Efficiency

[HopGrower]

Anyone else having their grains crushed at NG and getting really low efficiencies? My last batch had a beersmith estimated OG of 069 and a measured OG (just before pitching) of 042.

[amartin]

Was this a one time thing, or more often? Also, which location are you going to?

[HopGrower]

The last 2 were quite low. I buy from NG in burnside.

[RubberToe]

What was your grain bill? The difference between 069 and 042 are huge, more than a shitty crush will give you. However, the crush is one of the largest factors effecting efficiency.

Check this out: http://braukaiser.com/wiki/index.php?ti ... on_mashing

Could your mash temperature be off due to an uncalibrated thermometer? I'm assuming you did a 60 minute mash? Are you 3 vessel or BIAB?

[sleepyjamie]

If you are worried get them to double crush next time

[HopGrower]

Possibly. I just use a mercury thermometer, no real way to calibrate it.

10lb pils, 1lb aromatic, 0.5lb munich, 1lb cane suger, 3-vessel system.
I'm probably doing something wrong; I just wanted to see if anyone else had complaints about NG crushing, just to rule it out. The crush didn't look bad.

I don't have a pH meter yet.

[amartin]

They crushed mine for years, and I usually had fairly good efficiency before I switched to batch sparging. Their mill isn't adjustable either, so I don't think that would be the problem.

[amartin]

I don't have a ph meter either, but based on your recipe and the water here I doubt that would matter much anyway. How are you measuring your volume? Are you leaving a lot of wort behind in the kettle?

[RubberToe]

Take this with a grain of salt (I do no-sparge) but could you be sparging too fast?

[amartin]

Also, how are you sparging, fly or batch?

[Jimmy]

What was your final volume like as compared to what you were aiming for? Were you short on volume, or did you have more than expected?

[HopGrower]

Fly sparged for 35 minutes. Last batch ran a bit short, but this latest batch hit pretty good for final volume; maybe 2 liters left in the kettle (plus the extra 7 liters below the ball valve.)

[HopGrower]

At this point I think it's my thermometer. I'll pick up a 2nd just to double check things.

Latest batch was a single 150F rest for 60 minutes.

[amartin]

If you're concerned about conversion, you can check a sample with iodine. It takes just a minute and a bottle is cheap (I think) and lasts forever.

[John G]

You can "calibrate" a mercury thermometer by checking it at boiling and add a piece of masking tape around the thermometer with a correction factor written on it. If it is reading 101C at boiling then write -1 on the tape flag to indicate you need to subtract 1 degree from the reading. We do this all the time in our lab since no thermometer is perfect, although you'd have to be off by quite a bit to get that difference in efficiency during brewing.

[LeafMan66_67]

Just before Xmas I believe NG Burnside made some repairs to their grinder. I noticed my efficiency went up so I asked the question, since my batches were pretty consistent. I've since gotten a mill so don't know if anything has changed there.

[akr71]

Possibly. I just use a mercury thermometer, no real way to calibrate it.

Stick it in a glass of ice water - fill the glass with ice, top up with cold tap water to fill the spaces. It should read pretty close to 0. Then take a reading in boiling water. Then you will know how far off you're thermometer is at both ends of the scale.