Squeeze the last bit of sweet wort out when batch sparging

[dsaavedra]

I did a quick search to see if this tip was common knowledge but I didn't find anything so I'm sharing!

Last weekend I was draining my Home Depot Rubbermaid 10 gallon mash tun and thinking how I could maximize efficiency by squeezing out as much of the first runnings as possible yet not have to sit there and wait half an hour for gravity to do it for me.

I thought about how BIABers sometimes squeeze their bag with a pot lid and I thought why not do the same with my mash tun? Turns out the lid from my old 5 gallon economy kettle fits PERFECTLY inside my mash tun, like it was made for it. I lowered it to the grain bed and put all my weight on it and out from the ball valve came at least another quart of sweet first runnings that was hiding out in the grain bed! I did the same thing after I batch sparged to get the last little bit of second runnings out too.

Try it, I'm not sure how much of an efficiency boost you will get but its a quick way to get the last bit of wort out of your mash tun without waiting ages for it to drain via gravity.

 

[edsa1984]

Isn't there a reason you're not meant to squeeze the grain? Tannins or something?

 

[eadavis80]

When I do BIAB, I get a better efficiency since I have been squeezing the bag and have noticed no off flavors. Many agree.

 

[DurtyChemist]

Squeezing the bag is very debated in BIAB. As for getting an addtitioal quart of wort I'd just tilt my mash tun to eliminate the dead space or add an extra quart of sparge water. Having to hard press grains just to get a quart of water isn't worth it, isn't a new idea, and isn't going to give you much, if any, of an efficiency boost. After batch sparking there's so little sugar left in my mash tun it's better than press sparking to get a quart.

 

[Homercidal]

Squeezing is an option.

But, I'm not sure it's worth doing, TBH. For the very small amount of efficiency, you may be better off simply adding a small amount of extra grain.

Especially when describing first runnings, where most of the residual sugar is going to be diluted into the sparge water and drained anyway. The extra sugars left in the sparge water is likely to be so diluted as to be negligible in cost.

So, to me, it's not worth the effort.

 

[wilserbrewer]

I have never squeezed the grain in my MT, but I have let it continue to drip into a pitcher for 20-30 minutes and was shocked at the attitudinal wort that drained....almost 2 quarts if I recall correctly of second runnings.

For max efficiency you should do this ever time you drain the run and that would add time to the process and I'm not that patient for 50 cents...

 

[brewbama]

I mash in a bag in a cooler. Though I don't squeeze, I do lift the bag and get a lot of residual wort. I do the same thing after I batch sparge. I get mid 80 efficiency since I started. No Vorlauf, easy cleanup, and great efficiency.

 

[doug293cz]

Squeezing the drained grains reduces the grain absorption, which does increase efficiency. The chart below shows efficiency for both no-sparge and equal runnings batch sparge for grain absorptions from 0.04 gal/lb to 0.12 gal/lb. 0.12 gal/lb is typical for traditional MLT's. If you only want to squeeze one of the runnings, you will get a bigger benefit from squeezing after the first runnings. If you recover equal volumes for each squeeze, the first one has the highest SG wort, so recovers the most additional sugar.



Brew on

 

[C-Rider]

Isn't there a reason you're not meant to squeeze the grain? Tannins or something?

Old Wife's Tale.

 

[akthor]

I agree that I'd just add to the grain bill even a couple extra dollars is worth the added time and effort squeezing or letting it drip for extended period.

 

[dsaavedra]

So most of you guys don't even let the tun drain completely? You just stop when the flow is reduced to a trickle? I've always propped it up on blocks to tilt it and let it drain fully, so just pressing down on the grainbed with a pot lid is a big time saver for me and eliminates the need to tilt the tun. It takes 30 seconds instead of 5+ minutes (more depending on how patient I am) for gravity to do the work.

 

[GHBWNY]

I did a quick search to see if this tip was common knowledge but I didn't find anything so I'm sharing!

Last weekend I was draining my Home Depot Rubbermaid 10 gallon mash tun and thinking how I could maximize efficiency by squeezing out as much of the first runnings as possible yet not have to sit there and wait half an hour for gravity to do it for me.

I thought about how BIABers sometimes squeeze their bag with a pot lid and I thought why not do the same with my mash tun? Turns out the lid from my old 5 gallon economy kettle fits PERFECTLY inside my mash tun, like it was made for it. I lowered it to the grain bed and put all my weight on it and out from the ball valve came at least another quart of sweet first runnings that was hiding out in the grain bed! I did the same thing after I batch sparged to get the last little bit of second runnings out too.

Try it, I'm not sure how much of an efficiency boost you will get but its a quick way to get the last bit of wort out of your mash tun without waiting ages for it to drain via gravity.

From Beer and Wine Journal.com:

"Tannins are extracted from malt during mashing and hops during the boil."

Nowhere in brewing lore is there a credible indication that "squeezing the bag" creates tannins. They are either in there or they aren't long before squeezing the bag. Squeeze on, bro!

 

[augiedoggy]

Isn't there a reason you're not meant to squeeze the grain? Tannins or something?

I have read and been told the same by my local hbs, That extracts more tannins.. Never did a side by side comparison myself though since I recirculate my mash through my rims now to eliminate the advantages of squeezing.

 

[augiedoggy]

Then again, since I had been told the same this about squeezing a teabag vs dunking it the whole tannin extraction theory seemed kind of sound to me.

Some quick research shows squeezing does appear to have negative possible effects
http://byo.com/all-grain-brewing/item/1924-squeezing-grain-bags-mr-wizard

My thoughts are as long as a sparge is being done its a moot point since rinsing is a better way of removing the residual sugars more efficiently.

 

[brewkinger]

I have never squeezed the grain in my MT, but I have let it continue to drip into a pitcher for 20-30 minutes and was shocked at the attitudinal wort that drained....almost 2 quarts if I recall correctly of second runnings.

For max efficiency you should do this ever time you drain the run and that would add time to the process and I'm not that patient for 50 cents...

I have simply always done this when I brew.
I start the boil after sparging and then leave the pitcher to catch the trickle.
After 5 to 10 min or just dump the pitcher into the boil. I usually end up adding around 0.5 to 1 quart.
Never really thought about what it added to my efficiency because the color of that last trickle amount is like a slightly tainted water and didn't figure it had a lot of sugars in it overall.
I'm with doug that the first running would be the best time to bother spending that additional time to squeeze.at all.

 

[brewkinger]

I have never squeezed the grain in my MT, but I have let it continue to drip into a pitcher for 20-30 minutes and was shocked at the attitudinal wort that drained....almost 2 quarts if I recall correctly of second runnings.

For max efficiency you should do this ever time you drain the run and that would add time to the process and I'm not that patient for 50 cents...

I have simply always done this when I brew.
I start the boil after sparging and then leave the pitcher to catch the trickle.
After 5 to 10 min or just dump the pitcher into the boil. I usually end up adding around 0.5 to 1 quart.
Never really thought about what it added to my efficiency because the color of that last trickle amount is like a slightly tainted water and didn't figure it had a lot of sugars in it overall.
I'm with doug that the first running would be the best time to bother spending that additional time to squeeze at all.

 

[doug293cz]

I have read and been told the same by my local hbs, That extracts more tannins.. Never did a side by side comparison myself though since I recirculate my mash through my rims now to eliminate the advantages of squeezing.

Then again, since I had been told the same this about squeezing a teabag vs dunking it the whole tannin extraction theory seemed kind of sound to me.

Some quick research shows squeezing does appear to have negative possible effects
http://byo.com/all-grain-brewing/item/1924-squeezing-grain-bags-mr-wizard

My thoughts are as long as a sparge is being done its a moot point since rinsing is a better way of removing the residual sugars more efficiently.

Some commercial breweries use mechanical presses to extract the maximum amount of wort from the mash (example.) These presses can squeeze much harder than we possibly can. They would not be using presses if squeezing extracted tannins. Tannin extraction is a chemical process, not a mechanical process. I do not consider BYO an authoritative source on brewing science. I have seen many of the common "old wives tales" of brewing repeated there.

Recirculation does not eliminate the efficiency gains achieved by squeezing. Recirculation may increase your conversion efficiency (mash efficiency equals conversion efficiency times lauter efficiency), but only if your conversion efficiency is less than 98 - 100%. Recirculation improves conversion rate the same way that stirring does. Recirc can allow you to create more sugar in the mash, but it can't allow you to extract a higher percentage of the sugar created.

Squeezing does allow you to extract a higher percentage of the sugar created in the mash (by extracting more of the wort), thus improving lauter efficiency. Squeezing in conjunction with sparging will give you higher lauter efficiency than equivalent sparging alone. See the chart in post #8 above. Lower grain absorption corresponds to more aggressive squeezing (less wort left in the mash.) Squeezing improves the lauter efficiency for both no sparge and batch sparge processes.

Brew on

 

[kh54s10]

Why does it take so long you to drain the tun. It takes me less than 15 minutes. I drain to a trickle, sparge, drain to a trickle again. By this time of the sparge, the gravity of the wort coming out is very low so any more is not going to change my efficiency. If anything it will be so low in gravity that it will make my efficiency worse.

I have never bothered with collecting every bit of the wort still dribbling. I think it is a waste of time.

I also don't think that squeezing has much of an effect on the final product. Current opinion seems that tannin extraction is more due to temperature and pH, a combination that you are unlikely to meet in a homebrewing setting. At least to make any serious detrimental levels.

 

[augiedoggy]

Some commercial breweries use mechanical presses to extract the maximum amount of wort from the mash (example.) These presses can squeeze much harder than we possibly can. They would not be using presses if squeezing extracted tannins. Tannin extraction is a chemical process, not a mechanical process. I do not consider BYO an authoritative source on brewing science. I have seen many of the common "old wives tales" of brewing repeated there.

Recirculation does not eliminate the efficiency gains achieved by squeezing. Recirculation may increase your conversion efficiency (mash efficiency equals conversion efficiency times lauter efficiency), but only if your conversion efficiency is less than 98 - 100%. Recirculation improves conversion rate the same way that stirring does. Recirc can allow you to create more sugar in the mash, but it can't allow you to extract a higher percentage of the sugar created.

Squeezing does allow you to extract a higher percentage of the sugar created in the mash (by extracting more of the wort), thus improving lauter efficiency. Squeezing in conjunction with sparging will give you higher lauter efficiency than equivalent sparging alone. See the chart in post #8 above. Lower grain absorption corresponds to more aggressive squeezing (less wort left in the mash.) Squeezing improves the lauter efficiency for both no sparge and batch sparge processes.

Brew on

I had read about the tannin extraction being a chemical process due to ph when reading up yesterday.
The BYO article doesnt make claims about the tannin extractions but rather the other effects like the solids/proteins which are released having negative effects... I see youre point aboput a commerial brewery but thier process varies a lot from homebrewing with equipment and systems that just arent there or as effective in homebrewing. I dont know how fair it is to say just because some of them do it that it can have no ill effects in homebrewing. Not to mention cost is the main concern of a commercial brewery not necessarily the quality of the product.

I disagree on the recirculation not helping because I believe it assists in flushing the sugars from the crushed grain and dissolving them into the wort the same way many coffee makers uses hot water to extract the coffee without agitation of the beans, only more so since its not just one pass but rather constant recirculation and flow through and around to disolve these sugars and flavors.. My thoughts are this Enables the final sparge rinse to be more effective.
I just think its possible all the suggestions and "Wives tales" in this case might have some basis behind it even if it isnt tannin extraction. for one thing whats the point of a vorlouf if your going to mess up the grainbed and add all those cloudy proteins at the end? protiens which can be more likely to burn to the bottom of the kettle or heating element and effect beer flavor and color.

 

[doug293cz]

I had read about the tannin extraction being a chemical process due to ph when reading up yesterday.
The BYO article doesnt make claims about the tannin extractions but rather the other effects like the solids/proteins which are released having negative effects... I see youre point aboput a commerial brewery but thier process varies a lot from homebrewing with equipment and systems that just arent there or as effective in homebrewing. I dont know how fair it is to say just because some of them do it that it can have no ill effects in homebrewing. Not to mention cost is the main concern of a commercial brewery not necessarily the quality of the product.

I disagree on the recirculation not helping because I believe it assists in flushing the sugars from the crushed grain and dissolving them into the wort the same way many coffee makers uses hot water to extract the coffee without agitation of the beans, only more so since its not just one pass but rather constant recirculation and flow through and around to disolve these sugars and flavors.. My thoughts are this Enables the final sparge rinse to be more effective.
I just think its possible all the suggestions and "Wives tales" in this case might have some basis behind it even if it isnt tannin extraction. for one thing whats the point of a vorlouf if your going to mess up the grainbed and add all those cloudy proteins at the end? protiens which can be more likely to burn to the bottom of the kettle or heating element and effect beer flavor and color.

BYO speculates that additional mash particulates carried thru to the boil might have detrimental effects on the beer. They offer no evidence or rationale for why this might be the case. For anything dissolved in the wort, squeezing will not increase the percentage of any of the dissolved components in the wort (squeezing does not cause more of anything to dissolve.) The Brulosophy trub experiments found that beers made with large amounts of trub were indistinguishable from those made with minimal amounts of trub. (ref 1, ref 2.) Personally, I have won a competition with a beer that started with extremely cloudy wort (due to squeezing.) I think the evidence that does exists, points to trub not being an issue. I will aways give more weight to actual data than speculation.

I agree, the vorlauf would be negated by squeezing, so if you are going to squeeze, then vorlaufing might be a waste of time. I have not found any problem with scorching of cloudy wort using a gas burner. With an electric element, scorching can be an issue if particulates are allowed to settle onto the element. Stirring or recirculation can be used to prevent/minimize settling.

Recirculation does not dissolve more sugar, as all sugar is in solution as it is created. There is never any solid sugar that needs to be dissolved. Recirculation (and stirring) can help to get the gelatinized starch away from the surface of the grits so that the starch can be converted faster, and water can more easily get to the interior of the grits to speed up additional gelatinization, which also speeds up the overall conversion process. If you start lautering before conversion is complete, then recirculation can get you more additional conversion during the lauter process than not recirculating, and this can improve your mash efficiency. But the efficiency increase is due to increased conversion efficiency, not improved lauter efficiency.

To get the best lauter efficiency, the concentration of sugar throughout the mash needs to be uniform. The required uniformity can be achieved with stirring, recirculation, or just waiting long enough for diffusion to reach equilibrium. Once you have uniform sugar concentration, additional agitation or time will not provide any increase in lauter efficiency.

Brew on

 

[helibrewer]

In addition, the grain is milled much finer for commercial mash filters since there is no concern for stuck sparges. The grind is usually 20% or more flour.