Decoction - Probably not needed but would like to

[DeadYetiBrew]

Ok, so i got a Traditional Bock and an Oktoberfest coming up to be brewed.

I know that with the malts you get now it isn't as important as it use to be. However, i like the fact that it will help develop the malt profile and give the beer the depth i love. I've never brewed by decoction but would like to experience it and say that i have, to have it under my brew belt. I know they take time but i'm jobless so no big deal there.

So far this is what i understand of decoction (i've read a couple postings but still a little foggy). You basically mash in at one rest temp (depending on how many decoctions you are going to do) then you remove some of the grist and water and boil for a time, making sure not to scorch the grain. When this is added back to the main mash it should bring you up to your next rest temperature. Continue on with more decoctions or go to sparging.

My usual brew day consists of mashing then batch sparging and the boil. I'm still trying to dial down my equipment too. Now that i have a cooler with virtually no deadspace i thought it was a good time to try something a little harder.

So, tell me, how hard is it really or is it as i think, just time consuming?

 

[Iordz]

I don't think it is too hard, only time consuming, like you said. The biggest problem I have had was reaching the next mash temperature. I pull a third of the mash and boil it, then add it back and I'm still a few degrees off. Basically you have to do it once or twice to get the hang of it and to adjust your methods so that they will work with your system. I learned that I had to pull about and extra two quarts and then I was able to reach my mash steps. The other major issue is the constant stirring, you can't let the grains scorch, and this makes the heating a slow process.
I think you should give it a try. You will have to adjust for your system but that shouldn't be too hard. The most important thing is to decide whether you feel the decoction is worth it. Once you taste the beer you will know.

 

[Blender]

I did it one time with a hefewiezen. I could not get the mash temp raised by just the decoction so I had to pull some wort out and heat that to get to 150. I would think you will need to take a good 1\3 of the mash and use that to decoct. I boiled for roughly 20 minutes and stirred constantly so you can't leave the kettle.

 

[Yooper]

I've done a few, and they aren't hard at all, especially if you have some brewing software to help you with the calculations. It's fun, too, kind of like "really" doing something. It feels like you're doing something besides waiting for conversion.

 

[Kaiser]

If you can wait another 2 wks, I should have the video ready. I found out that there isn't any on Youtube, so I'll make one. Read this, it shows you how to hit your temps with ease as well as decoction mashes that you can use for modern grains w/o worry.

Kai

 

[DeadYetiBrew]

If you can wait another 2 wks, I should have the video ready. I found out that there isn't any on Youtube, so I'll make one. Read this, it shows you how to hit your temps with ease as well as decoction mashes that you can use for modern grains w/o worry.

Kai

I read over that really quickly and it did clear up quite a few things (first stop). I have to wait on my freezer set-up (problem with electrical outlets) so 2 wks shouldn't be a problem, i'd appreciate it.

Also, i'm thinking the best way for me to learn would be to start a mash at the appropriate temp (130*F or so) then pull off a third (or whatever the amount) of the grist and liquid, then boil for a set time. Supposedly longer the better, so i'd think 30 minutes or so. Then add it back bringing the mash up to normal mash temp (152*F) and mash normally. Either mashing out with plain water or decocting again for a mash out then sparging.

 

[cefmel]

At the beginning of this year,I started including a decoction at mash out for all of my beers, in order to get some more melanoidins for malt flavor. At the end of mashing for 1 hour, take 50 % of the grist and bring it to a boil for 20 minutes. Add back to the mash tun and the temp should be around 170 degrees. Batch sparge and it's on to the boil.

Honestly, I can't tell the difference in malt character and there is also an increased chance of leaching tannins from the grain husks into the wort. I'm going to stop doing this except possibly for the Bocks.

 

[Kaiser]

Honestly, I can't tell the difference in malt character and there is also an increased chance of leaching tannins from the grain husks into the wort. I'm going to stop doing this except possibly for the Bocks.

I still have to find a taste and pin it to the decoctions. The differences seem to be subtle, but getting some more tannins into the wort is also part of the decoction taste that is oftentimes decribed as a more robust taste which does go well with bocks and lagers but not with delicate beers like the German Pils. But the tannin extraction will not lead to an astringent beer like you get from oversparging.

Kai

 

[TexLaw]

Just don't forget your mini-saccharification rest when you pull that decoction. That extra bit of conversion often is important.


TL

 

[Glibbidy]

I've done a few, and they aren't hard at all, especially if you have some brewing software to help you with the calculations. It's fun, too, kind of like "really" doing something. It feels like you're doing something besides waiting for conversion.

Performing a decoction is the only time I actually break a sweat when I'm brewing.
The only part that's not fun doing a decoction, is the part when boiling decoction scalds my poor little hand while stirring. Perhaps I need a bigger paddle.

 

[the_bird]

Performing a decoction is the only time I actually break a sweat when I'm brewing.
The only part that's not fun doing a decoction, is the part when boiling decoction scalds my poor little hand while stirring. Perhaps I need a bigger paddle.

I've got a five-foot SS mash paddle I'd lend you, if you want to drive out to Pepperell this weekend and pick it up...

I've got to get better at decoctions, I always have a b*tch of a time hitting my rest temps (probably not pulling enough). I always blow right through the sac rest temp, too. Kaiser, I'm counting on your help!

 

[bradsul]

I have been doing a mash-out decoction successfully for quite a while now. Whenever I've tried to do a step up from say a protein rest to sacc. rest however I always WAY undershoot my temps. I think I'm just too much of a sissy and take way too little grain when I pull the decoction out.

I can't wait to see a video of someone who's successful at it!

 

[the_bird]

I have been doing a mash-out decoction successfully for quite a while now. Whenever I've tried to do a step up from say a protein rest to sacc. rest however I always WAY undershoot my temps. I think I'm just too much of a sissy and take way too little grain when I pull the decoction out.

I've thought about just doing a mash-out decoction, but then someone brought up the point that doing a decoction at mash out (at least, if I was to pull the thick part) would end up releasing a good amount of starch, which would not be converted since I was, in fact, mashing out. No idea if this is valid or not. When you pull for a mash-out decotion, are you pulling thick or thin?

 

[bradsul]

I've thought about just doing a mash-out decoction, but then someone brought up the point that doing a decoction at mash out (at least, if I was to pull the thick part) would end up releasing a good amount of starch, which would not be converted since I was, in fact, mashing out. No idea if this is valid or not. When you pull for a mash-out decotion, are you pulling thick or thin?

I heard that too, so I pull very thin. I basically run about 5-6 litres of the mash out through my sparge manifold, then scoop just enough grain to make it semi-thick (it won't hold my mash paddle up for example). I doubt I'm actually getting any real benefit out of the small amount of grain but it does allow me to do my mash-out without infusing more water. Plus, benefits or not, it's more fun.

 

[the_bird]

Do you think you get any melanoidin formation from pulling just the thin part? Doesn't the flavor element of a decoction come from the grain husks?

 

[bradsul]

I think it does come mostly from the grain (though I'm not sure, seems like common sense since we don't get it much from our regular wort boil). I doubt I get any noticeable decoction flavour benefits.

 

[Kaiser]

The flavor comes from the husks and melanoiden's. Though I have to say that I have a hard time picking out this flavor.

Starch release for the mash-out decoction is fine since the alpha amylase is still active during mash out ans should be able to take care of the stach. That's why you don't mash out higher than 170 *F b/c you might stop that enzymatic activity. When I do triple or nowdays the large double decoction I tend to make the mash-out decoction thin to minimize the starch release b/c the enzymes are already weakened. But if you have a single decoction, it can be pulled thick, even for mash-out. Unless you have 100% munich malt, there will be enough enzymes to take care of the additional starch.

Undershooting the temp is a common problem that I fix by pulling more and return only as much decoction as is needed to get to temp. The rest I let cool down and add a little later.

Most brewers seem to pull the decoctions way to thick and try to heat to fast. This is when you need to stir a lot.

Kai

 

[AdIn]

...

Starch release for the mash-out decoction is fine since the alpha amylase is still active during mash out ans should be able to take care of the stach. That's why you don't mash out higher than 170 *F b/c you might stop that enzymatic activity.
...
Kai

That's kind of new to me. I should give it a try. Is there a place to read about it in more details. It contradicts a bit to what other books say, but if it works - should be a big time saver.

 

[TexLaw]

Most brewers seem to pull the decoctions way to thick and try to heat to fast.

No joke on that, Kai. When I decoct to go from a protein to a saccharification rest, it often takes 30-45 minutes for the whole process, sometimes a little more, depending on how the mini-rest goes and how long I want to boil the decoction. Even then, I'm rushing it.

I also pull thin for mash out decoctions.


TL

 

[kmlavoy]

+1 on brewing software. Not to poo-poo what someone else said, but I've done decoction mash outs on my last 2 brews, and I took nowhere near 50% of the grist for the decoction. I do 5 gallon brews, and last time, I took 5.5 quarts. I use promash, and the mash schedule stuff calculates your decoction volume for you when you put your temps in. It all depends on your water to grist ratio in the mash, and how thick your decoction is supposed to be.

Way easy. Just remember to take your decoction out slowly, and add it back slowly. No need to take a chance scalding yourself, or doing a little hot side aeration to your brew. I use a 2 cup pyrex measuring cup to do the pull.

 

[TexLaw]

I use a long ladle to get down to the bottom of the tun when pulling a thick decoction.


TL

 

[Kaiser]

That's kind of new to me. I should give it a try. Is there a place to read about it in more details. It contradicts a bit to what other books say, but if it works - should be a big time saver.

It contradicts what Palmer writes, but I woudn't consider him an authority on that. I have to check Noonan and other books at home.

Most of what I have learned so far is written here and I don't consider myself an authority either. When German brewers pull decoctions they stop the stirer in the mash tun, wait for the grain to settle and then pump it from the bottom of that tun into the kettle. However thick it settled to, this is how thick the decoction is going to be. To my knowledge there is no device that strains the grains to thicken the decoction beyond that point. And if you look at the design of a heated mash-tun used for decoctions, it only has a little paddle on the bottom to prevent scorching (here page 17 lower left). This paddle is not going to stir a decoction as thick as it is oftentimes suggested. The mash thickness numbers I read are about 4 L/kg (2 qt/lb) for the main mash and 2 L/kg (1 qt/lb) for the decoction. Darker beers may have a thicker main mash (about 3.5 L/kg).

Kai

 

[the_bird]

I'm going to try a thinner main mash on the Pilsner this weekend. I'm a little leery of going 2qts/lb just in case I end up needing to infuse to hit temps, but I'll probably go with ~1.7 (versus my standard 1.25).

Kai, Tex, et al, what's a classic EuroPils want? Double decoction? Protein rest to sac rest, then sac rest to mashout? I'm thinking a short rest ~122°-125°, pull a decotion, boil for ~10 minutes, hopefully hit 150°, maintain that for an hour, then raise to 170°ish via a mashout decotion.

 

[Kaiser]

I'm going to try a thinner main mash on the Pilsner this weekend. I'm a little leery of going 2qts/lb just in case I end up needing to infuse to hit temps, but I'll probably go with ~1.7 (versus my standard 1.25).
Kai, Tex, et al, what's a classic EuroPils want? Double decoction? Protein rest to sac rest, then sac rest to mashout? I'm thinking a short rest ~122°-125°, pull a decotion, boil for ~10 minutes, hopefully hit 150°, maintain that for an hour, then raise to 170°ish via a mashout decotion.

The classic German Pils is not brewed with decoction anymore. B/c it is supposed to be a very delicate beer, the robust flavor of the deoction doesn't fit. So much for the current state of German Pils brewing and what I have found.

But you should do a decoction for your's. I suggest a Hochkurz mash done as double decoction. Dough-in at 133 *F, infuse to 140 F (maltose rest) , pull decoction after 30 min, boil for 10 min, return to reach 158 F (dextrinization) hold for 30 min, pull mash-out decoction, boil 10 min and mash-out at 169 *F. The benefit of this schedule is that you don't have a long protein rest or are able to skip this rest altogether. If you want to save the first step, you could also dough-in at 140 *F.

Kai

 

[the_bird]

What's the benefit of doughing-in at 133° instead of at the maltose rest?

 

[bradsul]

I have Noonan's New Brewing Lager Beer showing up in a couple days hopefully. I don't have lagering capability but I heard the decoction sections were priceless for the homebrewer.

 

[Kaiser]

What's the benefit of doughing-in at 133° instead of at the maltose rest?

Having a protein rest and being able to use infusions to get to the maltose rest, which allows me to hit the temp more precisely.

But I'm easily convinced that this is not necessary anymore as a lot of recent recipes from Germany, that I came across, dough in at the maltose rest or a little below. Some call the dough-in between protein and maltose rest an "enzyme" rest which seems to imply that they want the enzymes to get better dissolved before they will have to do work at higher temperatures.

Kai

 

[the_bird]

I have Noonan's New Brewing Lager Beer showing up in a couple days hopefully. I don't have lagering capability but I heard the decoction sections were priceless for the homebrewer.

I've got Noonan's book, it's great - but it also helps to have guys like you, Tex, and Kai to ask questions of - it's not the easiest material to understand!

Incidentally, I was re-reading a chapter of it, and came across all of the detailed information on the techical differences between what ale yeasts ferment and what lager yeasts can ferment... INFORMATION THAT WOULD HAVE EARNED US A GODDAMN KEG OF RAY MCNEILL'S BEER!

 

[DeadYetiBrew]

So how does this look?

I will do an infusion to get the first rest to 133*F there i will protein rest for however the hell long it takes me. I plan to let all of the grain rest for about 5 minutes before pull the decoction. I'll pull and heat till 152, cut heat, put on a lid and let rest itself for atleast a good 10-15 minutes, then i'll turn back on the heat and boil the decoction for about 20 minutes. The times are all abouts because i have no idea how it's going to go being the first time doing a decoction. Adding back into the mash to bring it up to 152*F. Then, depending on how it's going, I'll either pull once everything is uniform temp or let it all rest still. I'll pull for mash out, something i don't even really do with a single infusion and batch sparge, since i'm going to i figure i might as well decoct it again for the mash out. So i'll boil again to bring the mash to 170. Rest for 10 minutes at mash out. Run it off, then sparge with 170*F water and continue to the boil.

Does that sound correct and is my knowledge thus far good about the process?

 

[Kaiser]

So how does this look?
I'll pull and heat till 152, cut heat, put on a lid and let rest itself for atleast a good 10-15 minutes,

I suggest heating the decoction to 158-160 F and letting it rest there for 10-15 min. This way you'll get more conversion. Also, if you wrap the pot in an old blanket, it will hold its temp better.

Otherwise it looks good.

Kai

 

[DeadYetiBrew]

I suggest heating the decoction to 158-160 F and letting it rest there for 10-15 min. This way you'll get more conversion. Also, if you wrap the pot in an old blanket, it will hold its temp better.

Otherwise it looks good.

Kai

Ok, awesome, after you figure it out it really isn't that hard.

Question of decocted boil time. I heard the longer you go the more flavor it will extract, is there a point where it becomes either A) Too Much or B) No Difference?

For instance for a bock could i do a 1 hour boil time with each decoction or would the difference between that and 30 minutes be pointless?

The above was for my Oktoberfest, was wondering because i have a bock coming up too.

 

[Kaiser]

I don't think very long boils are good. For lighter beers (Maibock, Bohemian Pils) I'd boil for 10 - 15 min. For darker beers (Bock, Maerzen. Dunkel) you can boil for 20 - 40 min. I don't think it makes much sense to go beyond that. Keep the evaporation in mind as you may end up with to little decoction volume at the end. Check your volume (dip stick, markings) towards the end of the boil and add water to compensate if necessary. You can also boil decoctions with a lid on to reduce evaporations and boil-off. Any DMS created during the decoction would be boiled off during the hop boil if it doesn't get out during the decoction boil. But watch out for foaming-up when you put a lid on.

Kai

 

[DeadYetiBrew]

I don't think very long boils are good. For lighter beers (Maibock, Bohemian Pils) I'd boil for 10 - 15 min. For darker beers (Bock, Maerzen. Dunkel) you can boil for 20 - 40 min. I don't think it makes much sense to go beyond that. Keep the evaporation in mind as you may end up with to little decoction volume at the end. Check your volume (dip stick, markings) towards the end of the boil and add water to compensate if necessary. You can also boil decoctions with a lid on to reduce evaporations and boil-off. Any DMS created during the decoction would be boiled off during the hop boil if it doesn't get out during the decoction boil. But watch out for foaming-up when you put a lid on.

Kai

That was going to be a question too. How bad of evaporation do you get with 30 minute boils? i would assume the evaporation rate is of course the same. So at the end of a 30min boil you could add some water back. I can see how it might effect the rest of the mash adding less back. So you could even calculate the evaporation amount and add that in clear water at the beginning of the decoction.

 

[zoebisch01]

My first decoction, I hope it turns out ok!

So I decided to try this with my Oktoberfest. I was shooting for a 20 minute Protein rest, 156 °F Saccharification rest and then mashout. However, I pulled the decoction after strike and proceeded to heat it to around 156 and let it start to convert and then boil it and add it. That went fine and I hit the target temperature exactly.

What did happen though I am not sure what took place. It took hours to convert, even to the point where I had to pull more decoction to restabilize my Saccharification rest temp. I had a lot of flour in it (I had adjusted the mill for the brew I did before that and forgot to retest before milling) and the last brew I had with a large amount of flour seemed to take forever as well to convert? I have no idea if that has anything to do with it.

I do realize you denature the enzymes in the decoction volume, but the recipe didn't have anything but Vienna and Munich, but still I am suspecting the denaturing of that portion may have been the problem? I know 156 °F is at the way high end of things, but still I should have had plenty of alpha amylase working. I am really wary about attempting another decoction now . I didn't get to bed until 1:00 am because of it. The other thing is I suppose the pH could have gone out of wack, but I am not set up to measure this.

 

[Kaiser]

How bad of evaporation do you get with 30 minute boils?

This time, I lost about 1.5L out of a 11L decoction. This was a 30 min boil and I added the water back after I used part of the decoction to infuse to the protein rest. If you plan to use all the decoction to get to a rest, add the water and wait for it to come to a boil again. Otherwise your decoction temp will be off (obviously).

Zoebish, sorry to hear that you had problems with your decoction. But let me try to address some of them:

I pulled the decoction after strike and proceeded to heat it to around 156 and let it start to convert and then boil it and add it. That went fine and I hit the target temperature exactly.

Good job hitting your target temp. This seems to be a common stumble-stone for most. But there is not need to match the saccrification rest temp when converting the decoction. Just heat to 160-164F, wrap the pot in blankets and let it sit for 10-20 min. After that it should be pretty much converted. Full of dextrines, but converted.

What did happen though I am not sure what took place. It took hours to convert, even to the point where I had to pull more decoction to restabilize my Saccharification rest temp. I had a lot of flour in it (I had adjusted the mill for the brew I did before that and forgot to retest before milling) and the last brew I had with a large amount of flour seemed to take forever as well to convert? I have no idea if that has anything to do with it.

Yes, this happened to me before. But I had a 100% Munich malt triple decoction for a Doppelbock. I ended up adding some fresh pilsner malt to get things going again. No fun. But you should have had quite a bit of the more enzymatic strong Vienna malt in there which helps. Here are a few tips:

- make decoctions thin mashes (1.75 - 2 qt/lb) and pull a thick decoction. Not to thick that it gives you problems when stiring it, but thick enough so you leave most of the liquid in the main mash. This is where the enzymes are.

- make sure you convert the decoction (10 - 20 min at 160-164F). These enzymes will be gone, so try to get the most out of them

- If the mash is not converted after 45-60 min at sacc rest temps, give it anothetr 30 min. Don't worry about the temperature droping. If you keep pulling decoctions and boiling them you are going to weaken the enzymes.

- If the mash still doesn't convert, pull your mash-out decoction to get you to a mash-out temp of about 164 F. This is prime a-amylase temp and should get things kick-started. Let it sit at this temp for 10 min and check conversion. You are not looking for a completely negative iodine reaction. Some color is still fine. It should just not be deep blue/purple. An reaction like this:

would be perfectly fine.

- after at most 30 min at this rest start recirculating until the wort runs reasonably clear and test a sample of that wort with iodine. If you only have a slight reaction, you are fine to go. I actually found that the mash may not show complete conversion, but when I then run-off into the kettle, the wort is converted. And that's what counts.

- If even the run-off after having the mash for 30 min at 164 shows a significant reaction to iodine, you are only left with adding more malt. 5-10% Pale or Pilsner should do it. If not, lauter and ferment a not fully converted wort. You could add Beano in the fermenter, but it would be hard to make it stop.

The other thing is I suppose the pH could have gone out of wack, but I am not set up to measure this.

Could have been the problem to if this was the first time you brewed a beer with that grist and the water you had.
Kai

 

[zoebisch01]

Good job hitting your target temp. This seems to be a common stumble-stone for most. But there is not need to match the saccrification rest temp when converting the decoction. Just heat to 160-164F, wrap the pot in blankets and let it sit for 10-20 min. After that it should be pretty much converted. Full of dextrines, but converted.

Ahh, yeah makes sense.

- make decoctions thin mashes (1.75 - 2 qt/lb) and pull a thick decoction. Not to thick that it gives you problems when stiring it, but thick enough so you leave most of the liquid in the main mash. This is where the enzymes are.

Ok, I did a 1.5 ratio and I pulled about half and half. That probably contributed to the problem.

- make sure you convert the decoction (10 - 20 min at 160-164F). These enzymes will be gone, so try to get the most out of them

Yeah, when I started in I realized that it would be the best idea to convert what I had taken out, but didn't think to use the high temp.

- If the mash is not converted after 45-60 min at sacc rest temps, give it anothetr 30 min. Don't worry about the temperature droping. If you keep pulling decoctions and boiling them you are going to weaken the enzymes.

That's something that has always puzzled me. We always talk about higher mash temps, and mashout, and we know that it takes time for the enzymes to denature...but once the mash has been in a higher regime which favors the action of the alpha amylase for a fairly long time, what is the net result of the temperature dropping down into the beta-ideal temps? Will this negate the effect of the original high mash temperature? This ties into the mashout step as well I suppose.

- If the mash still doesn't convert, pull your mash-out decoction to get you to a mash-out temp of about 164 F. This is prime a-amylase temp and should get things kick-started. Let it sit at this temp for 10 min and check conversion. You are not looking for a completely negative iodine reaction. Some color is still fine. It should just not be deep blue/purple. An reaction like this:

would be perfectly fine.

Yeah, it was odd. I usually recirculate about a few cups of wort just to make sure I am getting a good representation of what is going on (i.e. if there are hot spots/etc) and test. I was getting the dark color reaction until after I bumped the temperature back up, and even then it still took a good 30 minutes. Now knowing it is ok to do so, if I attempt this again I'll keep the 164 °F in mind.

- after at most 30 min at this rest start recirculating until the wort runs reasonably clear and test a sample of that wort with iodine. If you only have a slight reaction, you are fine to go. I actually found that the mash may not show complete conversion, but when I then run-off into the kettle, the wort is converted. And that's what counts.

At one point, after taking a few conversion tests and getting mixed results, I thought...well, maybe I should just lauter. I started to do this and then gently mixed about 1.5 g of the runoff and looked at that with the test. It went black streaks with mohogany edges and now I was starting to sweat! So I set the mash tun on the floor and gently re-drained that liquid back into the tun. I tested the temp again at this point and I was dropping into the high 140's (149 °F iirc) so that's when I decided to bump it by pulling a decoction.

- If even the run-off after having the mash for 30 min at 164 shows a significant reaction to iodine, you are only left with adding more malt. 5-10% Pale or Pilsner should do it. If not, lauter and ferment a not fully converted wort. You could add Beano in the fermenter, but it would be hard to make it stop.

Yeah I had been thinking at this point, man should I add more grain and was getting really antsy. Especially with a beer that will be aging for 6 months.

Could have been the problem to if this was the first time you brewed a beer with that grist and the water you had.

That's a good point. I suppose I am somehow relating this to my one soured mash experiment where conversion took hours as well. I suspect the pH of my soured mash pushed it out of the low range for optimal enzyme activity. It makes no sense now that you mention it that last nights experience would have to do with pH. I guess I was wondering that if there were any significant pH reduction in the protein rest regime, but I was at the high end for the protein rest (130 °F).

Thanks for the tips and insight !

 

[Kaiser]

I suppose I am somehow relating this to my one soured mash experiment where conversion took hours as well. I suspect the pH of my soured mash pushed it out of the low range for optimal enzyme activity. It makes no sense now that you mention it that last nights experience would have to do with pH. I guess I was wondering that if there were any significant pH reduction in the protein rest regime, but I was at the high end for the protein rest (130 °F).

Yes, that was always my concern when hearing about soured mashes. When I do them I'd convert the to be soured mash, let it cool it 35 *C and toss in a handful of malt to inoculate with lacto. I would then add the sour mash after the main mash has been converted to make sure the mash-ph doesn't get out of whack unless you want to use a sour mash (or part of it) to correct mash pH.

Though the decoction process slighltly changes the mash pH, it is not significant to get it out of whack.

Raising the mash temp well into the a-amylase range is basically doing a 2-stage saccrification (common in German mashing) where the 1st stage is for creating maltose and the 2nd stage is for getting the remaing starch converted. Unless you have enough a-amylase activity you won't get complete conversion at the common 150-154 F rest. Most mashes however have enough enzymes to be able to fully convert w/o having to be raised to 160+. Only large amounts of Munich and decoction mashes may have to.

Once I have the video done I should also write a page about trouble shooting decoction mashes and how to fix them on the fly.

Kai

 

[pjj2ba]

That's a good point. I suppose I am somehow relating this to my one soured mash experiment where conversion took hours as well. I suspect the pH of my soured mash pushed it out of the low range for optimal enzyme activity. It makes no sense now that you mention it that last nights experience would have to do with pH. I guess I was wondering that if there were any significant pH reduction in the protein rest regime, but I was at the high end for the protein rest (130 °F).

Thanks for the tips and insight !

If your water is like mine, I find it to be very good for Oktoberfests. Of the major brewing cities, my water (so I suspect yours too) is most similar to that of Munich. For Oktoberfests I don't make any pH adjustment to the mash, but I do buffer my sparge water if for nothing else, peace of mind. I brewed two 7.5 gal. batches yesterday and while I didn't do a decoction, I did do a step mash, starting at 132F and Saccharification at 152 F (1 hr). I didn't do an iodine test but based on my OG's I got great conversion (3:1 Vienna:Munich). I might suggest double checking your thermometer accuracy. Also, Kai's comment about a thick decoction sounds like a possible cause. One of these days I have to try a decoction.

 

[boo boo]

OK those of you doing decocotions..... are you using well modified malt?

I have read that doing so with well modified malt will lose you some of the head promoting protiens and in the processs leave the brew a bit thin.

German pils brewers have used undermodified malt to brew with to acheive the maltiness associated with continental pils.

David Miller in his book Continental Pilsener says it works good with any malt as there is relatively little protien degradation in the mash anyway. He also says using 6 row barley isn't recommended because of possible tannin extraction.

 

[zoebisch01]

Once I have the video done I should also write a page about trouble shooting decoction mashes and how to fix them on the fly.

Kai

Sounds great. Thanks for the help.