Under-attenuating.....looking for input/ideas

[Pudge]

I am somewhat similar except I have fought an over attenuation problem since the beginning of my all grain brewing several years ago. I replaced equipment (thermometer/hydrometer) thinking my readings were simply wrong somewhere. I too ended up adjusting via mash temp. I mash my English Mild 160-162 to keep that 1.036-1.038 beer from dropping below 1.010 with an English yeast strain. I listened to Jamil Zanisheff talk about drying out a Double IPA as low as you can... not to worry about it. US-05 took that beer from 1.065-1.005.

Anyway, I'll just throw some stuff out there and maybe some piece will stick.

--I use both dry and liquid yeast strains. Dry yeast always gets rehydrated in warm tap water straight from the kitchen sink. Liquid yeast generally comes straight from the smack pack (Wyeast). Rarely do I use a starter. Wyeast nutrient goes in with 10 min left in the boil with each beer. Yeast is often repitched. I'll plan my brewing schedule from smaller beer to larger beer based on the same strain... small APA to IPA or brown ale... small lager like a Helles to a Bock or Maibock. Every strain becomes more aggressive with each generation so I don't keep them around long.

--I ferment in a 6.5 gallon glass carboy inside a digitally temp controller 5 cubic ft chest freezer. Since it is a closed container, I don't use an airlock... just a very loose aluminum foil cap. Primary only. Never a secondary. I tend to get a messy transfer too... quite a bit of sludge. It'll settle out. Yeast is pitched at the lower end of the temp range for any strain of yeast. A stone, filter, and air pump isn't the best way to aerate, but it's what I've used for years. The yeast is pitched (after the desired temp has been reached) and aerated for a minimum of 10 minutes or until foam starts crawling up out of the carboy. The fermentation is held at that temp for 4 days of visibly active fermentation and then bumped up 5-8 degrees for the remainder of 2 weeks... no matter ale or lager.

Oh mash...

I know this method is way wrong, but whatever. I still use a 5 gallon cooler for a mash tun. I run my water volume numbers to fill the tun no matter the water/grain ratio. My goal is to fill the tun in order to reduce head space and hold a solid temp for an hour. That means thinner mash for smaller beers and thick oatmeal consistency on big ones. I'm all over the place. My efficiency suffers with some beers requiring several small sparges in an attempt to get to the wort. Also, plain tap water. I've never done a single water adjustment.

Regardless of all my halfass methods, the over attenuation is there with every beer.

[mashani]

Since it is a closed container, I don't use an airlock... just a very loose aluminum foil cap. Primary only. Never a secondary. I tend to get a messy transfer too... quite a bit of sludge. It'll settle out.

Pretty much this is all the case in my method too, except instead of foil cap I have loose free venting lids. I do know my attenuation went up a bit when I started to semi-open ferment. That's not why I did it, I did it to improve the ester profile of some of the yeasts I use (it does), anything else is just a side effect that doesn't bother me. I don't worry about transferring some break material to my fermenter, it settles out as you say. I have read some folks experiments where they have shown the extra stuff actually improves fermentation compared to leaving it behind. (clarity, maybe not so much but I don't care about that over taste).

[Kealia]

What is your usual fermentation routine? Do you raise temps after 4-5 days of fermentation or just let it ride the whole time at your determined fermentation temp?

I temp control with an STC-1000 and typically start at the yeast's mid-range and ramp up after 5 days by a few degrees.

I've checked my hydrometer in distilled water.

[HerbMeowing]

Must be something going around b/c I be experiencing much the same thing ...
PA/IPAs finishing a few points higher than desired (mid-teens v. low teens).

Beta step-mash temp @ 148°F for 40'
Alpha step-mash @ 153°F for 45'
Target pH 5.3

Fermenting @ low end of US-05 temperature range.
Free-rise to room temperature (low 70s) five days post-pitch.
Under-attenuation seldom happened with liquid yeast (wlp001, wlp002, wlp006, wlp051, wlp820).

Rousing the yeast soon after Hi-K is my latest attempt to 'fix' this problem.
Bottling that batch in two weeks.
Will see.