Why/how would the specific gravity increase?

[kvothe]

This is my first post! I'm excited to be part of this community. So far I have only leeched advice while homebrewing, but now, I have a problem that I can't find anywhere on the internet. Thanks for the help.

The Problem:
my mead's specific gravity increased from 1.076 (original) to 1.095 (60 hours after pitching yeast).

My thoughts:
1) this could be that my original gravity reading lacked yeast, and after the yeast started multiplying, the mead's density increased. So, when I checked the gravity to log its progression there was more "stuff" in the water.
2) maybe there was undissolved honey at the bottom of the carboy that slowly dissolved in the last 60 hours, thereby increasing the specific gravity.
3) I put spices (cloves and nutmeg) in mead, and they've slowly been dissolving over the last 60 hours, and now the gravity is reading higher than the must's.

The Recipe:
Montrachet yeast
12 lbs of wildflower honey
2 tsp acid blend
4.5 tsp yeast nutrient
1/2 tsp grape tannin

Any knowledge out there you can humble me with regarding my problem?

Thanks

 

[cluckk]

The Problem:
my mead's specific gravity increased from 1.076 (original) to 1.095 (60 hours after pitching yeast).

Thanks

The higher reading simply means your hydrometer is floating higher because the liquid is heavier or because something is lifting it. I know that sounds insultingly patronizing but I don't mean it that way. The reason I say it is because I figure that 60 hours into your fermentation you have so much yeast activity going on that the yeast and the CO2 they are putting out is floating your hydrometer higher. Wait until fermentation settles down before taking any readings, unless you are going to cold crash and degass the sample.

Go with your original reading and wait longer to take another.

 

[damdaman]

Could be #2 as well, the fermentation churning everything around would mix in that honey settled on the bottom more.

 

[kvothe]

Thanks a lot for your help. As long as nobody is saying "yup, an increase in sp. gravity is definitely bacterial contamination" then I'm fine.

Cluckk,

Thanks for clarifying that you were not being patronizing. I know it can be difficult sometimes to communicate without heavy implications. The written word is an craft and an art as well. You friend, are an artist.

Now i know. I shall store this knowledge for years to come. Thank you.

 

[ianw58]

Thanks for clarifying that you were not being patronizing. I know it can be difficult sometimes to communicate without heavy implications. The written word is an craft and an art as well.

Good attitude! It is tough to be sure, sometimes. Just give 'me the benefit of the doubt.

And...actually, a bacterial infection will almost always reduce the specific gravity. The infection will "digest" the sugars in the liquid, breaking them down.

What size batch is this? 6 gallons?

 

[ace1719]

The higher reading simply means your hydrometer is floating higher because the liquid is heavier or because something is lifting it. I know that sounds insultingly patronizing but I don't mean it that way. The reason I say it is because I figure that 60 hours into your fermentation you have so much yeast activity going on that the yeast and the CO2 they are putting out is floating your hydrometer higher. Wait until fermentation settles down before taking any readings, unless you are going to cold crash and degass the sample.

Go with your original reading and wait longer to take another.

Dissolved gasses will actually decrease the SG. On multiple occasions I've noticed that after shaking a brew to get CO2 out of solution, the gravity increases.

 

[MarshmallowBlue]

Temperature can make it increase but .20 is too high for that. What I think it may be (not sure how you made your batch;

Honey was not fully dissolved into solution and sitting on the bottom in higher density, lowering the gravity of your sample. In that time it dissolved into solution and balanced the gravity throughout.

 

[Complete_Amateur]

Dissolved gasses will actually decrease the SG. On multiple occasions I've noticed that after shaking a brew to get CO2 out of solution, the gravity increases.

Dissolved C02 increases the density of water (maybe must is decreased by dissolved C02-I'm not sure), but I think it is more the release of the C02 from solution that would cause the false readings (I had the same "problem" with a recent batch - started at 1.083, and my first reading after fermentation began was ~ 1.1). I noticed there were bubbles forming on my hydrometer, and that the reading increased over the course of a couple of minutes. Just like raisins bob up and down in a glass of carbonated water/soda.

I shook the sample and waited for it to calm down and the results were more what I expected to see. You may find the same works for you. If not, then you can be certain you had undissolved honey.

 

[HopSong]

Next time you take a gravity reading, put the liquid (beer, mead, cider, etc) in the hydrometer jar and either let it sit fir awhile.. or, better yet, shake it.. let it settle, shake it, let it settle, etc. Get the dissolved gasses out of it.. Tiny bubbles come out of solution and can cling to the hydrometer and make it ride higher. I JUST had this "theory" confirmed in the Brew Science forum. I had always simply took a sample and put it into the hydrometer tube and took a reading... as I think 90+% of us do... never giving a thought to dissolved gasses. Then, bam, it hit me... so, to confirm it, I asked in Brew Science.

This may/not be your problem.. but, it will become regular practice for me. Simply twirling the hydrometer to release bubbles is now out of my process.. except doing the SG reading.