How much does mash temp really effect mouthfeel?

[cmac62]

I have been brewing for about 4 years now, all grain from the beginning. I have always heard 146-150, for a thinner, more fermentable wort and 150-155 medium body, and anything higher for a thicker, chewy brew. I don't know if my mouth just isn't that sensitive, but I don't notice that much of a difference from 147 to 153. Some of my Scottish ales are definitely thicker, but I also boil them for 90+ minutes. Is it the 156 mash or the long boil that brings the chew to the brew? Inquiring minds would like to know.

 

[TurnipGreen]

You know, I can’t tell a huge difference between five degrees in mash temperatures but I do notice it at ten degrees. Part of that might be ‘cause I’m rarely able to do a side by side taste of the same recipe with different mash temperature. I also prefer my staple beers on the dry and thin side. More often then not when I do mash higher it’s for a higher gravity beer with some sort of simple sugar. I alway wonder if it’s the bringer grain bill or the higher temperatures driving the mouthfeel. Everything I read says it’s the temps. The mash temperature drives the sugar conversion and (in your example) the boil is just driving the gravity.

I have however seen (measured) differences in gravity from a smaller difference in mash temperatures.

 

[hopjunkie26]

When I brew a recipe that I have brewed several times over and don't hit my higher mash temp for one reason or another, I can generally tell that the beer is thinner.

And really, the mouthfeel will be impacted by both the mash temp and length of boil.

 

[day_trippr]

When I brew a recipe that I have brewed several times over and don't hit my higher mash temp for one reason or another, I can generally tell that the beer is thinner.[...]

^That^
And given how fast modern grains convert it could be all over before the temperature makes it to the original goal...

Cheers!

 

[corax]

And given how fast modern grains convert it could be all over before the temperature makes it to the original goal...

Exactly. On top of this is the fairly broad temperature range of activity. Even if you're at a temperature where beta has only 20% of its maximum activity, 20% of a huge activity is still significant activity.

 

[tri_clamp_ninja]

It's more so that mash temp plays a role in attenuation which in turn plays a roll in your final mouth feel. *Generalization* A higher mash temp = lower attenuation = more mouthfeel do to more unfermented sugars remaining. A lower mash temp = higher attenuation = thinner mouthfeel do to less unfermented sugars remaining.

This of course can be altered by a low mash temp using a high percentage of caramel type malts which add long chain non-fermentable proteins that aid in final body and head retention or by mashing high and using less of those types of grains. Also keep in mind that these types of grains all add some fermentables but so minimally that it's pretty much negligible. In a specialty heavy beer the mash temp is more so going to alter the fermentability of your base malt.

With a traditional step-mashed lager, your temperatures and rest periods are very important because these beers are primarily base malt so any body comes from your mash procedure. With most modern craft ales the mash temp, arguably, isn't as important because most of your body and head retention is going to come from heavy specialty malt additions therefore your mash temp is going to be more critical for hitting your FG then building body.

When I first started developing the core beer for the brewery I run I ran several mash tests on our flagship Blonde Ale. I kept all variables the same except I mashed batch 'A' around 148f, batch 'B' around 152f, and batch 'C' around 154f. This beer was 97% 2 row base malt, 1.5% victory malt, and 1.5% carapils malt. All three batches had the same preboil gravity and all three batches had the same post boil/original gravity going to the carboys. All three carboys received the same yeast pitch and were fermented at the same temps for the same number of days (10 days @ 66f, 3 days at 31f, keg + carb). Batch 'A' attenuated to 89%, 'B' to 85%, and 'C' to 81% which resulted in roughly a 0.5% abv difference from 'A' to 'C'. The important part.... all three beers had the same head retention (I timed them with a stop watch), all three beers had the same perceived mouth feel (with several panels of "judges"), and all three beers tasted the same (with several panels of "judges").

So, were they different? Yes!
But, were they really different? Nope.

 

[GPP33]

This is what I would have expected from an experiment like this and what I believe a brulosophy experiment reveled. Mash temp has been scientifically proven to affect the types of sugars formed which will have a direct effect on the FG but it’s only one of many things that affect the perception of mouth feel and most beer drinkers simply aren’t knowledgeable/experienced enough to know or care about a difference that minor. I have a Kolsh that finished at 1.008 and a wit that finished at 1.014, the wit feels thinner to me. Other factors are clearly playing a more pronounced role in this perception, someone with a more refined pallet may be able to detect a higher residual sugar content in the wit, but I’m the one drinking it and I can’t. I’d expect that a mash difference of 148 to 168 would be noticeable but worrying about 150 to 152 is just nonsense IM. That said I obsessively tweak until my strike temp is perfect, our minor OCD tendencies (which I’m sure we all have) are a topic for another thread though.

 

[bleme]

My club did a triangle test a couple months ago with an IPA recipe. One batch was mashed at 150F and the other at 160F. His goal was to make a session IPA that still had the same body. While they were serving temperature nobody could tell the difference between them, even though the one mashed at 160F finished at just 4.5ABV.

On a side note, once the beers warmed up to room temperature I thought one was sweeter than the others and would have changed my vote (to the right one) if I could have.

 

[cmac62]

You know, I can’t tell a huge difference between five degrees in mash temperatures but I do notice it at ten degrees. Part of that might be ‘cause I’m rarely able to do a side by side taste of the same recipe with different mash temperature. I also prefer my staple beers on the dry and thin side. More often then not when I do mash higher it’s for a higher gravity beer with some sort of simple sugar. I alway wonder if it’s the bringer grain bill or the higher temperatures driving the mouthfeel. Everything I read says it’s the temps. The mash temperature drives the sugar conversion and (in your example) the boil is just driving the gravity.

I have however seen (measured) differences in gravity from a smaller difference in mash temperatures.

I use the longer boil time to kettle caramelize the sugars, thus changing them to non-fermentables.

So far the responses are pretty much what I expected. The mash temp definitely produces more or less fermentable wort, but at + or - 5 degrees the change is so minor that most people wont know the difference.

Day tripper, how fast do modern modified malts convert. I always mash at around an hour, but if I could cut time there I would.

 

[ScrewyBrewer]

I once read where the window for hitting a target mash temperature needed to happen within the first 20 minutes.

 

[hopjunkie26]

^^^Sounds about right. I have an eHERMS that I do a constant recirc on and I generally try to ensure the temp is equalized within the first 5-10 minutes of the mash. Usually it is within a minute or so but sometimes it gets away from me if I am not paying attention to my HLT temp.

 

[mabrungard]

I use the longer boil time to kettle caramelize the sugars, thus changing them to non-fermentables.

So far the responses are pretty much what I expected. The mash temp definitely produces more or less fermentable wort, but at + or - 5 degrees the change is so minor that most people wont know the difference.

You're kidding yourself. First of all, a long boil doesn't produce much, if any, caramelization and that doesn't effectively change fermentability. In addition, a long boil can deplete the wort of coagulable nitrogen and that can result in lack of head in the resulting beer. Raw wort has too much coagulable nitrogen and boiling reduces it, but you don't want to go too far.

I tend to agree on the imperceptibility that minor mashing temperature difference makes on the resulting beer. Most drinkers won't pick up the difference. However, the hydrometer is likely to pick up that difference. It just doesn't end up very perceptible to the drinker.

 

[cmac62]

You're kidding yourself. First of all, a long boil doesn't produce much, if any, caramelization and that doesn't effectively change fermentability. In addition, a long boil can deplete the wort of coagulable nitrogen and that can result in lack of head in the resulting beer. Raw wort has too much coagulable nitrogen and boiling reduces it, but you don't want to go too far.

I tend to agree on the imperceptibility that minor mashing temperature difference makes on the resulting beer. Most drinkers won't pick up the difference. However, the hydrometer is likely to pick up that difference. It just doesn't end up very perceptible to the drinker.

Interesting, because it sure changes the color of the wort. I have read that scotch ales would use a very simple malt bill and it is the long boil that produces the non-fermentable sugars that provide the sweetness in the finished beer. I know I have also read about the (something with an M reaction) that converts some of the maltos.

 

[day_trippr]

Maillard reaction, and yes, it's a thing that can happen in the kettle...

Cheers!

 

[RM-MN]

I use the longer boil time to kettle caramelize the sugars, thus changing them to non-fermentables.

So far the responses are pretty much what I expected. The mash temp definitely produces more or less fermentable wort, but at + or - 5 degrees the change is so minor that most people wont know the difference.

Day tripper, how fast do modern modified malts convert. I always mash at around an hour, but if I could cut time there I would.

Very fast. I've experimented with that and found complete conversion in under 5 minutes. However, the deciding factor isn't the conversion, it is the gelatinization of the starch that determines how long you need to mash and that is controlled by how finely you mill the grain.

Now comes the other factor in how long to mash. Regardless of how fine I mill the grain, it seems to take 20 to 30 minutes to extract the flavor from the other grains. I don't recommend doing a mash less than 30 minutes in duration for that reason and then only if you can mill your grains to near flour (cornmeal?) consistency. For that to work you need to be doing BIAB or you will get a stuck mash or sparge or both. Larger grain particles take longer to gelatinize the starch, thus the longer mash.

 

[day_trippr]

^Can't argue with the gist of that^

 

[tri_clamp_ninja]

You're kidding yourself. First of all, a long boil doesn't produce much, if any, caramelization and that doesn't effectively change fermentability. In addition, a long boil can deplete the wort of coagulable nitrogen and that can result in lack of head in the resulting beer. Raw wort has too much coagulable nitrogen and boiling reduces it, but you don't want to go too far.

I tend to agree on the imperceptibility that minor mashing temperature difference makes on the resulting beer. Most drinkers won't pick up the difference. However, the hydrometer is likely to pick up that difference. It just doesn't end up very perceptible to the drinker.

I'll have to agree (as usual) with @mabrungard

For me and my extensive testing,
A long boil, let's say 70+ mins or anything more then the "standard" 60 mins, has only helped in two areas:

1) This really helps to drive out off-flavor precursors in all-grain beers to prevent things like DMS and Diacetyl
2) It is an easy way to get stupid high IBU's and bitterness profiles that aren't boring and/or one dimensional due to having more time to space out hop additions

As a general practice I started boiling all of my all-grain worts for 70 mins (some of them more, like very hoppy beers and very light beers) but this was solely for the reasons I mentioned above. I mainly do this because it has entirely eliminated what minimal off flavors I occasionally had and has slightly increased my shelf stability. From a homebrew standpoint those aren't huge deals but considering I am a professional brewer running a commercial facility it is VERY important to consistently produce my core portfolio without off flavors and to achieve the longest natural shelf life as possible.

 

[MPBeer]

I'm wondering this too. The mash temp definitely affects the fermentabillity of the wort, but I'm not sure if that really leads to bigger mouthfeel. I've heard sweetness = mouthfeel, but I think there are more than that. Because my 1.030~1.035 FG stouts with flaked oats are not as thick as I wish.

 

[tri_clamp_ninja]

I'm wondering this too. The mash temp definitely affects the fermentabillity of the wort, but I'm not sure if that really leads to bigger mouthfeel. I've heard sweetness = mouthfeel, but I think there are more than that. Because my 1.030~1.035 FG stouts with flaked oats are not as thick as I wish.

One of my favorite recipes I've made is an Oatmeal Session stout, starts around 1.040 and ends around 1.010. About 25-30% of the grist is made of a combination of c90, black malt, chocolate malt, carapils, and flaked oats and the remaining 70-75% being 2 row base with the mash being a single infusion between 148-150 held for 60 mins. Most of the time I would do a full volume mash with no sparge. Basically everything about this recipe and SOP (besides it's generous percentage of specialty grains) should lead to a beer that is thin and has little head retention. This beer has so much body that nobody ever believes it is sub 5% abv and the head won't go away, seriously... you'll still have head until your last sip. I developed this recipe years ago before I did the extensive testing of mash temps and it really goes to show how today's modified specialty grains can control much more of the final outcome then your process itself.

 

[stickyfinger]

do a side by side with blind tasting. i would bet you can’t tell the difference between 150 and 165.

 

[Smellyglove]

You're kidding yourself. First of all, a long boil doesn't produce much, if any, caramelization and that doesn't effectively change fermentability. In addition, a long boil can deplete the wort of coagulable nitrogen and that can result in lack of head in the resulting beer. Raw wort has too much coagulable nitrogen and boiling reduces it, but you don't want to go too far.

I tend to agree on the imperceptibility that minor mashing temperature difference makes on the resulting beer. Most drinkers won't pick up the difference. However, the hydrometer is likely to pick up that difference. It just doesn't end up very perceptible to the drinker.

I agree that caramelization doesn't occur in wort-boiling temperatures, you need to go higher. But when it comes to mouthfeel, there's a huge difference. This is due to the Maillard reactions. The beer just gets thicker.

But as far as I've understood it a hard boil can render some of the sugars unfermentable. It shouldn't be because of caramelization since afaik it happens at higher temps. For instance. Two friends of mine has done a single mash, and boiled on their own setup, side by side, right there after the mash, a few times. The one of them which just literally blasts his BK with the burner has always had lower fermentable wort, same yeast, but ferm-temp might wary as they do it at home, but the difference in FG has been huge.

I had the same issue when I first started brewing on my new setup (and went for a hard intense boil, comparing to previous setup). Couldn't find the culprit. I emailed JP and he responded with "turn your heat down", and voila, I started to get my 2 points back.

And, this is not I've tried myself many times. I got bronze in the nationals with my imp stout, it was boiled for five hours. It was thick as oil. One judge said it was not fully fermented, while another said it was "silk smooth", (the two comments I related to the boil time) and had a great head. The head came from me bumping the carbonation in the keg to almost the double of what an imp stout should have (on the paper), because it was so thick so the carbonation didn't come through at normal levels. The carbonation was high, but the percieved carbonation was in the ballpark.

 

[cmac62]

So the Maillard reaction does convert fermentable sugars to unfermentable ones in the kettle, but does this have any significant effect on the mouth feel/body? I believe it would. The more unfermentable sugars the thicker the beer should end up. Right?

 

[tri_clamp_ninja]

So the Maillard reaction does convert fermentable sugars to unfermentable ones in the kettle, but does this have any significant effect on the mouth feel/body? I believe it would. The more unfermentable sugars the thicker the beer should end up. Right?

Well the answer to this is really the same back and forth that has been going on with this thread the entire time:

Yes, your final product would technically have higher viscosity then a more fermentable wort which would equate to a thicker mouthfeel in the finished beer.

However...
Most people would not tell the difference.

So it really comes down to this:
Are we talking about (a) technical numbers on paper or are we talking about (b) the average drinker's perception?

A= Yes, it does have an impact
B= No, most people cannot tell enough of a difference for it to actually "count"

 

[Smellyglove]

So the Maillard reaction does convert fermentable sugars to unfermentable ones in the kettle, but does this have any significant effect on the mouth feel/body? I believe it would. The more unfermentable sugars the thicker the beer should end up. Right?

Huge difference. I have a RIS where I've "always" boiled it for about 5 hours. Last time i did som math to target 60 minute boil time. (I've also done it at three hours and something between 3-5 hrs, but not very often, most often it's been 5 hrs) Very different beers, like completely. The 5 hr boil is smooth as slik and thick as oil, the 60 minute is thinner and not as silk-smooth, but more easy drinking, equally enjoyable, but just different. Here's the kicker. The OG and FG for both (all of the 5hrs boils, comparing to the one 60min) beers were the same.

I can also tell it in Doppelbocks where I've boiled 3 hrs vs 90 minutes, and hefeweizens where I've boiled three, two, one and a half (slightly different) vs 60 minutes. They have all been boiled at the same boil intensity.

Boil intensity matters also a lot also. I can tell difference between hard boil 60 minute and slight boil 60 minute. the slight boil 60 minute has a good full mouthfeel which doesn't come from viscosity, but rather from uncoagulated body-positive proteins, but also some sort of "thinner" feel at the same time, almost like it's drier. Hard boil 60 minute is thicker due to viscosity.

 

[kevin58]

Interesting, because it sure changes the color of the wort. I have read that scotch ales would use a very simple malt bill and it is the long boil that produces the non-fermentable sugars that provide the sweetness in the finished beer....

Brewing logs from Scottish and English brewers from the early 1800's (around 1831 to be exact) to about 1914 tend to show very little difference in boil times between the two countries. In some years actually, the longer boil times were done at English brewers like Truman. One chart I can recall seeing was for Wm. Younger's brewery (from which my avatar comes from) listing brew times between 1831 and 1898 for all of their shilling beers from 60/- to 140/- ....they range from just 1 to 1.25 hours in 1831, stayed pretty close to that time through 1835 when some of the times jumped to 2.25 to 2.5 hours and the longest times were recorded in 1898 when boil times averaged 3 hours.

As for the color, it seems the Scots actually preferred lighter colored ales but when brewers were making the same ale for export where drinkers expected a darker color, they would add coloring at packaging time.

There are a lot of myths and misconceptions about Scottish brewing having more to do with romantic stereotypes rather than actual records.

http://barclayperkins.blogspot.com/search/label/Scotland

 

[mabrungard]

Boiling habits and methods used by pro-brewers started changing in the 70's. Most did boil long and hard up to that time. Then the oil embargo hit and everyone was interested in saving fuel and energy. It was then that the brewing research started reevaluating the needs of the boil.

Virtually all modern German and English brewery equipment manufacturers have implemented measures and equipment that reduce heat stress on wort and evaporation loss. My research on American equipment manufacturers shows that they are far behind when it comes to reducing heat stress and evaporation loss on wort. Most modern equipment manufacturers recommend limiting boiling time to around an hour, although there can be cases where longer boil is warranted.

A long, hard boil can take out too much coagulable nitrogen from the wort and excessive heat stress does make the resulting beer more prone to more rapid oxidation in the package.

 

[MPBeer]

Huge difference. I have a RIS where I've "always" boiled it for about 5 hours. Last time i did som math to target 60 minute boil time. (I've also done it at three hours and something between 3-5 hrs, but not very often, most often it's been 5 hrs) Very different beers, like completely. The 5 hr boil is smooth as slik and thick as oil, the 60 minute is thinner and not as silk-smooth, but more easy drinking, equally enjoyable, but just different. Here's the kicker. The OG and FG for both (all of the 5hrs boils, comparing to the one 60min) beers were the same.

I can also tell it in Doppelbocks where I've boiled 3 hrs vs 90 minutes, and hefeweizens where I've boiled three, two, one and a half (slightly different) vs 60 minutes. They have all been boiled at the same boil intensity.

Boil intensity matters also a lot also. I can tell difference between hard boil 60 minute and slight boil 60 minute. the slight boil 60 minute has a good full mouthfeel which doesn't come from viscosity, but rather from uncoagulated body-positive proteins, but also some sort of "thinner" feel at the same time, almost like it's drier. Hard boil 60 minute is thicker due to viscosity.

I always wondered about this... because I read an exbeeriment on boiling 60 min vs 180 min (http://brulosophy.com/2017/11/13/boil-length-pt-3-60-minutes-vs-180-minutes-exbeeriment-results/) and they said there weren't any difference. However, I heard few brewers (TGB for example) boil their stouts for few hours to get that huge mouthfeel. Would that be just from evaporating water and getting concentrated wort? Or does the long vigorous boiling actually makes any difference?

 

[Smellyglove]

I always wondered about this... because I read an exbeeriment on boiling 60 min vs 180 min (http://brulosophy.com/2017/11/13/boil-length-pt-3-60-minutes-vs-180-minutes-exbeeriment-results/) and they said there weren't any difference. However, I heard few brewers (TGB for example) boil their stouts for few hours to get that huge mouthfeel. Would that be just from evaporating water and getting concentrated wort? Or does the long vigorous boiling actually makes any difference?

In my case OG/FG was the same, and also volume, so the end wort was equally concentrated.

 

[tripeland]

Boiling habits and methods used by pro-brewers started changing in the 70's. Most did boil long and hard up to that time. Then the oil embargo hit and everyone was interested in saving fuel and energy. It was then that the brewing research started reevaluating the needs of the boil.

Virtually all modern German and English brewery equipment manufacturers have implemented measures and equipment that reduce heat stress on wort and evaporation loss. My research on American equipment manufacturers shows that they are far behind when it comes to reducing heat stress and evaporation loss on wort. Most modern equipment manufacturers recommend limiting boiling time to around an hour, although there can be cases where longer boil is warranted.

A long, hard boil can take out too much coagulable nitrogen from the wort and excessive heat stress does make the resulting beer more prone to more rapid oxidation in the package.

Does the 1 hour boil time apply for wort with a large % of pilsner malt? Or is the 90 min boil warranted in that case

 

[mabrungard]

Does the 1 hour boil time apply for wort with a large % of pilsner malt? Or is the 90 min boil warranted in that case

I can get by with only an hour for beers with large pils content, but my elevation is only 750 ft. Brewers at significantly higher elevation, may have to increase the duration of their boil in order to convert enough SMM to DMS to prevent DMS problems at the end of the boil.

My suggestion would be to start dialing back boil duration for those high pils worts and see when DMS becomes a problem for your beer. In the case of low pils content, there isn't any need to perform an extended boil duration...except if you want your beer to have those aged and melaniodin-rich notes (think barleywine and old ale).

 

[cmac62]

I may have to do my own exbeeriment, two batches of a Scottish 80, one boiled for an hour and one boiled for three to see if there is a difference with everything else being the same.

 

[mabrungard]

I may have to do my own exbeeriment, two batches of a Scottish 80, one boiled for an hour and one boiled for three to see if there is a difference with everything else being the same.

So you'll top off the wort from the 3 hr boil to bring the gravities for the batches to the same level?

 

[cmac62]

right

 

[cmac62]

I was thinking about doing a 10 gal batch and lauter off half at 60 into a second kettle and chill normally, then when the second half has boiled 180, adjust for gravity and chill. Ferment both with WL Edinburgh (can't remember the #).

 

[MPBeer]

I was thinking about doing a 10 gal batch and lauter off half at 60 into a second kettle and chill normally, then when the second half has boiled 180, adjust for gravity and chill. Ferment both with WL Edinburgh (can't remember the #).

Please let us know what you get from your exbeeriment!

 

[cloudybrewer]

I was thinking about doing a 10 gal batch and lauter off half at 60 into a second kettle and chill normally, then when the second half has boiled 180, adjust for gravity and chill. Ferment both with WL Edinburgh (can't remember the #).

The half that gets the longer boil will have higher IBUs, right? I know hop utilization falls off after about 90 minutes or something, so it might not make a big difference in a low IBU beer, but for an IPA it might change it noticably, correct? Might be something to think about.

 

[LittleRiver]

...A long, hard boil can take out too much coagulable nitrogen from the wort and excessive heat stress does make the resulting beer more prone to more rapid oxidation in the package.

Martin, what do you mean exactly by "heat stress"?

I realize that may sound like I'm challenging you, but that's not at all where I'm coming from. I've read about the chemical changes that occur during Maillard reactions, and found that fascinating. If there's more I can learn about the effects of heat, then I'm eager to learn from someone who knows more about it than I do. If "heat stress" is just a general term, and it's not really feasible to explain it a forum like this, then that's cool too.

BTW, I've learned a lot from your posts over the past year. Thanks for that!

 

[brewgar]

@river Thank you for your cogent and lucid post(s). I always get good takeaway from your posts.

 

[Smellyglove]

I may have to do my own exbeeriment, two batches of a Scottish 80, one boiled for an hour and one boiled for three to see if there is a difference with everything else being the same.

To make it as "correct" as possible I believe you should not top it up, but start the boil with the correct amount of water to boil for three hours. I'm getting quite different results with beers which are topped up (mashed to a higher strength), than the same recipe which are not topped up. There is most probably different factors in play than just the topping up, but if I were you I'd try to eliminate that topping-up factor. An initial stronger wort will yield more maillard-products.

 

[mabrungard]

One of the primary manifestations of heat stress, is the production of thiobarbituric acid (TBA). There are other compounds produced with extended boiling, but TBA has been shown to be the compound that can be most directly linked with the degradation of beer and the perception of staling.