January 30, 2016 - 1:36pm
milk - to heat or not to heat?
Simple question here. If you use milk in yeast breads, which I do, do you need to heat treat it? I recall being told that you have to raise the temperature of the milk to near the boiling point to remove enzymes that interfere with the yeast action. Of course, once you do that heating, you have to cool the stuff off, and it becomes a timely process. Now, store-bought milk is pasteurized, which involves getting the stuff pretty hot, if not quite near the boiling point. So, it's a do-you or don't-you question. Will the quality of the bread suffer if the milk that is used in it is not heat-treated? I've always done it, but I'm becoming skeptical about the need.
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I have done it both ways and see no discernible difference so I opt out.
I have also read that heating now-a-days is unnecessary due to pasteurization, in fact, most of the milk available where I live is ultra-pasturized. If you live in a country where this is not done then it makes sense.
If you have old cookbooks on hand, they require boiling the milk because milk wasn't treated the way it is now…or so say my sources.
As with most things involving baking - try it out in your own kitchen and see if you notice an appreciable difference in the breads you bake. Nothing better than first hand experience :)
Have Fun,
Janet
Yes, thank you. When I'm in a rush, I don't heat the milk, and things seem to work fine, but I'm reminded of the once-revered (it would seem) edict about heat-treating the milk used for yeast breads. I suspect that to the extent heating is necessary, the pasteurization in modern milk suffices. To that extent, it's just an old wives tale, which may well have been valid for very old wives, who didn't use pasteurized milk.
Now there is little bacterial risk in eating bread made with unpasteurized milk, as bread itself is pasteurized when baked. So where did this edict originally come from? Are there in fact enzymes in raw milk that hurt the yeast? Can bacteria in raw milk hurt the yeast? What's in the raw milk isn't going to hurt anyone eating the bread, so it must be that what's in the raw milk has to be able to hurt the bread itself.
It isn't a concern about the milk hurting the yeast. It is the protein in the milk that weakens the gluten in flour and therefore inhibits the rising of the dough to its fullest extent. By heating milk, the protein is deactivated.
Back in the day when pasteurization wasn't common some smart old farm wife figured out how to get better results via boiling milk. The practice, because it did work, soon found its way into many a kitchen and the breads that were baked with the raw milk and whole grains came out loftier and softer as a result and I am sure their families were all much happier. :)
As stated above, it isn't necessary when using pasteurized milk so you shouldn't notice any difference in the height of your loaves as a result of not scalding.
.
Ahh. Thank you. That's exactly what I wanted to know. But now that research it, I see some disagreement. Many say that the whey protein does this weakening of the gluten, but at least one other source says that it is some bacteria in milk that does it. I'll believe the former.
At least one semi-authoritative source says that even in this day and age milk scalding is important for baked goods because it is assumed that those whey proteins are still active.
http://www.finecooking.com/item/64828/why-scalding-is-still-important
In the definition of "scalding", BTW, temperatures are quoted that are WAY below that required for pasteurization.
So it sounds like yours is the right answer, but there sure is a lot of misinformation running around!
...temperatures are quoted that are WAY below that required for pasteurization.
Scalding of milk takes place at 82°C; pasteurisation at 71.7°C. So pasteurised milk has not been scalded and the enzymes are still active.
That's very interesting. Indeed, "scalding" is defined as 82C in "Joy of Cooking", and that's hotter than most pasteurization processes. And indeed, now that I research it further, it would seem that there is evidence that at least the protease enzyme in milk (which I believe may be that contributed by whey) is NOT destroyed by pasteurization.
http://agris.fao.org/agris-search/search.do?recordID=IR9100289
In fact, that reference suggests that even scalding won't quite do the job.
I'd really like to see some solid research evidence about this. I'm reluctant to rely on cookbooks for my biochemistry. I gather that protease is a enzyme to help digest gluten, and you'd really like that digestion to happen in your stomach rather than in your bread.
I guess the question is still open. Do professional bakers scald their pasteurized milk before baking bread with it?
because they stimulate me to dig further to find my own answers.
First stop, Wikipedia to get a general idea of modern pasteurization:
Process
Older pasteurization methods used temperatures below boiling, since at very high temperatures, micelles of the milk protein casein irreversibly aggregate, or curdle. Newer methods use higher temperature, but shorten the time. Among the pasteurization methods listed below, the two main types of pasteurization used today are high-temperature, short-time (HTST, also known as "flash") and extended shelf life (ESL):
Pasteurization methods are usually standardized and controlled by national food safety agencies (such as the USDA in the United States and the Food Standards Agency in the United Kingdom). These agencies require that milk be HTST pasteurized to qualify for the pasteurized label. Dairy product standards differ, depending on fat content and intended usage. For example, pasteurization standards for cream differ from standards for fluid milk, and standards for pasteurizing cheese are designed to preserve the enzyme phosphatase, which aids cutting. In Canada, all milk produced at a processor and intended for consumption must be pasteurized, which legally requires that it be heated to at least 72 °C for at least 16 seconds,[32] then cooling it to 4 °C to ensure any harmful bacteria are destroyed. The UK Dairy Products Hygiene Regulations 1995 requires that milk be heat treated for 15 seconds at 71.7 °C or other effective time/temperature combination.[33]
EfficiencyThe HTST pasteurization standard was designed to achieve a five-log reduction, killing 99.999% of the number of viable micro-organisms in milk.[35] This is considered adequate for destroying almost all yeasts, molds, and common spoilage bacteria and also to ensure adequate destruction of common pathogenic, heat-resistant organisms (including Mycobacterium tuberculosis, which causes tuberculosis, but not Coxiella burnetii which causes Q fever).[35] As a precaution, modern equipment tests and identifies bacteria in milk being processed. HTST pasteurization processes must be designed so the milk is heated evenly, and no part of the milk is subject to a shorter time or a lower temperature.
Even pasteurization without quality control can be effective, though this is generally not permitted for human consumption; a study of farms feeding calves on pasteurized waste milk using a mixture of pasteurization technologies (none of which were routinely monitored for performance) found the resulting pasteurized milk to meet safety requirements at least 92% of the time.[36]
An effect of the heating of pasteurization is that some vitamin, mineral, and beneficial (or probiotic) bacteria is lost. Soluble calcium and phosphorus levels decrease by 5%, thiamine (vitamin B1) and vitamin B12(cobalamin) levels by 10%, and vitamin C levels by 20%.[21][37] These losses are not significant nutritionally.[38]
From these entries, I confirmed for myself that the industry philosophy behind pasteurization is to enhance the safety and shelf-life of milk by elimination of foreign microbes, while retaining as much of the other properties of the milk as possible.
My next stop was an interesting Google hit related to a patent application for Patent EP0021179A2:
The application document is extremely lengthy and much of the science discussed is beyond the scope of this query, so I elected not to cut and paste it here. I'll try to summarize the salient points as best I can, but if you Google the patent number above, you should be able to read the whole thing should you choose.
The basic premise of the authors is that consumers choose baked goods in a store based on softness and interpret firmness as a sign of being stale (the good ol' "squeeze" test - we've all done it). The authors state that the increasing firmness of bread as it becomes stale is the result of crystallization of gelatinized starch. Their solution for maintaining product acceptability was the addition of alpha-amylase isolated from bacterial cultures, which is supposed to break up the starch polymers and thereby limit the amount of crystallization that would occur. However, they mention that previous attempts to do this were unsuccessful due to the presence of proteases in the enzyme mixture that made the bread tacky or gummy. The invention for which the patent application was written is a process to inactivate the protease while leaving the amylase intact.
The experiments that they detail in the subsequent paragraphs go over many attempts to inactivate the protease by varying pH, buffer solutions, and temperature. The take-away point I got from this was that they were able in most cases to achieve total inactivation of protease at 72 °C between 15 and 30 minutes.
My conclusion from putting these two bits of information together: from the Wikipedia article we see that milk that is labeled "pasteurized," meaning with the HTST method, is held at 72 °C for 15 seconds; while the experimenters in the patent application found it took at least 15 minutes at 72 °C to inactivate the protease (depending on pH and buffer solution used). So it would seem that pasteurization alone does not inactivate protease, making scalding of the milk appear to be necessary.
As for whether professional bakers scald their milk, I'm almost certain that Peter Reinhart (a professional baker) scalds the milk in a recipe in one of his books. I've read almost all of them, but I apologize for not being able to remember which title contained that specific recipe. His books are obviously aimed at home bakers, not professionals, but take his recommendation for what you will.
On a different note (albeit a not entirely unrelated one):
The findings of the authors of the patent application gave me an "ah-hah moment," if my supposition is correct: They mention in one of their discussions of pH control that protease is rendered inactive at a pH lower than 5 (in their experiment they were attempting to keep the pH at 7). So, I looked a little further and found that sourdough has an average pH of 4 to 4.5. Plus, the Lactobacillus sanfranciscens in the culture has a measurable quantity of alpha-amylase. This all leads me to believe that the starch-busting amylase (preventing the crystallization that causes staling) and the protease-killing pH of sourdough is what makes sourdough breads last longer than breads made with commercial yeast.
I'm certain that if my guess is right there is probably already a scholarly paper stating that exact thing, but I just haven't come across it yet. If our resident microbiologist DebraWink, or the ever-well-read Dabrownman, or any other FreshLoafian, can confirm my hypothesis, or at least point me toward such a paper, I would be most grateful.
Thanks!
--Mike
I love milk... Great stuff.
When I was a teen/early 20's (30-40 years back) I worked for a dairy in the bottling plant. It was just a small dairy. We pasteurised the milk and the machine took 1 minute 15 seconds for the milk to pass through. I knew this as we'd heat it up with water, then when we flipped the milk inlet valve, we then had the flip the outlet valve from re-circulate to holding tank 1'15" later... I don't recall the exact temperature it was heated too, but I was under the impression it was only 35-40°C. So it went through the heat exchanger then through a holding loop - that took just under a minute, then back into the other half of the heat exchanger where it was chilled to 4C in 4 seconds. I was told then that it was the chilling that was doing the job after the beasties got nice and relaxed. However I could be very wrong about the temperature.
One dairy local to me tank pasteurises their milk - they heat it up, wait then pump it through a chiller. And another supplies us with raw milk - which is the best.
There are some curious traditions about milk though - my wife was in India last year and did some cookery over there - one tradition is boiling the milk 5 times before making tea - was that something to do with making sure the milk was sterile, or did it really affect the milk? Hard to know - we tried here to see if it made a difference - and couldn't tell.
Homogenised milk is something I'm wary of - but again, I'm lucky where I live in that I can get it without that process. So the cream floats to the top - not really an issue.
Cravendale is the trade name of the ESL milk here (or at least one trade name that I'm aware of) I'm avoiding it like homogenised milk. Who knows.
For breads I make with milk - it comes from the fridge, occasionally via the microwave to take the chill off it and then into the mix.
-Gordon
I think you're overwhelming yourself with information.
Enzymes fulfil a specific function and they can be found where they perform these functions. There are numerous types of protease enzymes each doing it's specific job, each with optimum working parameters, like pH etc.
Like Janet said above it's the whey-protein that is the "problem". Since most proteins are denatured at 70C using pasteurised milk doesn't require further scalding.
I never heat treat mine, havent died yet :)
Hmmm. Good inputs all around. But we still have a problem here. Let's be clear about the purpose of pasteurization. It isn't about denaturing enzymes, it's about sterilization. In fact, as I said, pasteurization of milk is completely unnecessary for making bread because the baking of the bread effectively sterilizes it. Bread is abundantly sterilized in the oven.
FWIW, it's also clear that "scalding" involves more heat than pasteurization.
That being said, the issue is what it takes to denature the enzymes that interfere with the gluten. To those of us who use high gluten bread flour, it seems a waste to add protease to that flour that makes that gluten less effective.
So yes, it comes down to some biochemical expertise, which hasn't obviously weighed in here yet. To the extent that milk glutease is a problem for bread, specifically what heat treatment of milk is necessary to remove it? This HAS to be well understood in the research literature. Again, I'm reluctant to derive biochemical conclusions from cookbooks, because cookbooks are full of we-do-it-because-we've-aways-done-it kind of stuff.
Of course, the whole question may indeed be irrelevant as I've heard a number of people say that they've used milk that hasn't been scalded, and never had a problem. Go figure. Indeed, if I understand him correctly, Gordon seems to be saying that non-scalded and non-pasteurized milk actually works fine.
...Exploring the Fundamentals of Baking Science by Paula Figoni
Paula Figoni is a food scientist and associate professor at the International Baking and Pastry Institute in the College of Culinary Arts at Johnson & Wales University in Providence, Rhode Island. How Baking Works was written as a text book for use by students at the institute. In chapter seven, Gluten, the following can be found under the heading "Milk":
"Fluid milk, above all else, is a source of water. In fact, it is primarily water—about 85–89 percent water. This means that any time milk is added to baked goods, water, which is necessary for gluten development, is also being added.
Fluid milk also contains glutathione, the reducing agent that softens dough. This becomes important in the production of yeast-raised baked goods, where the effects become noticeable during fermentation. If glutathione is not first destroyed, bread dough softens and becomes slack, and oven spring decreases. The result is lower loaf volume and coarser texture.
Heat destroys glutathione. Pasteurization, a heat process applied to essentially all milk sold in North America, is not enough heat to inactivate it. This is why bakers typically scald fluid milk before using it in yeast doughs. To scald milk, heat it in a saucepan until it reaches a simmer (180ºF; 82ºC), then cool.
Likewise, not all dry milk solids (DMS) have been exposed to sufficient heat to destroy the protein. Only DMS labeled as high-heat have been heated sufficiently. The milk used in high-heat DMS has been held at 190ºF (88ºC) for 30 minutes prior to drying. High-heat DMS are the only DMS used in yeast doughs. They are also perfectly acceptable for use in other baked goods."
OK, we may be converging. First of all, glutathione IS a glutamic protease. So we're talking about the same things here. I see that it should be noted that glutathione is also present in flour, and even in active dry yeast, so it's not entirely avoidable. I understand that buttermilk and yogurt don't have these proteases. The protein is deactivated in those. Not clear if that's because of applied heat or the bacterial action.
What this all smells like is that real scalding of milk will help improve dough structure some, but it doesn't appear to be a big deal. I regard scalding of milk as somewhat of a PIA, so unless one is going to scald in bulk, and keep it around for baking, it just complicates bread baking. When I'm in my milk-scalding mode, I take the volume of milk I need, bring it to a brief boil in the microwave, and then cool quickly with ice cubes (leading to a measured dilution milk and water). As in, 2 cups of hot milk, with added ice to raise the liquid level to 3 cups gives a useful cool dilution. If I want to use undiluted milk, it's going to take a lot longer, just to allow for cooling.
I think milk contributes to the taste and very much to the nutrient value of the bread. Good point about "high-heat" dry milk. But it is kinda pricey for the small-scale user. I now understand that this high-heat dry milk is standard for professional bakers, because it's easy to store, and quick to use.
Thanks for that. I'd been trying to find that exact piece of information but hadn't got very far. I would like to find out why, but discovering that they don't need scalding is a start.
I use a mixture of water, milk, yoghurt and a little honey in my bread making and I start by heating them in a saucepan with a thermometer set to sound when the mixture reached 90°C.
While the fluids are heating I measure out my other ingredients, which usually include one or more of einkorn, emmer, spelt and khorosan. It's because these flours need all the help they can get when it comes to gluten development that I always scald milk products and do all the other little things I've read which help in that department. Each may add only a mite to the final result but, combined, I think they're part of the reason I'm turning out good bread.
Once the fluids have reached temperature, the saucepan goes into cold water in the sink for a few minute or so of swirling and standing before the fluids are added to the flour mixture. They don't have to get cold, or even cool, because adding them to the flour cools them and they'll cool even further during the several hours the dough gets to autolyse. And now I know the yoghurt doesn't need scalding, I can cool the liquid a bit more by adding the yoghurt straight from the fridge. No pain and, for me, a worthwhile step in my bread making process.
If you're using milk with high-protein flours made from modern wheat in a lean dough and you don't have any problem getting good gluten development, then you probably don't need to scald the milk. However, if it isn't a bother, doing so isn't likely to cause you any problems and it may prove beneficial.
I don't believe scalding milk is necessary. I haven't observed any discernible difference.
Glutathione (GSH) is not a protease. It's a reducing agent. It relaxes gluten. As you noted glutathione is present in flour, this is why gluten is relaxed after an autolyse. When oxygen is incorporated during kneading glutathione is oxidised to glutathione disulfide (GSSG), strengthening gluten.
Well, that's true. You can cool the milk after scalding if you want to run a big puddle of water in the sink. I'm surprised you use a thermometer for scalding. It's easier just to barely bring it to a boil. Unless you're at altitude, that will work. And that's right that you don't want the milk to get cold after scalding, because any warmth you can add to the mix is a benefit, as long as you don't overheat. But it's simpler if you don't have to heat the milk at al. No pot, no sink, no thermometer, no waiting.
Now, scalding makes sense if you're making bread with low-gluten (perhaps whole wheat or rye) flour. You need all the gluten action you can get. For basic white bread (I do add some bran, though) with bread flour, I don't believe unscalded milk causes any trouble, though I've mostly taken the time to scald it. This thread is where I'm just calling that into question.
The feedback here has been very good. There are good biochemical reasons to scald milk IF you have problems with gluten development. Probably not if you don't. I think that's the lesson. FWIW, my basic white bread uses 50/50 milk/water. If I used 100% milk, scalding might end up being necessary.
I use it so that I can get on with doing other things without having to keep watching the pan. It's warning me that the fluids are about to boil, not that the milk's scalded. It can save an awful lot of mess and prevent the loss of measured fluids.
"No pot, no sink, no thermometer, no waiting."
No problem. To me.
I guess it's simpler for me. I put 2.0 cups of refrigerator-cold milk in a four cup measuring glass. Stick it in the microwave for 4.5 minutes. At that time, it just starts to boil, and it's done. Every time. I don't need any warning that it's about to boil, and there is never any mess or loss of measured fluids. Heating milk on the stove is another matter. You don't have a clue when it's going to be done. So I guess in that case, a thermometer might be handy if you don't want to keep watching it closely.
dlassiter,
Thanks for starting this thread. An abundance of info has followed. Much of it yet, over my head.
Every two weeks or so I brew up some yogurt and kefir and this weekend, for the first time recently, I did so without scalding the milk. I will let you know how it turns out, long term (in a week or two).
If you can eye brain 180F, that is great, but I think there is no shame in using a thermometer.
Cooling in a puddle isn't much effort either, I find.
I'm not sure what to make of 'No pot, no sink, no thermometer, no waiting'; but I would say that neither is easier nor more complex, nor inherently better. Unless, washing out a pot or filling, then draining a sink puts it over the top.
Can someone please define for this poor old ingorant SOB, WTF, FWIW means?
Anyway, I do appreciate the thread.
dobie
Fair skepticism. But as to eyeballing that's easy. It starts bubbling when it's well over 180F. Is there some problem with bringing the milk to the boiling point? You need to wash your thermometer and your pot, and it takes a minute or two (at least in my sink), to put an inch or so of water in it to render it cool. Why waste water? But true, we're just talking minutes.
FWIW = "For what it's worth", FWIW.
I'm in no position to argue whether glutathione is a protease. My apologies if that isn't right. The issue is how to prevent the "stuff" in milk that allegedly screws up the gluten in flour from screwing up the gluten in the flour.
Another vote against the need for scalding milk.
dlassiter;
Damn, and I knew that. Just a brain fart. Thank you for the explaination.
As to the eyeballing, as I've heard it, once you see the little bubbles starting on the outside of the pot, that should be about 180F with milk, and a proper scald.
I'm not tying to be a dick, but apparently sometimes I can't help but being so. Regarding the pots, water, thermometer and etc, whatever works, works. I have no argument. I should have been clearer.
Regarding 'glutathione is a protease' this is (again) over my head and quite honestly, why I am auditing this thread.
So, I thank you and I will step out of the way, so the real conversation can continue.
dobie
Um, no. The bubbles come out of the milk when it's boiling, at (as it turns out for milk at sea level) 212.3F. When you see the bubbles on the milk, you know for sure it is OVER 180F, which seems to me to be a perfectly adequate scald. Though I fear that someone will tell me that one can "over-scald" milk.
Also, yes, I'm pretty finicky when it comes to expending effort on bread. I guess I should apologize for that. I want it to take as little hands-on time as possible. Washing pots, thermometers, and running lots of water counts as expended effort, as does scalding milk in general.
dlassiter,
First, no offense intended, no offense taken. We're good.
I understand minimalizing effort. Truly. Altho, I generally worry more about that once I'm refining my process down, but no contradiction, really.
As to whether you can 'over scald' milk, I don't know. All I can say is that I do put a thermometer to it to 180F and call it quits after that. At that point, it is not truly boiling, but more like just the tiny bubbles appearing at the outer edges of the pot, much as I've heard others (who do it by 'eyeball') say should occur. But, other than by my thermometer, what do I know? Not much, really.
Regardless, the whole denaturing of the enzymes is a very interesting concept. I initially would have thought it accomplished by pasturization, but apparently not (and believably so).
Which sort of begs another point, and I know I am going a little off topic here, but hopefully not too much. I have recently found out in various sous-vide experiments, that to bring (let's say chicken) to a 'safe' point, it is not just dependent on temperature, but about the time at a given temperature as well. The lower the temperature, the longer the time. Apparently, just as safe. So chicken can be safe at no more than 140F, given the right time held at that temp. I believe pasturization of milk to be much the same.
Ultra pasturizing of milk is done at a higher heat, albeit a briefer time. Also, many different temp/time ratios can accomplish the same degree of pasturization. I'm thinking (and I believe this has already been addressed) that ultra pasturized milk might be enzyme neutral (for lack of a better phrase). Not sure tho. There is a lot of verbage that I need to re-read.
From what I'm gathering in this discussion, time to temp does not significantly effect the enzymes. For enzymes, temperature seems to be paramount. I could be wrong, and maybe all the evidence is not yet in. But, we'll see.
Anyway, I appreciate the fascination and I am whole heartedly following the conversation. FWIW (chuckle, chuckle).
dobie
or yogurt. I want to make sire everything is dead in there before introduce a culture to the mix.
Protease and amylase b denature at around 140 F and amylase a at 170 F. Some brewers have mash holds at 140 F to allow amylase b to do its work in breaking down starches and to allow protease to work on the husks of the malt which makes straining out the mash easier later if you want to get a clear brew. Then there is a hold at about 157 F or so to finish killing off the amylase b and protease but allowing amylase a to finish breaking down the starch. This gives you the most sugar to ferment into alcohol and give a different favor to the finished beer.
Many brewers have no intention of getting a clear brew and are lazy like many bakers and they skip the first mash hold temperature and couldn't care less and make some fine beer anyway.
Don't know what this whey protein / enzyme is or at what temperature it is denatured but experience tells me you don't have to worry about it in the real world any more than you have to worry about protease breaking down your gluten and turning your dough into goo. If you are using any milk sold in grocery stores include NFDMP, you don't have to worry about any enzymes in the milk breaking down your gluten. I just doesn't happen in the real world. Now if you autolyse with milk for 3 days at room temperature and then retard a non SD bread for 2 weeks in the fridge that has a lot of sugar in it - who knows - but they bread you would make would be stupid bad to begin with.
..
So no worries and like the lazy brewer you can just skip the scalding of milk and make great bread anyway.
Happy baking with no scalding
dbm
So, cheese also. Are there no limits to your pursuits?
All I can say is that I have always scalded milk to 180-185F for cheese, yogurt and kefir.
However, yesterday (in regards to this discussion) I did not, just to see the effect. So far, every thing looks normal, but let's talk later in the week.
As to brewing, etc, I'm only taking notes.
dobie
one contaminated culture that pops up to mess up the result. When making cheese, yogurt and kefir, it is always best to kill everything off before introducing the culture you want to end up with so you never, ever have a failure.
You can make great bread without scalding though.
dbm
I understand.
Cheese, yogurt, kefir, best to kill all. My usually practice. This is just a test (no cheese tho).
dobie.
especially cheese - even great cheese. For those of us in the cheese business, both making and cutting of cheese made by others, you try to not to kill people. Dying of listeria is a horrible death and if you cause it then you should do a very long time in prison and have all of your possessions confiscated to pay the grieving. I used to run a few of the cleanest cheese operations in this country and listeria was was what kept me up at night.
Don't make things with milk that hasn't been pasteurized if you want to sleep at night - it just isn't worth it.
Well, you can eat bread made with milk that wasn't pasteurized, and sleep well at night. As to making bread with unpasteurized milk, I suppose you can get listeria on your hands while kneading your dough, and die an ugly death. They won't confiscate your possessions, though.
new here and to more serious bread making, but I am a trained chef for too many years.
As for the scalding of milk, I have become obsessed with this question and my conclusion is : YES it makes a difference. Pasteurization ( regular ) does NOT reach the threshold to modify, inactivate, kill or whatever term you choose the offending enzymes. Scalding DOES. It is a scientific open and shut case.
Also the scalding of the milk has an effect on the flour more than the yeast.
NOW whether this makes a noticeable difference is largely a subjective matter. I made a cheese loaf recently and for no particular reason, scalded the milk. I noticed the bread was, in my opinion better. Then trying to figure out why, I realised that scalding was the only variable. As a chef of many years, consistency is not a major issue for me.
So I would summarise by saying, YES scalding makes a difference and if you think the difference is worth the extra 3 minutes effort is up to the individual.
It also seems to me that if you are here on this forum, pursuing the ultimate loaf, why would you cut corners ?
The ultimate test for you is to try both methods, BUT be righteous and genuinely scald the milk. I actually bring milk to the boil and rescue the pot just before it goes all over my stove. I do that as the first thing so that by the time I am set up to use it, the milk has cooled down.
Being a big boy, I do not get excited or stressed about cleaning one more pot !