Cool Temps Outdoors and Maintaining Mash Temps

[Nubiwan]

North of the border newbie BIAB brewer here.

I have to move the operation outdoors while the family is all on lockdown.

I am being farmed out to the garage, which is unheated, completely separate from the house, and day time temps here are still only 12 C of 50 F. I will be able to stay clear of the wind if necessary, but I cant heat my garage in any way. Its cold in there.

This will present a potential issue around keeping my mash temp constant. Will wrapping my kettle in a sleeping bag still be enough? Can I just leave the propane on low flame (obviously minus the sleeping bag)? Does the low burner just introduce a hot spot at the bottom, or even a risk of scorching my bag?

Planning on going with an element in my Kettle in the next month or so, as I do have a panel out there with a free 30A fuse, but I will likely do a couple batches on my propane burner.

Anyone coping with this "cold outside" issue, care to offer come advice.

 

[RPh_Guy]

Will wrapping my kettle in a sleeping bag still be enough? Can I just leave the propane on low flame (obviously minus the sleeping bag)? Does the low burner just introduce a hot spot at the bottom, or even a risk of scorching my bag?

I highly recommend to stick with the sleeping bag. Direct heating does create hot spots in my experience and can lead to low attention, even with stirring. It's ok if it drops a few degrees during the mash.

 

[camonick]

Sleeping bags, moving blankets, comforters, etc. or any combination work well. I also put an old pillow on my lid before I put the blanket on for extra insulation. I’ve brewed in my unheated shop down to about 20° F without too much heat loss.

 

[Jag75]

Dang , blankets and pillow talk......I'm ready for a nap

 

[Ultryx]

A sleep bag is a good bet or a blanket. If you want to really step it up buy some of the reflective insulation and wrap it around your kettle with small cut outs for your ball valve and handles. Keep that wrapped on there during your mash and then throw a sleeping bag or blanket around that.

 

[Mac MacFarlane]

I did my first biab last week, I'm also from Canada and had similar temps when I did it. When I did my mash I used a winter sleeping bag, i started my mash at 156f and in 60min It dropped to around 150f. If you do use a sleeping bag watch the bottom of your kettle I melted a bit of the sleeping bag when I first put it on.
I was also battling winds when I did it.

 

[Ultryx]

I did my first biab last week, I'm also from Canada and had similar temps when I did it. When I did my mash I used a winter sleeping bag, i started my mash at 156f and in 60min It dropped to around 150f. If you do use a sleeping bag watch the bottom of your kettle I melted a bit of the sleeping bag when I first put it on.
I was also battling winds when I did it.

I try to pull my setup behind our wall where the winds usually come in off the coast. Those are the tougher days. I still haven't devised something to place below to minimize heat loss from the bottom.

 

[Nubiwan]

I did my first biab last week, I'm also from Canada and had similar temps when I did it. When I did my mash I used a winter sleeping bag, i started my mash at 156f and in 60min It dropped to around 150f. If you do use a sleeping bag watch the bottom of your kettle I melted a bit of the sleeping bag when I first put it on.
I was also battling winds when I did it.

What's with weather in Canada? It's brutal out east. Least we only had 250 COVID case. To bloody cold for the virus. Even the virus don't like it here.

Anyway, anticipating doing it inside my garage, out of the wind, but I too think my temp will take a similar temperature hit. Been reading up on the values of mash temps and quality on brulosophy, and much of their testing, around such variances (temps, trub, etc) has been largely inconclusive. Particularly the one references the exact same beer made with mash temps at 148 and 160. Final beers were hardly indistinguishable to hardened brewers. Even though the ABV was predictably different.

Makes me wonder if I should really worry about it, as long as I keep my mash temp over 150, and under 158. Every beer you make can be different in some minor way.

 

[RM-MN]

All of you seem to be very concerned that you cannot maintain a constant mash temperature over the course of an hour for the mash. None of you have determined how long it takes for conversion on your system. Conversion is the only time the temperature is critical and if you get full conversion in 20 minutes you don't need to worry about the temperature for the next 40 minutes. How long does it take for your system? I BIAB and mill the grains to near flour. My long mashes are 30 minutes because conversion is complete well before that and I simply need to wait for flavors to be extracted.

 

[VikeMan]

All of you seem to be very concerned that you cannot maintain a constant mash temperature over the course of an hour for the mash. None of you have determined how long it takes for conversion on your system. Conversion is the only time the temperature is critical and if you get full conversion in 20 minutes you don't need to worry about the temperature for the next 40 minutes.

Once conversion (starched to non-starches) is complete, there is still amylase enzyme activity, making the wort more fermentable the longer the mash goes on. So even though temperatures at that point may not be "critical," they do affect the beer.

 

[Nubiwan]

All of you seem to be very concerned that you cannot maintain a constant mash temperature over the course of an hour for the mash. None of you have determined how long it takes for conversion on your system. Conversion is the only time the temperature is critical and if you get full conversion in 20 minutes you don't need to worry about the temperature for the next 40 minutes. How long does it take for your system? I BIAB and mill the grains to near flour. My long mashes are 30 minutes because conversion is complete well before that and I simply need to wait for flavors to be extracted.

I am preparing my first BIAB, so efficiency and conversion rates are unknown at present. Been doing extract brewing till now. Trying to nail down a personal process. The more I read on stuff, the more I just think I set myself a few standards, and let fly. Much of the literature is conflicting on some subjects, if not unproven, just assumed.

Things such as chilling wort after boil, trub amount in fermenter, grain milling, mash temp differences on final beer quality, etc. etc. Many conflicting results Vs expectations.

I read somewhere - perhaps on a John Palmer posting - that he advises against grinding to a flour. Hang on...... There it is below.

What do you believe half the time? Regardless of the Palmer point, whats the problem having a little powdery fines in the wort, I would ask. Slower draining? I think I'd like to mill my grain to a flour, if not to get the most out of it.

Brulosophy site claims (and showed in Exbeeriment of theirs) that more trub / fines going into the fermenter actually improves clarity in beer I think I'd prefer a clear beer too, but many avoid too much trub in the fermenter for exact opposite reason, expecting clearer beer. Not sure how much trub you get from BIAB boil, if any, so will have to see.

Posted as information only - not to contradict anyone. Appreciate all the responses.

Extraction Efficiency
The efficiency of any brewing process depends primarily on the water to grist ratio that you are using. Generally speaking, the efficiency of BIAB should be between 74-84% for beer OG’s between 1.040 – 1.075, lower OG having higher efficiency than high OG. Crushing the grist finer/smaller will increase efficiency by a few percent, but I really don’t recommend doing that as it will increase the fines in your wort and slow the draining from the bag. If you plan your grain bills conservatively, you should easily hit your OG target. The BIAB water retention factor, 0.25 quart per pound of grain, is typically half that of a standard mash 0.5 quart per pound. In liters and kilograms, these numbers are roughly 0.5 liter per kilogram and 1 liter per kilogram. The weight of the grain pressing on the bag naturally drains more wort than a standard lauter tun, and you therefore get more wort from the same size mash, all else being equal.

 

[RM-MN]

Once conversion (starched to non-starches) is complete, there is still amylase enzyme activity, making the wort more fermentable the longer the mash goes on. So even though temperatures at that point may not be "critical," they do affect the beer.

According to the literature on brewing enzymes are quickly denatured at mash temps. People who do an overnight mash do not report any more fermentable wort than when they do a short mash.

 

[Nubiwan]

According to the literature on brewing enzymes are quickly denatured at mash temps. People who do an overnight mash do not report any more fermentable wort than when they do a short mash.

See what I mean? Very difficult to find a common ground in the "hobby". Religion-lol? Lots of variables to play with (whether BIAB or a 3 vessel job), and the simplicity of extract brewing is now very apparent to me.

I can literally churn out a decent enough extract brew in under an hour. Either Lager, IPA, Amber. Decent meaning, on a par with anything I buy at a store, or brew pub. Much fresher, and still plenty of room to manipulate the final flavour and aroma, with hopping or a partial mash.

 

[VikeMan]

According to the literature on brewing enzymes are quickly denatured at mash temps. People who do an overnight mash do not report any more fermentable wort than when they do a short mash.

Denaturing of enzymes is always a race against conversion and further breakdown of dextrins, but to say enzymes are denatured quickly at mash temps is an exaggeration. Yes, longer mashes do result in a more fermentable wort.

http://braukaiser.com/documents/Affects_of_mash_parameters_on_attenuation_and_efficiency.pdf
http://www.homebrewersassociation.o...pdf/2012/1616-04 Attenuation - Gregg Doss.pdf
There is, of course a limit. I would not expect the wort from an overnight mash to be more (or much more) fermentable than one from, say, a 3 hour mash. But in between "full conversion" and about 3 hours or so, mash length is a powerful knob to use to adjust fermentability.

ETA: I blame the cursed "iodine test," and it's presence in the original "How to Brew" for most of the misunderstading on this topic. A clear test doesn't mean the mash is "finished." It depends on your goals.

 

[VikeMan]

See what I mean? Very difficult to find a common ground in the "hobby". Religion-lol? Lots of variables to play with (whether BIAB or a 3 vessel job), and the simplicity of extract brewing is now very apparent to me.

There are lots of variables, and lots of beliefs, some based in science and data, and some not. Lots of things really are pretty clear cut, and some are not. You'll learn to separate the two as you gain experience.

 

[Nubiwan]

If I mash at the higher end of the temp range, 154 plus, then can I add some DME to improve efficiency/ABV? I realize it might not be considered improved efficiency, but I think you understand my question. Higher temp mash leads to less fermentable wort, correct?

I keep reading a guy says he puts "Glucol" in his mash so temp is not an issue. I assume this takes care of his fermentable. Not really sure what he means TBF.

 

[RM-MN]

Denaturing of enzymes is always a race against conversion and further breakdown of dextrins, but to say enzymes are denatured quickly at mash temps is an exaggeration. Yes, longer mashes do result in a more fermentable wort.

http://braukaiser.com/documents/Affects_of_mash_parameters_on_attenuation_and_efficiency.pdf
http://www.homebrewersassociation.o...pdf/2012/1616-04 Attenuation - Gregg Doss.pdf
There is, of course a limit. I would not expect the wort from an overnight mash to be more (or much more) fermentable than one from, say, a 3 hour mash. But in between "full conversion" and about 3 hours or so, mash length is a powerful knob to use to adjust fermentability.

ETA: I blame the cursed "iodine test," and it's presence in the original "How to Brew" for most of the misunderstading on this topic. A clear test doesn't mean the mash is "finished." It depends on your goals.

https://byo.com/article/understanding-enzymes-homebrew-science/

 

[VikeMan]

If I mash at the higher end of the temp range, 154 plus, then can I add some DME to improve efficiency/ABV? I realize it might not be considered improved efficiency, but I think you understand my question. Higher temp mash leads to less fermentable wort, correct?

I keep reading a guy says he puts "Glucol" in his mash so temp is not an issue. I assume this takes care of his fermentable. Not really sure what he means TBF.

Yes, you can add DME (or simple sugar) to get higher OG and higher ABV. And yes, higher mash temps do result in a less fermentable wort. (Actually, so do very low temps. It's actually a curve, with the sweet spot around 151F (per Kai's data).

I think they guy you're talking about is adding glycoamylase. I wouldn't suggest that unless there is something very specific you are trying to accomplish.

 

[Nubiwan]

Yes, you can add DME (or simple sugar) to get higher OG and higher ABV. And yes, higher mash temps do result in a less fermentable wort. (Actually, so do very low temps. It's actually a curve, with the sweet spot around 151F (per Kai's data).

I think they guy you're talking about is adding glycoamylase. I wouldn't suggest that unless there is something very specific you are trying to accomplish.

Agreed, on that last line.........

 

[Nubiwan]

Yes, you can add DME (or simple sugar) to get higher OG and higher ABV. And yes, higher mash temps do result in a less fermentable wort. (Actually, so do very low temps. It's actually a curve, with the sweet spot around 151F (per Kai's data).

I think they guy you're talking about is adding glycoamylase. I wouldn't suggest that unless there is something very specific you are trying to accomplish.

If my mash temp swings a range from say 154-149, over an hour say, then would I get benefits of both Alpha and Beta throughout my wort? Best of both Worlds. I am at a loss trying to understand why it has to be kept as constant as possible. Hope I have no repeated myself here.

 

[VikeMan]

If my mash temp swings a range from say 154-149, over an hour say, then would I get benefits of both Alpha and Beta throughout my wort? Best of both Worlds. I am at a loss trying to understand why it has to be kept as constant as possible.

I don't know that anyone has studied fermentability due to a "falling" mash temp. But you get benefits from both amylases at 154 and at 149. And everywhere in between. But the optimum (per Kai's data) is about 151. When you read something that says one enzyme or the other is "most active" at a certain temperature, that doesn't mean it's completely inactive at other temps.

 

[Nubiwan]

I don't know that anyone has studied fermentability due to a "falling" mash temp. But you get benefits from both amylases at 154 and at 149. And everywhere in between. But the optimum (per Kai's data) is about 151. When you read something that says one enzyme or the other is "most active" at a certain temperature, that doesn't mean it's completely inactive at other temps.

Think I'll aim for 153, then not worry if I lose 2-4 degrees. *I am expecting to lose a bit, indicated in OP. Maybe I won't. Trial and error.

 

[VikeMan]

https://byo.com/article/understanding-enzymes-homebrew-science/

Can you point me to anything in that BYO article that says wort fermentability does not increase with mash time? It does say that "at these higher temperatures the denaturation is so rapid that the enzyme is mostly gone in less than 5 minutes." Note the word "mostly," and note that he's doesn't give actual numbers, and that he's only talking about Beta Amylase.

P.s. - BYO article vs. actual data?

 

[Nubiwan]

Can you point me to anything in that BYO article that says wort fermentability does not increase with mash time? It does say that "at these higher temperatures the denaturation is so rapid that the enzyme is mostly gone in less than 5 minutes." Note the word "mostly," and note that he's doesn't give actual numbers, and that he's only talking about Beta Amylase.

P.s. - BYO article vs. actual data?

This brings another question forward for me. I see how some people suggest we add grain to the mash piece meal, and stir it in. Gradually adding the entire grain bill over several minutes. Does this not mean these initial grains have to suffer pretty higher "strike" temps. Not really a question, but the truth of the matter.

Are these grains not then sacrificed for the sake of avoiding some dough balls in the mash?

Most importantly, I fancy, what does it "really" Matter? A question I could ask in just about every thread, I feel.

Furthermore, based on this chart, why not just gradually heat my entire BIAB to 151 degrees from the off? What would it hurt. Whether I rest along the way or not? Has anyone tried this?

 

[VikeMan]

This brings another question forward for me. I see how some people suggest we add grain to the mash piece meal, and stir it in. Gradually adding the entire grain bill over several minutes. Does this not mean these initial grains have to suffer pretty higher "strike" temps. Not really a question, but the truth of the matter.

My advice is to gently combine and stir the grains and water as fast as you can without splashing or agitating too much, whether you're adding grains to water or water to grains. Either way, some malt is going to see high initial temperatures. But try not to overthink it too much.

 

[Nubiwan]

Update to all. Not sure why all the fuss.

I wrapped my quilt round the kettle, and pillow over the lid. The temps hardly budged from 153 for over an hour. My ground water is a frigid 45 degrees. Took me a while to get my water temps up, and I had to adjust my flame distance for the boil, which worked a charm. On the plus sde, my immersion chiller cooled the wort down to 70 in about 10 minutes, if that.

Unfortunately, i got my pre-mash water estimate wrong, so my SG was lower. The grains just did not soak up that much, and I let the bag drain back into the wort. That, and I was using some hot pot water to bring up the temps, and when I accounted for it, never released enough. before the mash.

I burned off about a gallon of water in an hour. In hindsight, I could have boiled more vigorously too, to get more boil off. Was concerned about boiling more than an hour, based on stuff I have read. Not sure how warranted that is. Can you boil 90 or 120 mins? The advice I read was to jsut see what I got from the kettle and make adjustments next time. Seemed sound.

The beer that went into the fermenter, has a decent enough taste to it.

It was still a good experience for me. I am truly into this BIAB now. Will be more conservative with water estimate, and looking forward to next batch.

 

[Saunassa]

Glad to see your temps held. I wrap a heavy cotton bath towel around my kettle, then a couple comforters. Big plus is tucking them in at bottom under my propane burner to keep the cold air from pot bottom. Starting mash temp is 152 and even with the stir at 20 minute mark I usually only lose a couple degrees in 60 minutes. Thats with a garage temp of 30f