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Acid Rest

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Piotr

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I don't think there are any. Only the weizen beer can benefit from a rest in low temperaure (40-44C), I call this ferulic rest, but some call it (incorrectly) acid rest
 

ClaudiusB

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I have heard that some malts work better when an acid rest is performed. Which malts, if any, would require this?
I mash in at the acid rest temp (95°-98°F) for two reasons.
1. To adjust mash pH with Phosphoric acid to the required value without
rushing.
Very little conversion takes place.
I don't depend on the Phytase enzymes to lower the pH, it can take
several hours to lower the mash pH.
2. Enzyme preparation, prepares the enzymes for the hard work ahead.
Resting the mash at this temp for 30 min. improves yield regardless of base
malts used.

I don't think there are any. Only the weizen beer can benefit from a rest in low temperaure (40-44C), I call this ferulic rest, but some call it (incorrectly) acid rest
Ferulic acid rest is different than the acid rest (temp is different).
The ferulic acid brings out more of the phenolic character (clove) of Weizenbiers during fermentation by converting it to 4VG.

The temp I use is around 113°F.

Cheers,
ClaudiusB
 

mux

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I was thinking of this, I did a RIS and I think that my pH was off due to the dark malts. I think if I mash in at 115- 120 and adjust the pH I will be able to fix it before any enzymatic conversion takes place. Any one else do this?
 

mjohnson

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My understanding is that when pH is off due to dark malts, its usually means the mash is too acidic (low pH). If you suspect this is what is happening to your RIS, then an acid rest would be attempting to lower it further - which might not be what you want.

I'm no expert, though. I just play one on the internet.
 

Newbeerguy

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I was thinking of this, I did a RIS and I think that my pH was off due to the dark malts. I think if I mash in at 115- 120 and adjust the pH I will be able to fix it before any enzymatic conversion takes place. Any one else do this?
115-120 maybe a tad too hot for the acid rest. Actually some protien rests are conducted at 122. I use 97-100 degrees for my acid rests.
 

erikpete18

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My understanding is that when pH is off due to dark malts, its usually means the mash is too acidic (low pH). If you suspect this is what is happening to your RIS, then an acid rest would be attempting to lower it further - which might not be what you want.

I'm no expert, though. I just play one on the internet.
I thought this was the case as well, that the acid rest was more to lower the pH into a good range due to higher alkalinity levels in water. If you're trying to raise the pH in your RIS mash, you can toss some gypsum into the liquor to bring it up a little higher. You could also leave the darkest malts out of the mash for 45 minutes and just toss them in at the end to get all the dark goodness out of them, but after most of the stuff has converted.
 

downpantera

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I thought this was the case as well, that the acid rest was more to lower the pH into a good range due to higher alkalinity levels in water. If you're trying to raise the pH in your RIS mash, you can toss some gypsum into the liquor to bring it up a little higher. You could also leave the darkest malts out of the mash for 45 minutes and just toss them in at the end to get all the dark goodness out of them, but after most of the stuff has converted.
Gypsum will lower your mash pH, not raise it. To raise the pH, use baking soda or chalk. You need very little baking soda, say ~ 1 gram to go up by 0.1, depending on thickness. You need a whole lot more chalk, around 3 - 5 grams.
 

erikpete18

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Ha, crap, that's what I get for trying to use the common name. Yes, chalk (CaCO3) or baking soda (NaHCO3) is what you want, not gypsum (CaSO4). Its the carbonate ion (CO3) that will help to raise the pH. I've not used baking soda, but I know with chalk that it doesn't like to dissolve very well. Throwing it into the mash itself (instead of the liquor) will help to dissolve more of it since the mash is acidic, but you'll still have to give it 5-10 min to dissolve well and stabilize, then you can check the pH.
 

Mustard

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I know this is an old post but looking for some help. I have fairly high alkiline water I'm using the PH test strips, I know they aren't very accurate BUT I'm new to brewing I've just brewed my 3rd AG batch. My PH was reading at the top end for my 3 beers I've done (6.2). I would prefer to stay away from added Gypsum or any other addictives. (I'm sure they are fine but would like to be able to do it without). So I'm looking for guidence on an acid rest. 95-100 degrees and for how long? is there a length time per pound of grain? I usually mash at 1.5g/lbs of grain. How many points would you expect an acid rest to drop the PH
 

cooper

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I know this is an old post but looking for some help. I have fairly high alkiline water I'm using the PH test strips, I know they aren't very accurate BUT I'm new to brewing I've just brewed my 3rd AG batch. My PH was reading at the top end for my 3 beers I've done (6.2). I would prefer to stay away from added Gypsum or any other addictives. (I'm sure they are fine but would like to be able to do it without). So I'm looking for guidence on an acid rest. 95-100 degrees and for how long? is there a length time per pound of grain? I usually mash at 1.5g/lbs of grain. How many points would you expect an acid rest to drop the PH
What I usually do is put all of my water into my HLT and adjust the PH down to 5.5 with either Phosphoric or Lactic acid. I like to use soft water and add my dark grains in during the vorlauf so I only have to worry about keeping the PH from moving UP any further.

The Gypsum or Calcium Chloride additions are more about getting the Ca levels to at least 100ppm than making major adjustments to the PH levels. Most people like to use the CaCl to help accentuate the malty profile and use the Gypsum to accentuate the hops in IPAs and such.
 

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Adjusting your water with phosphoric acid is an efficient, flavor neutral means to neutralize "high" alkalinity to ensure your mash will get to the correct PH.

The alkalinity of my water is in the 160 range. I add phosphoric and camden tabs (to eliminate chloramines) when preparing my brewing liquor. My usual acid addition is around .75-1 ml per gal depending on the malts used in the mash. This usually runs to 6.5-7.5 ml for the water required for me to complete a 5 gallon batch. Super easy and eliminates any kind of acid rest.
 

Mustard

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I have a Black IPA in the secondary right now. I was hoping the dark malts would bring the PH down. It still read 6.2
 

cooper

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I have a Black IPA in the secondary right now. I was hoping the dark malts would bring the PH down. It still read 6.2
Before I was able to bring my PH down to somewhere between 5.1 and 5.8 my beer tasted really astringent, like I had mixed rubber bands into it or something. You might be all right with it around 6 but I' would try the recipe again with some acid to bring the PH down less than 6
 

Mustard

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Before I was able to bring my PH down to somewhere between 5.1 and 5.8 my beer tasted really astringent, like I had mixed rubber bands into it or something. You might be all right with it around 6 but I' would try the recipe again with some acid to bring the PH down less than 6
The test strip only goes to 6.2 I think its probably more but don't know for sure
 

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If you don't have a water report, you need to get one. Otherwise you will be doing a lot of guessing about what you are trying to adjust.

If you are on well water, you will probably need to have a "Ward's lab" report done. If you use city water, do a google search to see if someone has posted their Ward's lab report for your town. You can save some $ and time and at least have an idea about what you are brewing with.

Once you know what you are working with, acid additions and water modifications are possible. I'd avoid making any adjustments before that though.
 

cooper

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I agree with Foosier. There are quick ways to get it in the ball park but if you really want to understand what's going on with your water then you need to get a water report and see where your numbers are coming in at.

I have also heard of people's municipal water profile changing over the year so they've used nothing but distilled water and built up the profile by adding their own acids to adjust the PH and minerals according to the style they're brewing.

It's all about how much studying you want to do and how much you'd like to learn about what makes it all work.
 

Mustard

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If you don't have a water report, you need to get one. Otherwise you will be doing a lot of guessing about what you are trying to adjust.

If you are on well water, you will probably need to have a "Ward's lab" report done. If you use city water, do a google search to see if someone has posted their Ward's lab report for your town. You can save some $ and time and at least have an idea about what you are brewing with.

Once you know what you are working with, acid additions and water modifications are possible. I'd avoid making any adjustments before that though.
Ya I'm on well water and have been putting off getting the water report.
 

Foosier

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Well water does make it tough. You really need a water report to use your well water and know what you are working with. You might still do a google search to see if anyone in your area has posted a wards lab report from their well, but chances are you won't have too much luck there.

As cooper said, an easier alternative is to use store bought water. That is certainly more expensive, but it can make a big difference and you will know what you are working with. The "Brewing water chemistry primer" sticky in the brewing science forum has great advice on how you can start from a base of Reverse Osmosis filtered water (or distilled) and easily build a good water for brewing by a few simple additions. I highly recommend reading that post in depth before you try going farther with water modifications.
 

RM-MN

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I know this is an old post but looking for some help. I have fairly high alkiline water I'm using the PH test strips, I know they aren't very accurate BUT I'm new to brewing I've just brewed my 3rd AG batch. My PH was reading at the top end for my 3 beers I've done (6.2). I would prefer to stay away from added Gypsum or any other addictives. (I'm sure they are fine but would like to be able to do it without). So I'm looking for guidence on an acid rest. 95-100 degrees and for how long? is there a length time per pound of grain? I usually mash at 1.5g/lbs of grain. How many points would you expect an acid rest to drop the PH
Since you seem to know that the pH strips aren't very accurate, why use and believe them. A digital pH meter doesn't have to be really expensive and you don't need super accuracy for making beer. I'd suspect that even a cheap digital pH meter is more accurate than your pH strips. http://www.ebay.com/sch/i.html?_fro...2.A0.H0.Xph+meter.TRS0&_nkw=ph+meter&_sacat=0
 
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