Hydrometer reading rise

[Singe de l'eau]

My second solo brew is a pale ale with pepper and kaffir lime leaves.
the brew is progressing well and staying around 20° to 22° which is perfect for the yeast (being for an India style ale).

Hydrometer reading was steadily going down over the past 13 days losing 2 points every 2 days starting at 1020, however on day 14 (today) the hydrometer reading has risen from 1010 to 1012. Does anyone have any ideas and or advice?

My theory is that the waxy coating on the lime leaves has broken down and let the yeast at the cellulose in the leaf meaning a hit of sugar for the yeast. There is no infection as near as I can tell but the leaves are white under the surface of the liquid and green where they are above the surface indicating that they have been broken down. (see photo below). Also the smell and taste has become sweeter in the last day or so, also the pepper has become more apparent.

 

[GalBrew]

If yeast could ferment cellulose, then mashing would be a waste of time. I doubt that is the issue here.

 

[Rod]

could be a change in the brew temperature from on reading to the next

 

[user 31093]

If yeast could ferment cellulose, then mashing would be a waste of time. I doubt that is the issue here.

I might ferment some bark chips.
There are probably enzymes available to convert it into glucose, after all it is a sugar.

It could be some other crap from the leaves, but would you have 2 points from it?

I think temp change is a more logical option.

 

[Singe de l'eau]

Today's reading is 1012 but the fermentation is bubbling the temp is at 22°c which is on the high side but considering it was 45° outside it's pretty good.

 

[OneEye]

Did it really start at 1020?

Dissolved co2 can cause the hydrometer to be 'lifted' so to speak. Shake your sample around a little to try and de-gas it

 

[peas_and_corn]

Yeast cannot break down the bonds in wood or cellulose. The glucose molecules are held together with beta 1-4 links, which are incredibly tough (reinforced by covalent bonding) when compared to the alpha 1-4 bonding with sugars

 

[Bribie G]

As the beer attenuates it can put a bit more CO2 into solution, especially if you have cold conditioned it. Maybe CO2 bubbles are "floating" the hydrometer more?

 

[Singe de l'eau]

I'm chalking it up to a combination of the brew temperature increasing the gravity and a miss reading when I put down 1010 with CO2 bubbles "floating" the hydrometer (but I do do a few readings off the one sample each time for that very reason).

But anyway I'm using a brew enhancer so my target gravity is 1011 which it hit today, not 1005, so I've added the finnings and am ready to bottle in a few days.
I'll let you know how it goes.

 

[schrodinger]

CO2 bubbles "floating" the hydrometer

This can be a huge effect. I just took a hydrometer reading; straight out of the fermenter (but after allowing the surface foam to go away), it was 1044. After letting it gas off a bit and ensuring no bubbles were clinging to the hydrometer, it's now 1037. It's not temperature, because the fermentor happens to be within 1 deg C of the air temp in the room.

I kept watching it, and it kept wanting to rise one or two points, each time because a bunch of bubbles were clinging to the hydrometer. Someone should invent a hydrometer surface treatment that prevents bubbles from clinging...

 

[verysupple]

This doesn't have anything to do with the gravity, but it's chlorophyll that makes leaves green. So either something in the beer has leached/broken down the chlorophyll or there's something white depositing on the surface of the leaves. It's hard to say from the photo, but it kind of looks like yeast has settled onto the leaves. Maybe after you package/rack this batch you can pick out a leaf or two and see if it's yeast or something on the surface or if they really did change colour.