Fermentation Gravity Issue - Help

[JB-J]

Hi All,
I have been brewing all grain for a few years now. However, there is one issue that has been pretty consistent. My gravities have been off.
Sometimes from mash and sometime from fermentation and sometimes both. They can veery by 1-2 points.

Mash issue:
For example, if my OG is shooting for a 1.088. My post-boil wart may be 1.078-1.068.

Fermentation issue:
My 1.078 ferments down to 1.032 = 6.2% ABV. Ugg, I was hoping this beer would be 9%.

I am generally making 5 gallon batches of IPA and DIPA using a cooler mash ton and fermenting under pressure with a fermentasourus with good temperature control. I calculate cell count required and use starters when necessary and like to use new liquid yeast.

Any thoughts are appreciated.
~J

 

[GoeHaarden]

A couple of things...

If you take pre-boil gravity readings it can help you decide whether to add some malt extract or boil longer to achieve your desired OG. This can also give you an idea of what your conversion/mash efficiency is and you can adjust subsequent grain bills to account for low efficiency. Which may be why you're not hitting your numbers...

Do you adjust your water? Mash pH may be hindering your conversion as well...

Lastly. What are you measuring your FG with? When I see someone saying their beer stalled at ~1.030 I immediately think that they are using a refractometer. Maybe you already know this but refractometer readings need to be adjusted when alcohol is present...I only use my refractometer on brew day, and take FG readings with a hydrometer.

If you're using a hydrometer and you're using the right pitching rates, then I would suspect you're mashing at too high temperatures producing more unfermentable sugar chains. Check and recheck you're thermometers with a known accurate one. Thermopens are the way to go!

Cheers!

 

[JB-J]

GoHaarden,
Thank you for the response. In fact, I do most of my gravity readings with a refractometer. I was not aware that they respond differently compared to a hydrometer when alcohol is present. I did make sure that the refractometer was calibrated correctly and did see similar results between both the the refractometer and hydrometer when I was last using both.

I have played with adding a two more pounds of grain to the to the gain bill to help with efficiency but the results have been negligible. Maybe, I will add more then 2 lbs next time to test.

I do not adjust water at the moment, with the exception of a half of a camden tablet. The mouth feel on my beers is good so I haven't been driven to change it.

I do not currently take pH readings but plan too in the future.

I mashed my last Double IPA at 145 and it was stable for the 60 minute mash schedule. This was the lowest mash temp I have ever used but this was a NE DIPA. I will look into the Termopens. I currently use a CDN brand digital thermometer but will take your advice to check and recheck them for acuraccy.

Additionally, I am using a batch spare technique.

Thanks again.

 

[GoeHaarden]

Yeah, if you use a calculator (https://www.brewersfriend.com/refractometer-calculator/) with the numbers you provided, your gravity is more like 1.006. Who knows how accurate these calculators actually are, and therefore I just use the trusty hydrometer for FGs.

If you've had negligible results adding more grain, then I would look into the crush you are getting. If you use the same source for your grain and milling, then I'd say that your crush is not as fine as it should be. Try a new source, or ask them to crush twice...

You don't necessarily have to adjust your water, but just know that mash pH can effect a lot of things including starch conversion. I don't use a pH meter either, I just use Bru'n Water and I haven't had any issues. Also, this is a good place to start: https://www.homebrewtalk.com/forum/threads/a-brewing-water-chemistry-primer.198460/

FWIW. I've reverted back to batch sparging lately, and have been getting around 80% efficiency so don't think this technique is inferior to others...

Cheers!

 

[JB-J]

GoHaarden,
Thanks for the links. I will certainly use them.
I had been thinking the same thing regarding grain crush. I usually source my grain and have it crushed by the fine folks at morebeer. A grain mill and pH meter are on my list for my next purchases.

Any thoughts if it could be attinuation and the yeast falling short?

Cheers,
J

 

[GoeHaarden]

I use MoreBeer from time to time, and I feel like they do a pretty good job at a "universal" type of crush that is pretty consistent. I never see a drop in efficiency with them. They are a stand-up company, and I would be surprised if this was your issue. Honestly. Are you using their kits?

Well, I would start by using a hydrometer for FG readings and see if you are actually having attenuation issues.

I'm no NEIPA expert, but what is the recipe of this brew? Maybe the recipe is the issue...

 

[JB-J]

GoHaarden,
Sorry for the delay. Its been a busy week. I do use some of the moreover kits but I also create my own. I have done their Hazy Craze a few times and there More Haze recipes. Both are great and get nice reviews from friends and family.

I am going to dig into FG readings more with the hydrometer and get a pH reader so I can start documents what I am hitting. I just purchased BeerSmith this week so I have a better tracking system. Thanks for all the help and happy brewing to you.