Consistently low final gravity

Hi,

I keep having an issue with not hitting my final gravity. I brewed an ale the other day, recipe was as follows:

8# American 2-row
1# Munich
1/2# CaraPils
1/2# Crystal 40*L
1oz. Cascade pellets (7.1%) at 60 mins left.
1/2 oz. Crystal (4.1%) at 15 mins left.
1/2 oz. Crystal (4.1%) at 5 mins left.

US-05 11.5 gram packet.

5 days at 72* primary fermentation.

OG: 1.045
FG: 1.006!!!

This is the third batch in a row with this problem!

I got a better thermometer (digital probe) after the second f@#k up and the same thing still happened. Am I reading my hydrometer wrong?! Does it need to be calibrated? Is that even possible? Please help!!

Take a hydrometer reading with some distilled water at 60F. If it's at 1.000 you're good. Mine reads 1.004 so I subtract 0.004 from every reading. From what I've read it's pretty common they're off a little.

What temperature are you mashing at?

I will test with distilled water tonight.

The mash was a 3 step.

Protein rest at 125* for 15 mins.
Mash #1 at 152* for 30 mins.
Mash #2 at 158* for 30 mins.

Sparged with 1.5 gallons of 170* water.

Drunk_Mick said:

I will test with distilled water tonight.

The mash was a 3 step.

Protein rest at 125* for 15 mins.
Mash #1 at 152* for 30 mins.
Mash #2 at 158* for 30 mins.

Sparged with 1.5 gallons of 170* water.

Click to expand...

Next time, try a single infusion mash (no reason for a protein rest, or a two-step saccrification rest with that grainbill) at a temperature of 154. Also, are you 100% sure your thermometer is accurate? If you actually mashed at, say, 147-150 (and/or took more than the 15 minutes to reach the saccrification rest) that would explain the low FG.

The previous two were;

123* protein rest for both.

Pale Ale mashed at 158*.

The porter mashed at 156*.

I switched to a probe thermometer with a digital readout because I thought that was the problem originally.

Drunk_Mick said:

The previous two were;

123* protein rest for both.

Pale Ale mashed at 158*.

The porter mashed at 156*.

Click to expand...

How long does it take you to go from the protein rest to the saccrification rest? That could be one of the issues here.

And, it's not really that important but I'm wondering why you're doing a protein rest with that grainbill?

I was told by another brewer that when I switched to all grain that a protein rest and an acid rest would result in a better mash. I am a rookie with all grain and he worked for a brewery at the time so I tool his word for it.

Mistake?

Drunk_Mick said:

I was told by another brewer that when I switched to all grain that a protein rest and an acid rest would result in a better mash. I am a rookie with all grain and he worked for a brewery at the time so I tool his word for it.

Mistake?

Click to expand...

Not necessarily a mistake, but probably unnecessary. with the listed grain bill you probably wont find any noticeable improvements from a complicated rest schedule.
I would calibrate your thermometer with ice water if you havent, also are your volumes you are collecting right on? if you intend to make, say a 5 gallon batch but accidentally collect 5.25 gallons you will significantly skew your numbers (are your O.G. numbers as expected/what kind of efficiencies are you getting?)

My efficiency is usually 75%. I usually collect 5.5 gallons to end up with 5 gallons even after transfers, losing some to the trub, spills, samples, etc. It's usually 6 to 6.5 gallons for a pre-boil.

Thanks for you help everyone. I just did an Irish Stout this past week and did a single infusion mash. The transfer was today and I hit my FG on the nose. 1.016. I am guessing the protein rest and lag time getting it up to my mash temp was the culprit.

What is the big deal if you miss your final gravity number? Does it change the taste of the beer? I just thought lower the fg the higher the alcohol content which make me happy

There is no real harm in missing your FG other than a different mouthfeel or taste depending on the amount. Part of being a better brewer is being able to get close on your gravity readings. Being in the ball park can help you understand how different mash temps work with different malts. Plus if you plan on entering competitions BJCP specs are used for a lot of them. Being within range according to style is important in that respect. If your just making the beer for the sake of making it than there really isn't any harm.