Mash Efficiency

[msppilot]

I am looking for ideas of how to increase my mash efficiency. I have two all-grain batches under my belt now and I have not hit my target O.G. on either. The first time I think the issue was too much water volume, which diluted the wort. The second batch I was more careful about the volume and was close to my target pre-boil volume, although I did not get the boil off I expected. I am pretty sure this had nothing to do with the low O.G. My target mash temperature was 154 degrees and I hit that temp at first but my mash temp did drop to about 147 about half way through the mash. I added about 1/2 gallon of almost boiling water and brought the mash temp back up and added 15 more minutes of mash time. One thing I noticed is my mash is not a consistent temperature throughout the mash tun. I did stir the mash a little during the mash to try and get a more consistent temp. The mash temp did never drop below 146 or 147 and also never was above 160. After 75 minutes of mashing, I performed the mash out, with aprox. 1/2 gal, I lowered the mash out volume because of adding the water to bring the mash temp back up. I then performed a vorlof and a batch sparge with aprox. 4 gallons. I took a pre-boil O.G. measurement with my refractometer and only measured 5 brix, which converted to aprox. 1.023. My target O.G. was 1.058 according to the recipe and 1.072 according to Beer Smith. Although, I am not 100% sure I had the exact same grains in Beer Smith as I actually used. Anyway, what I am trying to figure out is why I was so low on mt bre-boil O.G. I was able to add 2 lbs. of DME and that brought my post boil O.G. up to 15 brix, or 1.061. So I was able to save the brew but does anyone have any ideas on what I did wrong? Thanks for any advise.

 

[freisste]

First of all, make sure you are figuring out the right thing. You can't get an efficient from just OG. For example, an OG of 1.050 with a volume of 6 gallons is considerably more sugar than an OG of 1.060 with only 3 gallons. So if your "issue" is too much sparging or not enough boil off, your mash efficiency may not be the issue.

Now that we for that out of the way.

Ways to increase efficiency:
-stir more
-finer crush
-more sparging
-good temperature control (?)

Also, make sure you have completed the mash by confirming with an iodine test. Confirm your thermometer is accurate as well.

 

[fartinmartin]

You clearly had a very ineffective mash, to get a reading of only 5brix is indeed terrible! get your mash liquor stable at 71C then add the malt this gives me a mash at 63C, my mash tun is very crudely insulated and needs to be stirred every 15 mins or so or I would get very cold spots.
I hope you have checked your equipment, hydrometer gives 1.000 in water at the right temp, and that your refractometer has been calibrated.

 

[fartinmartin]

Doubled

 

[helibrewer]

You need to analyze this at two places; 1) Conversion efficiency (in the MLT), and 2) Lautering efficiency for getting the sugar into the kettle.

www.braukaiser.com has an excellent article for going through this process.

Your Conversion Efficiency should be in the 90+% range. Braukaiser has a nice chart that indicates what your First Wort gravity should be based on your grain:water ratio.

He also provides a nice chart and procedure to calculate how much sugar you leave behind after sparging. This loss is subtracted from the Mash Efficiency determined above. The overall number should still be in the 90+% range.

The total Brewhouse efficiency takes into account such things as volume loss during transfers, dead space in vessels, boil off, etc. and usually results in an efficiency in the high 70's to mid 80's which is the number you see most brewers reference.

So you first have to determine whether you are getting everything out of the grain that you can. Then determine if you are getting everything out of the MLT and into the kettle that you can. Once you know those two things, adjustments are easy and logical.