fermentation not finishing

[SmithyA]

I've been reading a bit about oxygenating your wort with an air stone and a bottle of oxygen. Feedback from users adopting this method is a better hit rate on their FGs. I struggle to hit my target FG with my splashing technique so will be upgrading (out of frustration!) to using a bottle of oxygen, regulator and air stone.

 

[MHB]

Good aeration is important but it wont change non-fermentable dextrins into fermentable sugars.
The fermentability of a wort is primarily a product of your grain choices and mash regime. The single best investment most AG brewers can make is a good thermometer, not a digital one but a good glass lab thermometer use it as a reference and calibrate any other thermometers from it.

In truth if it was a degree or two out it wouldn't matter, you will be adjusting your recipes according to taste and being consistent is the main concern.
I have seen cheap thermometers that were 20oC out (landfill) but of dozes of decent thermometers (mostly English and French) I have handled I have never had one that was more than 1oC out, they cost less than $20, a very good investment.
Mark

 

[Bribie G]

Mark, can you recommend some brands / suppliers? The reason I went to digital thermometers was because my glass thermometer, from a LHBS, turned out to be 8 degrees out. I also need accurate thermometers because I don't drink plain milk but make yogurt and kefir that have to be pretty spot on.

I've been calibrating my digitals with boiling water and melting ice and they are actually pretty good, I have bought from good quality kitchen shops not ten buck jobs off ebay. However having an accurate lab thermometer as a "master calibrator" for all the intermediate ranges would be the ducks.

 

[Zorco]

I'm totally in for a group buy of a single reference thermometer. We all throw in $5 and come away with a ripper. Then we post it around to the people who want to check and verify their readings. An amount of trust but we have a log, use registered mail.

I'm sure we could knock up an AHB quality and Verification trust where we are all registered participants.

 

[philistine]

THERMAPEN

 

[SBOB]

THERMAPEN

+1 to this..
grab one when they do clearance of seconds or box damaged ones.

Mine matches my Anova Sous Vide machine to the 0.1c, and its very fast to give accurate readings.

 

[MHB]

I know Steve carries good ones at Brewman, I think they are mostly Alla French made, because those are the brand his wholesaler stocks. When he started running Brewman we had a conversation about just this subject, as Steve is a chemical engineer so it wasn't a hard sell. I have found them excellent.

The reason I am recommending a glass lab thermometer is that they don't get flat batteries, wet contacts, internal corrosion, kinked wires... which anything electronic can do without your being able to tell. A glass thermometer either works or is broken, it doesn't change or drift - again without you knowing.

I have several sensors both analog and digital and regularly calibrate them against my reference thermometer, a pH meter that I calibrate before use, when I had a shop I has a 5, 9's kg mass to calibrate my scales - just part of doing it properly!

Like I said above you are only looking at somewhere near $20, I think the idea of posting one around would be a bit counterproductive, it would cost at least $10 per movement so with the $5 you put in, I cant see the saving being worth the effort. A NATA certified thermometer will cost about $400, it would probably be the same thermometer as the $20 one with a foil sticker - just get one from a reputable shop, make sure it isn't a $2 Chinese jobbie, no the don't bend or bounce but with care they last a life time.
Mark

 

[Zorco]

I think you're right overall Mark and happy if there is no interest.

I looked at the specs of the thermapen and it looks OK too.

I think that if I went for a reference thermometer it would be a Fluke though.

We have a NATA accredited lab downstairs, I might just see what they have.

 

[MHB]

Fluke and Zeal are both good, I'm sure lots of others. If you have a NATA lab see if they can check yours against theirs.
When quick and precision matters I use the thermometer in my pH meter, and yes Thermapen have a good name, mind you at the price you could probably go a long way toward a very good pH meter with thermometer and possibly conductivity meter built in - choices, choices...

None of the above makes any difference to what I would recommend - get a good glass lab thermometer and use it as a reference!

Mark

 

[Ditchnbeer]

If you are not reaching your expected FG then adding oxygen via bottle or aquarium pump will definitely help. But also ensure you are pitching enough quantity of healthy yeast - like making starters, buying fresh packets, thinking about 1.5 packets instead of just one (depending on the style). And then if you have fermented at 20, when ferment is finished, raise the temp to 22 for 2 days just to help the yeast finish up.

Having a routine of using starters, and increasing temp at the end of ferment has assisted me in obtaining expected FGs.

 

[barls]

If you are not reaching your expected FG then adding oxygen via bottle or aquarium pump will definitely help. But also ensure you are pitching enough quantity of healthy yeast - like making starters, buying fresh packets, thinking about 1.5 packets instead of just one (depending on the style). And then if you have fermented at 20, when ferment is finished, raise the temp to 22 for 2 days just to help the yeast finish up.

Having a routine of using starters, and increasing temp at the end of ferment has assisted me in obtaining expected FGs.

but if the reason your not reaching it is the amount of long chain sugars your making in the mash all the yeast and oxygen isn't going to help as most are unfermentable by the cerevisiae strain

 

[Zorco]

A quarter of a million dollar electron microscope but no thermometer!

I didn't know about pH combo. New angle, cheers