Efficiency and volume question

[MFigz]

I've recently added a a grain mill to my equipment and I just brewed my first batch using it. Everything went smoothly, but I got some numbers that I was not expecting and I don't exactly know why or how to adjust beersmith to account for it in the future.

My target boil volume/gravity was 8.5gal/1.037, but I hit 1.010 in my run off at 7.6gal and my gravity was already 1.044.

Since this was a test batch to dial in my efficiencies I just rolled with it rather than adding top off water to match boil volume or gravity, but if I were to add water to reach 1.037 I would have had a 9gal boil volume.

I feel like I should understand this already but I'm a bit confused as to what caused it and how to account for it in the future? The thing that is really getting me is the 1.010 run off gravity. I've never come close to that in the past before hitting my boil volume. I obviously had higher mash efficiency then I typically get from LHBS mill, but I can't adjust the mash efficiency field in beersmith and when I adjust the Brewhouse efficiency to match my measured efficiency it didn't effect much with the target volumes and gravity.

Thanks for any insight!
Mike

 

[IslandLizard]

Milling your own vs. a store mill will pretty much always get you higher efficiency. That's what you observed, and correctly diagnosed. Wait until you optimize your milling to your system... 80% is only the beginning.

Only Brewhouse Efficiency is editable in BS, but it will accomplish the same. Mash efficiency is calculated back from BH efficiency together with a few other parameters you've entered.

http://www.beersmith.com/forum/index.php?topic=6555.0

You could calculate your mash efficiency from your actual gravities and volumes, and divide by the theoretical extraction potential of the grist.

 

[SoCal-Doug]

Had you continued to sparge beyond the 7.6 gallons to your preboil target volume, your preboil gravity would have continued to lower toward your target of 1.037. The runnings get thinner as sparging continues, thus making your overall boil kettle gravity lower. Would it have hit exactly? Maybe or maybe not.

An end runnings target of 1.010 is fine but its not a "hard" target. It's ok to drop a few points below that and its generally accepted that you want to be at that or less. Don't use the runnings as a "stop sparging" guide. Use it as an indication of how efficient your sparging is. Go for your target preboil volume, then adjust your recipe and volumes on the next batch based on your gravity over/under in the previous batch. When your preboil volume is reached, then measure the end runnings before shutting off the valve.

There are basically three efficiency ratings. Beersmith does not break them all out but you can do your own spreadsheet or calculations if you want to know all three.

1. Mash efficiency: How well did you do at converting the starches to sugars. Based on the volume of water in the mash versus the amount of each grain and what each grain used is capable of delivering in a typical environment. A gravity reading is taken at the end of the mash before sparging starts, then mash efficiency is calculated. To be super OCD accurate, you can look up each grain's specific yield and potential, but a guestimate average is fine also.

2. Lauter (sparge) efficiency: How well did you rinse the grains and get the goodness out of the grains and into your boil kettle. Based on the preboil volume and it's gravity. If you sparge too quickly or stop sparging too soon, this efficiency can drop. For this to be the most accurate, your preboil volume should be accurately achieved, or the calculation changed to reflect actual volume rather than target.

3. Brewhouse efficiency: The whole thing. Based on how close your preboil volume, postboil volume, and OG versus the targets, you were. To achieve maximum BH efficiency, mash well, lauter well, nail your volume targets. Sometimes adjusting boil flame or intensity may be needed or if you overshoot your post boil volume, simply add a bit of water.

All of these numbers tell us how to adjust our future processes. As you do more batches, you will zero in on the results and processes as your efficiency ratings go higher. Hope this all makes sense and helps a bit.

 

[MFigz]

Thanks a lot! It all makes sense but I've always heard that if you sparge below 1.010 you risk extracting tannins. It sounds like you are saying it's ok? I mean .. Even if I extract tannins in the last 3/4 gallons, will it effect overall flavor in a noticeable way?

Appreciate the help on this one!
Mike

 

[SoCal-Doug]

Extracting tannins is more a function of pH going above 6.0 and/or the sparge water temp going above 180F. In theory, as you rinse the grains, the pH buffering capability is being washed away also. That's why the runnings pH will rise throughout the sparge (your mash might start around 5.4 but as you drain it while rinsing with water that is closer to 7.0, the runnings pH rises). My typical sparge ends at about 1.005 with a pH of around 5.8 to 5.9. For a typical 5 gallon batch, I shoot for a total sparge time of at least 30 minutes. Just a slow trickle, and the grains always fully submerged. When the sparge is done, the grain looks grey, dead, lifeless and spent.

If you were to sparge with 200F water through to a pH of 6.5, your beer would probably taste like you are sucking on a teabag or sipping a cheap merlot

 

[MFigz]

Lol I love a good merlot. I've been considering buying a pH meter soon are the $20 ones I see on Amazon worth it, or do I need to drop some real cash for a expensive one? The strips do nothing for me I'm color blind and can't decifer them very well.

 

[SoCal-Doug]

pH strips are totally useless. Most of them are yellow to brown color coded identically to pale ale, amber, porter and stout

If you are going to invest in a pH meter, I recommend you drop a little more cash. Just like having a good refractometer that will last a lifetime. You can find Milwaukee's with temp correction for just over a hundred that are really good. You don't need the $500 laboratory versions. Keep the probe in real storage solution and calibrate it often. You'll be much happier.

 

[RM-MN]

Thanks a lot! It all makes sense but I've always heard that if you sparge below 1.010 you risk extracting tannins. It sounds like you are saying it's ok? I mean .. Even if I extract tannins in the last 3/4 gallons, will it effect overall flavor in a noticeable way?

Appreciate the help on this one!
Mike

There are 2 factors necessary for tannin extraction, pH which you control by the amount you sparge while checking the gravity of the runnings as you have been doing, and temperature. As long as you keep the temperature lower than about 170, you should extract very little tanning and that is easy to do if you use cool water for the sparge. It makes little difference in the efficiency of the sparge whether you use hot or cool water and cool water doesn't require another kettle to heat it. A plastic bucket works fine.