Mash Efficiency

[NorthwestBrewman2013]

Mash efficiency has always been a tough one to get pinned down. I can have a brew that I hit everything perfect and the next brew gets a 5-8 pts decrease in efficiency. No change in the process...just bad luck maybe?

I currently have a 12 gallon keggle system with a mash tun and boil kettle. I just do a batch sparge and will sometimes add a little extra hot water to the batch to top up my volume. Maybe that's where I'm losing it?

 

[johnwpowell]

What numbers are you getting?

 

[NorthwestBrewman2013]

What numbers are you getting?

My most recent was an Amber Ale and IPA.

Amber Ale - OG 1056
Est 1057

IPA - OG 1057
Est 1063

I know it doesn't seem like much but there were honestly no variables or differences in either mash/boil. Ingredients were the only change and I typically use 2-row as my base in all my beers. Same systematic approach every time. What do you think?

 

[Sailingeric]

I think we need more info. How much grains are you using in your recipe and what are the batch sizes? More grains the lower your efficiency will be. Are batch/ fly/ or no sparging??

 

[NorthwestBrewman2013]

I think we need more info. How much grains are you using in your recipe and what are the batch sizes? More grains the lower your efficiency will be. Are batch/ fly/ or no sparging??

Amber Ale - 10 gallon - Batch Sparge

16 - 2row
3 - Crystal 80
1 - Victory

Mash at 152 Degrees. OG 1056 (I was incorrect on my last post, the Estimated should have been 1056 as well).

IPA - 5 gallon - Batch Sparge

8.6 - 2row
2 - Rye
1 - Crystal 40

Mash at 152 Degrees. Est OG - 1063 Actual OG - 1057

 

[johnwpowell]

Testing mash ph?

 

[doug293cz]

The accuracy of your efficiency measurements is strongly dependent on the accuracy of your grain weight, volume, and SG measurements. Do you have error estimates, or accuracy of measurement estimates, for your weight, volume, and SG measurements. If your volumes are off, then your OG's will be off, even if everything else is perfect.

Your estimated OG values look reasonable, but without knowing your actual pre-boil volumes it's hard to say just how accurate they are. Also, how are you dividing up your strike and sparge water volumes?

Brew on

 

[NorthwestBrewman2013]

The accuracy of your efficiency measurements is strongly dependent on the accuracy of your grain weight, volume, and SG measurements. Do you have error estimates, or accuracy of measurement estimates, for your weight, volume, and SG measurements. If your volumes are off, then your OG's will be off, even if everything else is perfect.

Your estimated OG values look reasonable, but without knowing your actual pre-boil volumes it's hard to say just how accurate they are. Also, how are you dividing up your strike and sparge water volumes?

Brew on

You hit on a very good point. I may have misrepresented my mash technique. My usual is to mash thin usually 1.5qt/pound and just drain my mash tun. I'll check the PB Gravity to see if I am close to what I was shooting for. In the case of the Amber Ale in this post I was 100% right on. The IPA I was a little low. So I tried to pull a fast one on the grain and add about 2.5 gallons of hot water to the mash, re-stir, let sit for 20 minutes or so, and drain to add a touch more sugar to my wort.

To honestly answer the question, no, I do not have a crazy specific measurement to my strike water.

I'm thinking that I need to be a little more specific on my strike water and how long I vorlauf. I've noticed that the longer I clarify the wort prior to sending it to the boil kettle, the better my efficiency. Thoughts?

 

[doug293cz]

You hit on a very good point. I may have misrepresented my mash technique. My usual is to mash thin usually 1.5qt/pound and just drain my mash tun. I'll check the PB Gravity to see if I am close to what I was shooting for. In the case of the Amber Ale in this post I was 100% right on. The IPA I was a little low. So I tried to pull a fast one on the grain and add about 2.5 gallons of hot water to the mash, re-stir, let sit for 20 minutes or so, and drain to add a touch more sugar to my wort.

To honestly answer the question, no, I do not have a crazy specific measurement to my strike water.

I'm thinking that I need to be a little more specific on my strike water and how long I vorlauf. I've noticed that the longer I clarify the wort prior to sending it to the boil kettle, the better my efficiency. Thoughts?

Adding the extra sparge water will lower your OG unless you compensated by boiling off the extra volume to hit your original post-boil volume target.

If longer vorlauf is helping your efficiency, then that implies that your conversion is not complete during your chosen mash time. The extended vorlauf just allows more time for more conversion to occur. You can test for conversion completion by measuring the SG of the wort in the mash over time. When the SG stops increasing your mash is done. You can also use the final mash SG to calculate your conversion efficiency using the method here.

Maximum lauter efficiency for batch sparging is obtained when your first runnings volume and sparge runnings volume are equal. However, the efficiency changes over a range of 60:40 (initial:sparge) to 40:60 (initial:sparge) are insignificant (less than measurement error), so you don't have to hit exactly 50:50. A good practice is to use 60% of your total water to mash, and 40% to sparge. The grain absorption will shift your runnings ratio towards 50:50. For the two cases you showed, a 50:50 ratio would have given you mash thicknesses in the 1.6 to 1.75 qt/lb. This is actually a good thing, as thinner mashes convert faster than thicker mashes.

Brew on

 

[Morrey]

Are you grinding your own grains or buying them pre-milled from outside sources?

 

[NorthwestBrewman2013]

Are you grinding your own grains or buying them pre-milled from outside sources?

I grind mine at the LHBS.

 

[Morrey]

I saw swings in efficiency despite trying to replicate my process while I was buying grains already milled. I bought my own mill and slowly got efficiency increases as I dialed in my roller settings. I now hit similar numbers every brew since I grind my own grains with a consistent grind. May be worth a look.

 

[NorthwestBrewman2013]

Adding the extra sparge water will lower your OG unless you compensated by boiling off the extra volume to hit your original post-boil volume target.

If longer vorlauf is helping your efficiency, then that implies that your conversion is not complete during your chosen mash time. The extended vorlauf just allows more time for more conversion to occur. You can test for conversion completion by measuring the SG of the wort in the mash over time. When the SG stops increasing your mash is done. You can also use the final mash SG to calculate your conversion efficiency using the method here.

Maximum lauter efficiency for batch sparging is obtained when your first runnings volume and sparge runnings volume are equal. However, the efficiency changes over a range of 60:40 (initial:sparge) to 40:60 (initial:sparge) are insignificant (less than measurement error), so you don't have to hit exactly 50:50. A good practice is to use 60% of your total water to mash, and 40% to sparge. The grain absorption will shift your runnings ratio towards 50:50. For the two cases you showed, a 50:50 ratio would have given you mash thicknesses in the 1.6 to 1.75 qt/lb. This is actually a good thing, as thinner mashes convert faster than thicker mashes.

Brew on

*Sound of hand hitting forehead*. That first paragraph makes perfect sense. I didn't allow my boil to go long enough to boil off the excess water I added to the mash. I like the idea of a 60/40. I'll have to try that my next few attempts to see if I have any drastic changes in efficiency. I have the equipment, now I just need to get the process down.

 

[doug293cz]

*Sound of hand hitting forehead*. That first paragraph makes perfect sense. I didn't allow my boil to go long enough to boil off the excess water I added to the mash. I like the idea of a 60/40. I'll have to try that my next few attempts to see if I have any drastic changes in efficiency. I have the equipment, now I just need to get the process down.

Based on your numbers, you are already running close to maximum theoretical efficiency. Don't expect to see any drastic changes. My 60:40 rule can just simplify your calculations.

Brew on