Mesh baskets - squeeze and sparge?

[pretzelb]

I have a Co Brewing nano with a solid sided mesh basket for the mash. For the most part I have been doing a type of squeeze where I push down with a spare lid after my full volume mash. I'm getting annoyed with this method because I'm starting to see a variance with each batch. In an effort to be more consistent I'm debating holding back a gallon or two from the full volume mash and then doing a simple pour over without any squeeze. My assumption is this will lead to more consistent results which is my goal.

Any words of wisdom on squeezing vs sparging vs both vs neither?

 

[Kerrbrewer]

I had the most consistent results with drain, squeeze, dunk sparge and squeeze again.

 

[Horseflesh]

There is another option: if squeezing causes too much variation for your liking, don't squeeze at all. Maybe sparge with a gallon pour-over, let it drip for a fixed amount of time, and that's it. You'd leave some wort behind, but it might not matter if it helped consistency.

 

[Nmnbrewer]

Full volume, drain, squeeze down with a pan lid is my routine. Results seem pretty consistent.

 

[doug293cz]

I have a Co Brewing nano with a solid sided mesh basket for the mash. For the most part I have been doing a type of squeeze where I push down with a spare lid after my full volume mash. I'm getting annoyed with this method because I'm starting to see a variance with each batch. In an effort to be more consistent I'm debating holding back a gallon or two from the full volume mash and then doing a simple pour over without any squeeze. My assumption is this will lead to more consistent results which is my goal.

Any words of wisdom on squeezing vs sparging vs both vs neither?

You need to know whether the inconsistency is due to variations in lauter efficiency or conversion efficiency, as both affect mash and brewhouse efficiency. You can measure and track your conversion efficiency using the method here. Lauter efficiency is calculated by dividing mash efficiency by conversion efficiency. Lauter efficiency naturally decreases with increasing grain bill weight. If you have varying grain bill sizes, this may be part of your inconsistency.

Grain absorption rate has a significant affect on lauter efficiency, and degree of squeezing affects grain absorption rate. If you can't squeeze consistently, you will have variations in lauter efficiency.

A pour over sparge will increase your lauter efficiency, but is an inherently difficult to control precisely, and can give you variability.

The easiest sparge process with which to get consistent results is batch (or dunk) sparging.

Brew on

 

[Seattle2k]

Sometimes I sparge, but often I just squeeze as much out as i can, until my hands can't stand the heat. Somehow, I keep hitting my gravity numbers.

 

[pretzelb]

You need to know whether the inconsistency is due to variations in lauter efficiency or conversion efficiency, as both affect mash and brewhouse efficiency. You can measure and track your conversion efficiency using the method here. Lauter efficiency is calculated by dividing mash efficiency by conversion efficiency. Lauter efficiency naturally decreases with increasing grain bill weight. If you have varying grain bill sizes, this may be part of your inconsistency.

Grain absorption rate has a significant affect on lauter efficiency, and degree of squeezing affects grain absorption rate. If you can't squeeze consistently, you will have variations in lauter efficiency.

A pour over sparge will increase your lauter efficiency, but is an inherently difficult to control precisely, and can give you variability.

The easiest sparge process with which to get consistent results is batch (or dunk) sparging.

Brew on

With my single vessel system I not able to perform what I think you mean by batch or dunk sparging. Also I am not sure what that would mean when it comes to a lauter. If I just squeeze would that be considered a lauter step? Or would it require at least a pour over sparge step?

Regarding the link, I'm not sure I understand the "eGrain" value. I have been doing a basic mash efficiency calculation where I total the max PPG for each recipe and then determine how close I get to that value. I think eGrain is 80% of the max PPG but I'm not sure.

 

[doug293cz]

With my single vessel system I not able to perform what I think you mean by batch or dunk sparging. Also I am not sure what that would mean when it comes to a lauter. If I just squeeze would that be considered a lauter step? Or would it require at least a pour over sparge step?

Regarding the link, I'm not sure I understand the "eGrain" value. I have been doing a basic mash efficiency calculation where I total the max PPG for each recipe and then determine how close I get to that value. I think eGrain is 80% of the max PPG but I'm not sure.

Lautering is just separating the sugar (and the wort in which it is dissolved) from the spent grain. This can be done be leaving the grain in place and draining the wort to another vessel (traditional MLT), or leaving the wort in place and removing the spent grain (BIAB and similar.) Lautering doesn't require a sparge, but a sparge allows more of the sugar to be separated from the spent grain, so it improves lauter and mash efficiency. Lauter efficiency is just the quantitative measure of how well you separated the sugar from the grain. Since squeezing is part of the process of separating sugar from the grain, it is a lauter step.

eGrain is the percentage of the weight of the grain that can be converted to "extract." Extract is all the soluble material that results from the mashing process. It is mostly sugar, but also contains proteins and many other compounds. Sucrose, which is 100% soluble has 46.17 pts/lb. To determine points per pound for grains, you multiply eGrain times 46.17. So, an eGrain of 80% corresponds to 80% * 46.17 = 36.9 pts/lb. Likewise you can convert pts/lb to eGrain (wt% potential extract) by dividing pts/lb by 46.17.

You need to be careful with Braukaiser's formulas. The way they are written, they are only valid for volumes in liters, and weights in kilograms. And if he were really rigorous, he would use weight of water rather than volume of water, since 1 liter only weighs 1 kilogram at 4°C.

Most people don't need the formulas, they just need to use the table of mash thickness vs. max mash wort SG and divide their actual mash wort SG by the max in order to get their conversion efficiency.

Brew on

 

[pretzelb]

Well, I'm brewing right now and noticed more poor readings from my mash. I decided to extend from a 60 minute mash to 90 minutes and take some more readings to see if I could find an issue. At the 90 minute mark pulled a sample and then hoisted the basket to drain. Before taking a reading after the basket drained I decided to grab some distilled water and check the refractometer. Bingo. It was way out of whack. I adjusted it and readings seem more normal now. Going to have to keep collecting data to see if that was the main issue.

 

[pretzelb]

Lautering is just separating the sugar (and the wort in which it is dissolved) from the spent grain. This can be done be leaving the grain in place and draining the wort to another vessel (traditional MLT), or leaving the wort in place and removing the spent grain (BIAB and similar.) Lautering doesn't require a sparge, but a sparge allows more of the sugar to be separated from the spent grain, so it improves lauter and mash efficiency. Lauter efficiency is just the quantitative measure of how well you separated the sugar from the grain. Since squeezing is part of the process of separating sugar from the grain, it is a lauter step.

eGrain is the percentage of the weight of the grain that can be converted to "extract." Extract is all the soluble material that results from the mashing process. It is mostly sugar, but also contains proteins and many other compounds. Sucrose, which is 100% soluble has 46.17 pts/lb. To determine points per pound for grains, you multiply eGrain times 46.17. So, an eGrain of 80% corresponds to 80% * 46.17 = 36.9 pts/lb. Likewise you can convert pts/lb to eGrain (wt% potential extract) by dividing pts/lb by 46.17.

You need to be careful with Braukaiser's formulas. The way they are written, they are only valid for volumes in liters, and weights in kilograms. And if he were really rigorous, he would use weight of water rather than volume of water, since 1 liter only weighs 1 kilogram at 4°C.

Most people don't need the formulas, they just need to use the table of mash thickness vs. max mash wort SG and divide their actual mash wort SG by the max in order to get their conversion efficiency.

Brew on

I'm still a bit confused on this so forgive my ignorance.

When it comes between conversion and lauter efficiency, would they be the same thing you just pulled your bag from the single kettle and did NO squeeze? I'm wondering if conversion would be calculated before the bag is moved, and lauter is everything after that (squeeze and sparge).

eGrain still confuses me. From what you've said, it sounds like a constant 36.9. It also sounds similar to what I'm doing to calculate the max PPG. I take the potential SG of each grain type (per Beersmith) and then multiple that by the pounds of grain to get the max points. That value is divided by the full volume in gallons to get the max PPG. I use that max PPG as the baseline - if I were to get 100% of all the possible sugars then that would be used to get the gravity.

 

[doug293cz]

I'm still a bit confused on this so forgive my ignorance.

When it comes between conversion and lauter efficiency, would they be the same thing you just pulled your bag from the single kettle and did NO squeeze? I'm wondering if conversion would be calculated before the bag is moved, and lauter is everything after that (squeeze and sparge).

eGrain still confuses me. From what you've said, it sounds like a constant 36.9. It also sounds similar to what I'm doing to calculate the max PPG. I take the potential SG of each grain type (per Beersmith) and then multiple that by the pounds of grain to get the max points. That value is divided by the full volume in gallons to get the max PPG. I use that max PPG as the baseline - if I were to get 100% of all the possible sugars then that would be used to get the gravity.

In the homebrew world, mashing is considered as the process of turning malted grain into wort in a kettle. There are two steps to this process:

1. Converting the starch in the grain into sugars (saccharification), and
2. Separating the created sugar from the spent grain (lautering)

We define the efficiency of the combined steps as mash efficiency, and more formally as:

Mash Efficiency = Weight of Sugar in BK / Weight of Max Potential Sugar in Grain​

We can also define efficiencies for the two steps of the overall process (i.e. conversion efficiency and lauter efficiency):

Conversion Efficiency = Weight of Sugar Created in Mash / Weight of Max Potential Sugar in Grain
Lauter Efficiency = Weight of Sugar in BK / Weight of Sugar Created in Mash​

So conversion efficiency can be determined before the the wort and grain are separated. Conversion efficiency only measures how much of the available starch was converted to sugar. Lauter efficiency only measures how well you separated the sugar from the spent grain (not affected by how much sugar you created.) Some simple algebra shows that:

Mash Efficiency = Conversion Efficiency * Lauter Efficiency​

When diagnosing low mash efficiency, it's important to know whether your conversion efficiency is low, or your lauter efficiency is low, since the actions required to fix each of those are totally different.

Let's look at an example. Suppose we have 10 lbs of grain with an average extract potential of 80% (or 46.17 * 80% = 36.9 pts/lb.) That means if we convert all of the starch to sugar (100% conversion efficiency) we will have 10 lbs * 80% = 8 lbs of sugar dissolved in the wort in the mash. On the other hand if we only get 85% conversion efficiency, the we only have 10 lbs * 80% * 85% = 6.8 lb of sugar in the mash.

Now let's say we have a lauter process that gets 80% of the created sugar from the mash to the BK. If we've done things correctly, then the wort concentration will be uniform throughout the mash, so 80% of the sugar weight will correspond to 80% of the wort volume. So getting 80% of the sugar out of the mash is the same as getting 80% of the wort out of the mash. In the case of 100% conversion efficiency, the total collected sugar will be 8 lbs * 80% = 6.4 lbs of sugar in the BK. The mash efficiency is then 6.4 lb / 8.0 lb = 80%. In the case of 85% conversion efficiency with 80% lauter efficiency, the total collected sugar will be 6.8 lbs * 80% = 5.44 lbs. The mash efficiency is then 5.44 lb / 8.0 lb = 68%.

If we squeeze more wort out of the spent grain, we get more sugar as well, so the lauter efficiency (and the mash efficiency) go up.

That's a long winded answer to say: yes conversion efficiency is before you pull the bag, and lauter efficiency is what percentage of the sugar created before you pulled the bag is in the collected wort in the BK after you pull the bag and squeeze, sparge, or whatever.

eGrain is just the name of a variable that Braukaiser invented to use in his equations. It is really just the extract potential of the grain in weight percent. So, if the potential of the grain is 80% then that means that 10 lbs of grain can produce a maximum of 8 lbs of sugar. The only constant is the pts/lb for sucrose, which is 46.17 pts/lb. If you put in 1 lb of sugar, you will get 46.17 gravity points. To determine pts/lb for other grains/adjuncts you multiply the potential in wt% times 46.17. Potential in wt% is what is usually reported on malt analysis sheets. Most brewing software converts the potential in wt% into pts/lb in order to make things easier for users.

If you total up pts/lb times lbs for each malt you use and divide by the volume of the wort in the mash, you get the maximum possible SG of the wort in the mash at 100% conversion efficiency. (Max SG ~= 1 + [pts/lb * lbs] / 1000.) The problem is that wort volume does not equal strike water volume. This is because the sugar dissolved in the wort increases the volume. Dividing total pts by strike water volume yields a useless number. It will give you an apparent SG that is higher than actually possible. If you then use that SG to determine conversion efficiency, you will get something lower than your real efficiency.

Brew on

 

[pretzelb]

I was found on the BK wiki an article about troubleshooting efficiency and that article has a link to an Excel sheet with all the calculations. That helped me figure out how to do the calculations. I found it odd it doesn't calculate each part of the formula separately but that's just me. I still find some things odd about the formula or the method.

I'm not sure the 80% rule makes much sense. Most of the grain values I've taken from BS say 1036 is the max potential and that calculates closer to 77.9% instead of 80%. There's a paragraph on how being just a few percentage points off can be an issue so I'm surprised this amount of rounding is left as being "close enough". This might have something to do with a weighted based estimate vs the gravity point based estimate involving PPG. I could update my brew stats to use the formulas from BK but I'm not sure what to use for the various grains since all I have is the potential SG values from BS. I might go ahead an recalculate using the potential SG values from BS and divide those by 46.17 to get each grain percentage but like I said that seems to differ greatly from the 80% rule.

 

[doug293cz]

I was found on the BK wiki an article about troubleshooting efficiency and that article has a link to an Excel sheet with all the calculations. That helped me figure out how to do the calculations. I found it odd it doesn't calculate each part of the formula separately but that's just me. I still find some things odd about the formula or the method.

I'm not sure the 80% rule makes much sense. Most of the grain values I've taken from BS say 1036 is the max potential and that calculates closer to 77.9% instead of 80%. There's a paragraph on how being just a few percentage points off can be an issue so I'm surprised this amount of rounding is left as being "close enough". This might have something to do with a weighted based estimate vs the gravity point based estimate involving PPG. I could update my brew stats to use the formulas from BK but I'm not sure what to use for the various grains since all I have is the potential SG values from BS. I might go ahead an recalculate using the potential SG values from BS and divide those by 46.17 to get each grain percentage but like I said that seems to differ greatly from the 80% rule.

One of the problems i have with using grain potentials in SG form from various databases, is that you don't know if they have been converted to as-is basis from the dry basis. So, should you correct for moisture or not? For example an 80% dry basis (1.0369) works out to 80% * 96% (for 4% moisture) = 76.8% (1.0355). Also, you don't know how well your grain matches the database value. So, unless you have the actual datasheet for your lot of malt, you're just guessing anyway. And, 80% isn't an unreasonable default guess. If you really want to do precise calculations you need actual malt lot data.

Then there's the whole other question of whether or not extract potentials for malts with little, or no, diastatic power are reliable. The info on the congress mash that I have seen does not add enzymes or base grain when analyzing these malts. So, no conversion, in addition to what happened during kilning, can take place, only extraction of the pre-converted sugars. That means it's possible when mashed with adequate diastatic power, the real extract potential could be significantly higher than what the datasheet says.

Brew on