Diagnosis for repeated missed FG

[Dack]

I've had problems with my last three batches not hitting their predicted FG, despite my technique and equipment getting better. I'm aware I was pretty sloppy with my first few AGs, but even then they still hit their predicted FG (half the time they over-performed!)

The worst example was a Landlord clone I tried a month ago, which is now somewhere in the Edinburgh plumbing system. My process is:

Boil mash water the night before with half a campden, leave it covered and raise to strike temp the next day.

Add strike water to mash tun several degrees above the calculated temp to allow the tun to warm up. When cooled to the right temp, dough in with grains. Let stabilise at 66degrees Cover up with blankets, bind with bungee cords, make a cuppa (important!).

An hour later, take a few drips sample in a saucer, do an iodine test. Once completed, start run-off. Add sparge water at 77degrees, collect run off until total volume is collected/adjusted SG falls below 1.008.

Start boil, add hops and all that jazz. Add immersion cooler in the last 20 minutes of the boil to sanitise it, then cool the wort. (Make another cuppa.)

When cooled to pitching temp, drain copper through hop filter into fermenter, giving it a good stir with a sanitised spoon to aerate it. Check OG, which is usually bang on, or a off by a couple of points at most.

Pitch yeast from starter, add sanitised aquarium heater, feel chuffed.

A few days later, there's a big healthy krauesen and everybody's happy. A week later, check gravity. In the last batch, it was 1.022. A few days later, still at 1.022, not the target of 1.010.

I thought the problems would be either under pitching yeast (I switched to using White Labs vials, for the first one I pitched it straight, after it underperformed I went back to making a starter); or poor aeration (but I've been stirring the bejesus out of the cooled wort prior to pitching...

Any ideas? It's turned into a bit of a stumbling block. (Apologies for the wall of text.)

[Dack]

Oh, should add, I've taken to adding 1/2 tsp of yeast vit to the wort as I'm aerating it, just before pitching the yeast.

[Beer O'Clock]

What strain of yeast ? What temperature are you fermenting at ?

I think if you let the yeast do it's THANG and don't try putting time constraints on it, it will reach target. I noticed when I changed to liquid yeast that there was a difference in "lag" times and length of fermentation time. I regularly leave for 14 days before I bother to test the gravity.

[Beer O'Clock]

This also might give you an idea viewtopic.php?f=2&t=50734

[Dack]

The last three strains I tried were WLP001 Cali Ale, WLP090 San Diego Super, and WLP005 English Yeast. The English one was the most recent and most disastrous, the other two got close enough to the FG that the beer was close to style.

I usually ferment at 20-21 degrees, which is about the mid- to upper-temperature for most ale yeasts (correct me if I'm wrong!).

I agree with letting the yeast get on in peace, however the Landlord clone I just binned was left undisturbed for 4 weeks, stuck at 1.022. No amount of rousing helped (WLP005 is a very highly flocculating bugger, so I thought that was to blame...)

[Fuzzy]

How accurate is your thermometer as if your are mashing at too high a temperature then that can cause more unfermentable sugars in the wort. You can check a thermometer by doing the crushed ice test, google it for info. Hope that helps.

[Mitchamitri1]

Agree with the last post - check your thermometer, only other thing I would do is try a different yeast altogether - even though a brewery might say it has been using the same yeast since it opened 500 years ago, technically its an evolving fungus so no two will be 100% the same. Maybe the yeast you are using has suddently decided it doesn't like your water? Don't stress on the aeration too much.

I normally ferment at....er.....room temperature for as long as.....er.....till it's done or I get round to kegging it, have had beer sat for 8 weeks plus before kegging and it has been fine, stuck fermentations usually release themselves after a few days.

[Dack]

It's entirely possible that my temp controlling for the mash hasn't been especially brilliant for the last couple; I was using a laser thermometer that really wasn't up to scratch. I've since switched to a decent probe designed for liquids, so hopefully this batch will show some promise!

It's my first attempt at reusing a yeast that I'd rinsed and kept in the fridge, so fingers crossed...

[Mitchamitri1]

I have used my daughters ear thermometer more than once to measure wort temp. So I guess its an aural proble!

[scuppeteer]

I do find that these fancy thermometers don't always perform as they should, try the old fashioned glass jobbies as a back up and take a reading with the fancy one and glass to make sure. You may find quite a difference.

[yojimbo]

Have you checked your hydrometer the paper inside ccan move sometimes as its only last 3 brews I would start there if you not changed anything in your brewing process.

[Dack]

Well gents, looks like the problem really was down to piss poor temperature control: the newest batch has shot down to 1.008 in four days! Goes to show, always take a temperature reading from a probe thermometer if you want accuracy. Happy days!