Two mashes or reiterated mash?

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Rob2010SS

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Don't want to hijack OP's thread here, but I'm considering a reiterated mash on a big stout. However, everything I've read, I can't find the answers to the questions that I still have...

1. I understand that you're splitting the mash into 2 parts. Are you splitting each grain type evenly so you have identical mashes OR are you doing roasted grains separately?
2. I use a bag in my mash tun during mash. Makes removal of grains easier. To get the most out of the first mash, is it ok to squeeze the bag to get the most volume out of it?
3. pH will be adjusted at the first mash. What about the second mash? Will you not have to worry about mash pH in the second mash because you already adjusted it once for the first one?



In my scenario, the recipe has 49.75 lbs of grain. Would a reiterated mash for me look like this...?
1. Split each grain type evenly into 2 identical mashes with 24.875 lbs of grain each.
2. Add minerals to strike water for water profile and pH adjustment.
3. Dough in on mash #1
4. Towards end of mash #1, raise temp back up to Strike temp for mash #2.
5. Skip sparge on first mash and pull out grain bag and squeeze to get as much volume out.
6. Begin 2nd mash by placing grain bag with new grains in mash tun which still contains wort from first mash.
7. Perform full mash, mashout and sparge as usual to achieve desired pre-boil volume.

Is it really that simple?
 

jerrylotto

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Don't want to hijack OP's thread here, but I'm considering a reiterated mash on a big stout. However, everything I've read, I can't find the answers to the questions that I still have...
Inline:

1. I understand that you're splitting the mash into 2 parts. Are you splitting each grain type evenly so you have identical mashes OR are you doing roasted grains separately?

>1A - splitting evenly by weight but first half is all base and the second half is remaining base + roasted grains.

2. I use a bag in my mash tun during mash. Makes removal of grains easier. To get the most out of the first mash, is it ok to squeeze the bag to get the most volume out of it?

>2A - I use a basket recirculation system so sparge - no squeeze. I guess the answer to your question is a function of your crush and your bag mesh. I see no problem with squeezing a bag as long as what comes out is mash liquor.

3. pH will be adjusted at the first mash. What about the second mash? Will you not have to worry about mash pH in the second mash because you already adjusted it once for the first one?

>3A - this is an important question - your pH will be different on the way out. It needs to be checked and potentially buffered further. I use fresh water sparge for both halves and take the sparge liquor first to make up the strike for batch 2. Once you get the strike volume right (by adding first runnings to the collected sparge from step 1) and mixed in well, check and adjust your pH and take into account that roasted grains will lower the pH more than the base grains.

In my scenario, the recipe has 49.75 lbs of grain. Would a reiterated mash for me look like this...?

> Big batch! I think you can see the difference in our process from the above so I didn't comment on your process but no sparge batch 1 is NOT how I do this.
 
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Brewshna

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1. I split mine evenly this time and that worked for me. Fixed PH on first mash, second won't change it much
2. I didn't use a bag but my all in one lauter basket. I pushed down to get as much as possible with as little as possible sparge.
3.see 1.

Mines fermenting away and seems very happy. The brew day was a bit chaotic but play the rest by heart. Sparged the first until I had 30l, drained 4l for my second sparge. Mashed in second lot for apr. 75 mins and sparged with the Wort until I had 24.5l. Boiled for 60ish min and voila 25P Wort, tasting of chocolate and hops.
 

Rob2010SS

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Inline:



>1A - splitting evenly by weight but first half is all base and the second half is remaining base + roasted grains.
1. I split mine evenly this time and that worked for me. Fixed PH on first mash, second won't change it much
So you guys do it differently. Why add roasted grains to only one vs splitting in both?

Sorry for all the questions. I can't mentally bring myself to do something without knowing the Why's.
 
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Brewshna

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I think both variants are doable. I might try the other Variante next time. Also I have had the idea of mashing twice and storing the first mash in a fermenter while the second is going, hence the threads title.
 

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In Randy Mosher’s book “Radical Brewing” he calls it a “double double”. It says the process is wasteful of time and men, and at times it was illegal.

I’ve only done it once. A long time ago. There was substantial sugar remaining in the grain and efficiency was low. If you have 2 mash tuns, you could make your strong beer and then re-run both mashes again and make a second “normal” beer. Would make for a long brew day though
 
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Wouldn't take that much longer than reiterated mashing. If you pre heat the mash water. And efficiency should be good, as its two normal mashes. Maybe I'll try some day. Here's the eff. of my last brew
 

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I've done several reiterative mashes. Check my posti g history. They are great for attaining high gravity at high efficiency.

The highest gravity I hit was 1.120. The highest gravity I'll do with a non reiterative mash is 1.075. Anything higher than that get double mashed.

The second mash converts very quickly because the enzymes are already active in the mash liquid. Nevertheless, I use long mash times because I always do and it's easy to do on my system.
 
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FG is at 9P at the moment. I don't think it's going to change a lot in another week. So came out a little to high, still tastes very bitter at this point (but that will change a lot while lagering) shook fermenter and hoping for 8P,but don't think it'll get there.
 

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Never heard of anyone adding nibs to the mash before. Did you get anything out of it? I always roast mine too to avoid putting them in vodka.
 
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I roasted them too. Also some roasted going in after fermentation is over. I read about it somewhere and wanted to try it. Will look for the article
 
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Just two I know
 

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I've done several reiterative mashes. Check my posti g history. They are great for attaining high gravity at high efficiency
I get 1.127 - 1.129 pretty reliably from my stout recipe reiterative mash after the (2 hr) boil. I use a total of 7.5 gal of water (3.3 gal water strike 1, 2.0 gal water sparge 1, 3.3 gal runnings for strike 2, 2.2 gal water sparge 2) and each grain bill is about 12#. I also add about 2# DME after the mash and keep the boil vol over 5.5 gal.
 

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Would you share your base recipe?
18# 2-row pale
3# Munich
1# 60L Crystal
1# Chocolate
8 oz Roasted Barley
4 oz Black Patent

1st mash is 12# 2-row, all of the adjunct grains go into the second (iterative) mash.

Dissolve 2# light DME in the collected runnings and start a 120 min boil.

90 min 1.5 oz Nugget
30 min 1.0 oz Williamette
15 min 1.0 oz Williamette

Cool and oxygenate.

Soak 8 oz toasted oak cubes in 16 oz bourbon during the first 18 days while you ferment out on 3 packs Safale S05. Add the bourbon-soaked oak cubes and wait another 10 days before kegging.
 
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By the way, what could cause my beer to turn out with an FG of 9 instead of 8? I know a few reasons and would like to know what you guys think. I calculated FG using @VikeMan excel sheet calculator, thanks again for that.
 

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By the way, what could cause my beer to turn out with an FG of 9 instead of 8? I know a few reasons and would like to know what you guys think. I calculated FG using @VikeMan excel sheet calculator, thanks again for that.
Brewers yeast can metabolize sugars made up of one ( glucose, fructose, galactose ), two ( primarily maltose, lactose and sucrose ) and three ( primarily maltotriose and raffinose ) monosaccharide units. Anything larger than that and they can not metabolize them. Thus, carbohydrate units of of 4, 5 ,6 etc monosaccharide units remain in the beer as unfermentables to provide a sweetness, viscosity and elevated final gravity. Mashing at higher temperatures produces more of these larger carbohydrates due to the high temperature activity of alpha amylase. Beta amylase cleaves disaccharides (maltose) off of the end of a starch chain but is active above 140F and denatures rapidly above 160F whereas alpha amylase breaks starches less discriminately leading to higher order saccharides, is most active above 150F does not denature rapidly until you hit 170F.
 
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Did mash rather high, first at 66C second at 68C. But did take that into account. Dark malts have lots of unfermentable sugars, which I also took into account. 8P should have been realistic. Maybe too little yeast? 3 packs of dry yeast should have been enough though.
 

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Did mash rather high, first at 66C second at 68C. But did take that into account. Dark malts have lots of unfermentable sugars, which I also took into account. 8P should have been realistic. Maybe too little yeast? 3 packs of dry yeast should have been enough though.
Every mash I do is a step mash, iterative or not. Starting around 100F (38C) for an acid rest, I raise the temp slowly pausing for a protein rest at 120F (49C) until I get to 142F (61C) where I stay for at least 30 min (optimum beta-amylase activity) before hitting the sweet spot around 153F (67C) where alpha and beta both thrive. After at least another 30 min, I mash out at 158F (70C) which is optimal alpha-amylase activity temperature, then sparge with 170F (77C) water.
 
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How do you brew big body beers then? This way your using all the available sugar and making the max amount fermentable. Sounds great for lagers, pils etc but on some ipas you want body, especially bigger beers that need some residual sweetness.

II haven't quite understood what the acid rest is for.
 

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Acid rest is primarily to hydrate the grain kernels and allow the mash pH to stabilize. Not of much use with kilned grains because the kilning process breaks down the enzyme phytase which is key to this step. Pretty much gone above 131F (55C). The mash pH is lowered though the production of inositol hexaphosphate aka phytic acid by breaking down beta-glucans and it is a time consuming step (up to an hour for full effect) but it also makes the starches in the kernel more accessible.
 
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