Lowering efficiency to avoid over sparging

[Young953]

My system gets 80% efficiency every time, and I feel I have things pretty well dialed, but I know on lighter styles I am pushing the gravity towards the bottom end when it comes to the end of sparge. I am keeping my water ph below 6 to help avoid any tannin extraction, but I can't help but think, should I not be going that low? The only reason I'm thinking about this is I do get a slight drying on the tongue from a recent blonde ale I did. Should I lower my efficiency to ultimately give me more grain=hitting my preboil gravity sooner=less sparging, or am I thinking about this the wrong way?

Any insight is appreciated.

 

[Schreiner]

I do my water calcs with brewers friend, and the default it uses for sparge water PH is 5.4.

I would say you are on the right track, but maybe try to acidify your sparge water with the goal of maintaining a your main mash PH.

 

[Smellyglove]

How do you keep your water pH below 6? By calcium additions? Might caSo4 be the reason it feels dry?

If not, if you have the space in your MT you can try a no sparge for the lighter ones, or just try to mash with a higher water/grain ratio, which will give you less sparge water, which will drop your efficiency a tad.

The easiest would be to acidify your water if you're not doing that already.

 

[Young953]

I do my water calcs with brewers friend, and the default it uses for sparge water PH is 5.4.

I would say you are on the right track, but maybe try to acidify your sparge water with the goal of maintaining a your main mash PH.

This batch was brewed with RO so my final runnings are close to mash ph so I don't believe it's that. It's more of my final runnings being below 1.008

 

[Young953]

How do you keep your water pH below 6? By calcium additions? Might caSo4 be the reason it feels dry?

If not, if you have the space in your MT you can try a no sparge for the lighter ones, or just try to mash with a higher water/grain ratio, which will give you less sparge water, which will drop your efficiency a tad.

The easiest would be to acidify your water if you're not doing that already.

In the mash, it is very bare amount of minerals to RO water, with a light addition of lactic to get to mash ph. Sparge is not modified due to my final runnings being close to mash ph so no need to acidity.
This batch was brewed at a 2.0 ratio to minimize sparging

 

[Smellyglove]

It's the pH which decides how "easily" you'll extract tannins. But what is your mash pH, you just say that the final runnings are close to mash pH. since you use acid, will that say that you maybe targeted 5.2-5.4? and last runnings are still within that range?

 

[Young953]

It's the pH which decides how "easily" you'll extract tannins. But what is your mash pH, you just say that the final runnings are close to mash pH. since you use acid, will that say that you maybe targeted 5.2-5.4? and last runnings are still within that range?

Mash ph was 5.3, final runnings were 5.45.

 

[Smellyglove]

Mash ph was 5.3, final runnings were 5.45.

then your pH is within limits to avoid excess tannin extraction. But you're low with 1.008. I'd say you'd want to sparge less.

But drying feeling and tannins can be different, although the sensation is more or less the same. Tannins are like chewing on a seed you find in grapes, it has a bitterness to it as well as being try. Straight dryness can be from water.

You can try to do a no sparge, and if your mash-tun can't fit all the volume, top up at the boil, this will give you an even lower efficiency. Just so you can test the extremes, and see if that helps. But still. 80% extract efficiency should not by default give you tannins, unless you sparge a lot, and keep your mash pH in place. If your sparge water is over 60% comparing to your mash water, then you're tapping into, or have exceeded (depending on water) the limit for tannin extraction, in light beers, from my experiences.

 

[ba-brewer]

Add more grain would change your efficiency and so would lowering your heat or boil off rate so you don't need to collect so much pre-boil wort.

I just read somewhere that if you crush too fine then can cause increased tannin extraction. A course crush may also help lower your efficiency.


edit:actually lowering your boil off might increase your efficiency but you would have a higher final running.

 

[Smellyglove]

He would need to do both, which is a viable option. Lower boiloff would mean a higher Preboil SG.

 

[Young953]

He would need to do both, which is a viable option. Lower boiloff would mean a higher Preboil SG.

I think I may try to lower my boil off rate a tad to see if the higher preboil gravity will help. After thinking, I don't want to adjust my efficiency because it'll throw my bigger beers off where this isn't an issue, so between lowering my boil off rate slightly and topping off with water if needed, I think that'll do it

 

[brick_haus]

If you want a higher FG and insist on the same yeast, Try increasing your mash temp.

 

[doug293cz]

Add more grain would change your efficiency and so would lowering your heat or boil off rate so you don't need to collect so much pre-boil wort.

I just read somewhere that if you crush too fine then can cause increased tannin extraction. A course crush may also help lower your efficiency.


edit:actually lowering your boil off might increase your efficiency but you would have a higher final running.

Small increases in grain bill won't affect efficiency much, but large increases in grain have a significant negative impact on efficiency, specifically lauter efficiency. Boil off has zero effect on efficiency, although it does affect SG. Fine crush does not increase tannin extraction. That is a myth. Shredding husks doesn't really increase their surface area much, since they are very thin to start with, and tannin extraction is primarily a high pH problem.

Coarse crush can definitely affect your conversion efficiency, as larger grits take longer to gelatinize than smaller grits. Starch can't be converted to sugar until it is gelatinized.

Brew on

 

[ba-brewer]

Small increases in grain bill won't affect efficiency much, but large increases in grain have a significant negative impact on efficiency, specifically lauter efficiency. Boil off has zero effect on efficiency, although it does affect SG. Fine crush does not increase tannin extraction. That is a myth. Shredding husks doesn't really increase their surface area much, since they are very thin to start with, and tannin extraction is primarily a high pH problem.

Coarse crush can definitely affect your conversion efficiency, as larger grits take longer to gelatinize than smaller grits. Starch can't be converted to sugar until it is gelatinized.

Brew on

wow 0 for 4. oops. I am going to have to try and remember where I read the crush thing.

The lower boil off should increase the final run off a bit do I get partial credit for that one.

So if you wanted to lower your efficiency what are the options? You said coarse crush could possible helps some, how about a shorter mash at lower temp before complete conversion or a quicker/faster sparge?

 

[doug293cz]

wow 0 for 4. oops. I am going to have to try and remember where I read the crush thing.

The lower boil off should increase the final run off a bit do I get partial credit for that one.

So if you wanted to lower your efficiency what are the options? You said coarse crush could possible helps some, how about a shorter mash at lower temp before complete conversion or a quicker/faster sparge?

I score you at 2 for 3. You are correct that coarser crush can lower efficiency, specifically conversion efficiency.

If you are having over sparge issues with low gravity beers, the simplest thing to do is go to a no sparge process. Without a sparge, you cannot get excessively low SG on your runnings. Also, a batch sparge is less susceptible to over sparging than a fly sparge.

You are correct that reducing the boil off, in order to get a lower pre-boil volume will reduce the efficiency, and raise the final runnings gravity. It is the lower pre-boil volume that results in lower efficiency (for the same sparge process.) Once you have collected your pre-boil wort, efficiency is unaffected by how much you boil off. A subtle point. I think you were trying to get to the lower pre-boil volume effect in your post, but it wasn't clear on first reading.

Brew on

 

[RM-MN]

Over-sparging should only occur with fly sparging as you continuously add water to trickle down through the mash to extract as much sugar as possible which also raises the pH. Over-sparging shouldn't occur at all with a batch sparge, even a double batch sparge shouldn't raise the pH too much.

It takes high temperature and high pH to extract tannins. Do a batch sparge with cool water. The grain bed will be hot and saturated with water so adding cool water will not make it cold but will limit what tannins can be extracted.

 

[Schreiner]

Over-sparging should only occur with fly sparging as you continuously add water to trickle down through the mash to extract as much sugar as possible which also raises the pH. Over-sparging shouldn't occur at all with a batch sparge, even a double batch sparge shouldn't raise the pH too much.

It takes high temperature and high pH to extract tannins. Do a batch sparge with cool water. The grain bed will be hot and saturated with water so adding cool water will not make it cold but will limit what tannins can be extracted.

You are going to have to heat that water up one way or the other, so if your burner and kettle are sitting idle while you are mashing, why not heat the sparge water to 170? Dial up your favorite water calculator and estimate how much acid to add to drop your sparge water PH to 5.4.

If you do as stated above, you don't have to worry about your running's gravity getting too low. Collect the volume you need based off your boil off rate, and carry on.

 

[doug293cz]

Over-sparging should only occur with fly sparging as you continuously add water to trickle down through the mash to extract as much sugar as possible which also raises the pH. Over-sparging shouldn't occur at all with a batch sparge, even a double batch sparge shouldn't raise the pH too much.

It takes high temperature and high pH to extract tannins. Do a batch sparge with cool water. The grain bed will be hot and saturated with water so adding cool water will not make it cold but will limit what tannins can be extracted.

It is possible to over sparge with a double batch sparge on lower gravity beers. If we assume over sparge is a final runnings SG of 1.010 or lower, then for a 6.5 gal pre-boil volume, and 100% conversion efficiency, you will over sparge if your grain bill is less than 6.95 lb (corresponding pre-boil SG is 1.036. If you only have 90% conversion efficiency, then you over sparge with a grain bill of less than 7.45 lb (corresponding pre-boil SG is 1.034 - 1.035.) For triple batch sparging it is obviously easier to over sparge with larger grain bills than above. For single batch sparging at 90% conversion efficiency, your grain bill would have to be less than 5.6 lb (corresponding pre-boil SG is 1.026, a lite session beer. ) So, almost impossible to over sparge with a single batch sparge.

Brew on