Constantly getting over attenuation with starters.

[beskone]

So I've had this issue for a while. I'll make a 1L starter for a brew that has a OG of around 1.050-1.069ish

Even so, I'm over attenuating by 5 - 8 points almost every time.

My last pale ale, WLP001 OG 1.055 Expected FG 1.011 Actual 1.005

My last wheat ale. WLP320 OG 1.048 Expected FG 1.014 Actual 1.006

If I go by what MrMalty says, I need at LEAST a 1.5L starter for both.

With the 1L starters I'm getting fast fermentations that finish up fine but just over attenuated.

I'm confused, wouldn't making an even bigger starter contribute to even greater over attenuation? It's not like I'm getting weak fermentations, they're actually extremely vigorous.

 

[kombat]

Have you checked your thermometer? I wonder if maybe it's reading a few degrees high, and perhaps you're actually mashing lower than you think you are, creating a more fermentable wort.

 

[beskone]

I don't think that's it. It's a Thermapen that's dead on accurate.

I mashed the pale at 152, the wheat at 158.

 

[blizz81]

Dang. 158, and ended at 1.006?


Do you lose temp in your mash tun at all?

 

[kombat]

How are you measuring FG?

 

[kh54s10]

How are you measuring FG?

This ^^

If you are measuring with a refractometer the reading has to be run through a calculation due to the presence of alcohol.

If a hydrometer is the sample at the temperature the hydrometer is calibrated for. Usually 60F.

 

[beskone]

How are you measuring FG?

With a Hydrometer, measuring at ~60º which is the calibration temp.

I have 4 different ones and I've verified they all read the same.

 

[beskone]

Dang. 158, and ended at 1.006?


Do you lose temp in your mash tun at all?

It's a 10 gal Igloo, so maybe 1º over 60 minutes.

 

[beskone]

Also it's not with every brew.

I did an IPA with Conan and hit the expected attenuation dead on.

Although people seem to have attenuation trouble with Conan, so it still might be a theme here if I'm getting more than expected.

WLP001 always over attenuates. like 90-95% when it should be down closer to 80-85%

It's just weird.

 

[Calder]

First, have you checked your thermapen reads right?

A thermapen is relatively short. Do you know your mash is the same temp at the bottom?

Sounds like a temp issue to me.

 

[Queequeg]

Temperature varies significantly across the mash bed. Are you doughing in enough i wonder?

Also what calculation are you using for the starter? Try kaisers on brewersfriend

 

[CA_Mouse]

I have seen this with WLP001, WLP007, WLP090 and WY1056. Especially if I've mashed below 154*F. Also, what temperature are you fermenting at? I lowered mine to between 62*F and 64*F. This gets my attenuation closer to what BeerSmith calculates it to be.

 

[beskone]

Temperature varies significantly across the mash bed. Are you doughing in enough i wonder?

Also what calculation are you using for the starter? Try kaisers on brewersfriend

I'm using 1.25qt/lb for the mash. I stir the **** out of it when doughing in and stick the thermapen as deep as it'll go and stir it around for about 15-20 seconds before taking a reading.

I was looking at just the MrMalty .75 for ales starters. Like I said I was making 1L starters for these which according to that would be under pitching.

 

[beskone]

I have seen this with WLP001, WLP007, WLP090 and WY1056. Especially if I've mashed below 154*F. Also, what temperature are you fermenting at? I lowered mine to between 62*F and 64*F. This gets my attenuation closer to what BeerSmith calculates it to be.

Hmmm, maybe I'll try mashing above 154 then with WLP001 next time.

I usually ferment around 66º The Conan batch I actually started at 64º so I can try that next time as well.