quality glass laboratory thermometer that they can use as a reference, point being to check your mash temperature, hotter will give a less fermentable wort.
pH being too high (above ~5.5pH) will also reduce fermentability even if the temperature is right.
Really low L:G (Liquor (water) to Grain) ratios will make for less fermentable wort.
There are a couple of other things but the three above will cover 99% of your issues.

pH is generally a function of water chemistry, I haven't got a clue what the Gold Coast is like but an all base malt mash even with adequate Calcium (50-100ppm) will rarely get much under 5.6 in distilled water. Will always be higher in tap water and it might be worth having a look at your local water, have a play in one of the water programs like Brewin water, or better yet measure the temperature and pH with something you are sure is accurate (Brewzilla is not on that list).
Mark

 

[kadmium]

Hey people,

move done two all grain brews in my Brewzilla, and both batches have had the final gravity in the 20s!OG was in the 50s and brewing Pale Ales. Second batch I used two packets of yeast and still got a high FG!? I’m assuming my mash isn’t going to well and converting-enough sugars out?

Can anyone offer any advice/tips??

thanks everyone!

MHB and Razz pretty much covered it all, but also perhaps clue us in on your process and recipes.

What temps are you mashing? what mash schedule? Mash Out? What's your recipe? How are you recording / measuring gravity? Refractometer or hydrometer? temp corrected?

 

[contrarian]

MHB and Razz pretty much covered it all, but also perhaps clue us in on your process and recipes.

What temps are you mashing? what mash schedule? Mash Out? What's your recipe? How are you recording / measuring gravity? Refractometer or hydrometer? temp corrected?

I'd agree with this, especially the measurement part! I reckon 83% of all process related problems turn out to be a measurement problem and not a process problem!

 

[pale blue pig]

MHB and Razz pretty much covered it all, but also perhaps clue us in on your process and recipes.

What temps are you mashing? what mash schedule? Mash Out? What's your recipe? How are you recording / measuring gravity? Refractometer or hydrometer? temp corrected?

I’ve attached my brew father recipe. I also used rice hulls in the mash . 60 mins at 65 degrees. I’m using a refractometer to measure the gravities.

 

[pale blue pig]

I’ve attached my brew father recipe. I also used rice hulls in the mash . 60 mins at 65 degrees. I’m using a refractometer to measure the gravities.

My OG was 1.053 not 1.060 and final was 1.025 not 1.015.

 

[kadmium]

silly question, but are you sure your refractometer is calibrated, and are you correcting it for alcohol?

 

[pale blue pig]

It's not always one thing, the obvious is that you are mashing hotter than you should be (or think you are).
Said this so many times that I should program an auto text - Every brewer should have one decent quality glass laboratory thermometer that they can use as a reference, point being to check your mash temperature, hotter will give a less fermentable wort.
pH being too high (above ~5.5pH) will also reduce fermentability even if the temperature is right.
Really low L:G (Liquor (water) to Grain) ratios will make for less fermentable wort.
There are a couple of other things but the three above will cover 99% of your issues.

pH is generally a function of water chemistry, I haven't got a clue what the Gold Coast is like but an all base malt mash even with adequate Calcium (50-100ppm) will rarely get much under 5.6 in distilled water. Will always be higher in tap water and it might be worth having a look at your local water, have a play in one of the water programs like Brewin water, or better yet measure the temperature and pH with something you are sure is accurate (Brewzilla is not on that list).
Mark

Cheers Mark, I’ve got the water reports from council and try to adjust to that for the beer I’m doing. But I don’t have a seperate thermometer!! Just going of the brewzilla, I’ll invest it one ASAP!

 

[pale blue pig]

silly question, but are you sure your refractometer is calibrated, and are you correcting it for alcohol?

Yeah I used distilled water to check before using. I’m not sure what you mean by correcting for alcohol? Pretty new to this haha

 

[philrob]

Refractometers need correction for the alcohol after fermentation has started or finished.
Here's a chart to help you figure this out.
It might go some way to help you figure out whether you really do have a problem.
For what it's worth, I don't use my refractometer except for measuring my post mash and post boil gravities.
Once I'm ready to bottle my batch, I use an hydrometer to measure my final gravity.

 

[kadmium]

As a quick rule of thumb, or to check how you do it go to Refractometer Calculator - Brewer's Friend

essentially a Refractometer measures how the light bends when it enters. When you have sugar in the soltuion, it's refractive index changes (refract_o_meter) once you introduce alcohol it screws up the reading, so you need to use a very complicated formula to work it out. The easiest way is to use an online calculator. Beersmith has one.

Essentially, you need to know the original gravity and your now measured gravity and it will convert it for you.

As a quick check, 1.053 to 1.025 is an actual FG of 1.009 which seems about right for a 65c mash.

 

[MHB]

Looks like the problem has been spotted, Plenty of calculators around that will convert into more familiar units, here is a snip from one

To get the Brix (Plato) divide your points by 4 (i.e. 1.053 is 53 Points 53/4 is 13.25, same for FG 25/4 is 6.25).
Looks like you have a pretty healthy ferment and are probably at FG (which is really something like 1.007) and readdy to package.
Mark

 

[pale blue pig]

Haha wow! That easy!! Thanks a lot to everyone who took the time to answer and help out! I had no idea about this! Very fun learning though!
Thanks again! Looks like I won’t have to drink mid strength after all haha

 

[kadmium]

You're welcome mate, that's why it's important to always ask for more info, something I find helps to answer the 1%ers because you may have been chasing your tail thinking it's mash temp.

FYI, I have a Guten and used a good quality digital thermometer and the temp diff between them is less than .5c so don't stress, they are fairly accurate and you should be in the ballpark using a robo etc.

 

[New 2 The Brew]

Wow, just saw this thread. Was having the exact same problem with my refractometer except I also have a hydrometer that measures the true value so I thought the refractometer was broken or I wasn't using it right.

So just to be sure, the wort OG taken with the refractometer is a true reading but the measurement taken after fermentation is false because of the alcohol. I will save that chart but will probably just use my hydrometer.

Really wish they would have included this information with the product.

 

[kadmium]

Hey new to brew, technically the OG is not a true reading, you need to allow for the Wort Correction Factor, as there are other things present in the wort which affect the reading.

I don't use a Hydrometer anymore, I just use a refractometer, you just need to use a calculator. Brewfather, Beersmith etc all have refractometer calculators which are very simple.

 

[johnnybravo78]

Hi PBP, it looks like your on brewfather, if you go into tools tab, there is a refactometer tab, go in that, select fermented wort click box, enter your OG then your current brix%, it calcs the SG for you.
you then can go into your batch recipe and enter the SG into your readings.
sounds a bit much, but is dead easy.
Saves having to drop out a whole tubes worth to use your hydro.