I was really close to making a poll for this thread, but I really want to make this more open ended. I'm wondering how big of an impact you think mash temperature has on the final body of a beer. Has anyone ever done a side-by-side, or brewed the same recipe twice?--Once with a low mash temperature and once with a high mash temperature? I tend to mash around 152F for most of my beers. If I go drier, I'm looking at reducing crystal malt, and adding sugar. If I go maltier, I tend to add crystal or look at a less attenuative yeast. I guess that makes me recipe driven more than process driven. Where does everyone else fall?
I have mashed from 150° to 158°F on different recipes. I usually try to follow temperature specified in a recipe I am trying, then I might bump it up or down on a subsequent attempt, depending on how dry it ended up (or should end up). Curiously, I had a beer once start at 1.094 and finish at 1.008 and still seem to have pretty strong residual sweetness and body. The mash temp for that one was 150°. Given that example, your "recipe driven" vs. "process driven" remark makes me think that ingredients choices matter significantly, too. What kinds of grains, quantity and quality, and also yeast selection and pitch rate are probably all significant factors in the final result. I haven't arrived at any grand overall conclusions, but I have observed enough variability on results that I now work with recipes that I like and try to isolate one variable at a time. This became easier when I started buying base malt in bulk and could pull multiple batches from the same bag of grain and run it through the same mill at the same settings back to back. I now have a pale ale, a wee heavy, and a German Alt that have become "beers I want to drink and enjoy consistently". The work continues soon in 2014.
Upping the mash temp can increase body without adding residual sweetness. The same is not true if you increase the amount of crystal malt in your recipe. The other place mash temp helps if you are trying to hit a color and a certain kind of mouthfeel. Making a rich malty beer from 100% pilsner malt would be difficult without manipulating the mash temp (or a decoction mash possibly...?) While I haven't done a head to head, same recipe diff mash temp, I have definitely found a strong correlation between mouthfeel and mash temp in general.
Why just use one dial when you can use two? Why go to 10 when you can go to 11? I look at it as a matter of granularity. You can achieve a range of the spectrum by tweaking the amount of Crystal, but you can get more specific by playing with both. And like @mattbk said, Crystal adds sweetness. A big, roasty IRS is probably going to need a good helping of Crystal, but if you want a more bitter, semi-sweet cocoa and coffee profile, you may want a Kate Upton body without the Richard Simmons (?)(sure, why not) sweetness.
I missed my mash temp on my last apa, 162 instead of 152. It made beer, but it's off in both mouthfeel. Its carbed well, but feels flat and resinous on the tongue. Iits okay beer, but so strange. I was going to revisit the resinous stout thread to talk about this though. That last stout I brewed was mashed at 155, but I used wlp001 in conjunction with wlp002 and it attenuated down from 1.086, I don't remember fg but I remeber the math came out to 82%. It has body, but I wanted something to coat the glass when I swirl it in my globe. I had another of mine last night and it certainly doesn't do that, but the mouthfeel is close. Instead of changing my mash temp I plan on using 002 exclusively, or maybe irish stout yeast, and bumping my oats up a percent or two, along with adding a hair more crystal and aiming for 1.100 instead of 1.086. I am hoping that may be the magic I need. If not, maybe I will mash it at 160...
mash is huge. now, the difference between 153 F and 155 F, especially on our homebrew systems that may lose 1-2 F over 45-60 min, may be insignificant. it would take a lot to convince me that there's a difference. but mashing at 149 vs 156? for sure. don't know how one can say there isn't. i brew with a lot of brett. if i didn't care about my mash temps, then my partial and all-brett beer would be fermenting until i was shitting out of my nose. well, not literally. but yeah, i care. 149 F and you have a wine-like dry finish. a stout, IMO, should be around 155 F.
It can make a significant difference in attenuation, which affects body. Greg Doss and Kai Troester have studied the affect on attenuation and BrewCipher models it (based on Kai's results). It's worth noting that the Doss and Troester experiments found that lower isn't always more attenuative for single infusion mashes. (It depends on 'lower than what' and 'how much lower.') There's often more than one way to skin a cat. Somewhere in between, for me.
Im a belgian lover- rarely exceed 150, usually 148. I have made a few APA and IPA even still 151, i like it dry. To answer OPs Q I think its quite important, never done an experiment, but I can tell you that I make dry beer and that its mostly cause of low mashing.
I'm in the middle. I use both, but depends on style and what I'm trying to do. I'll mash most of my pales, IPAs and blondes in the 148-150 range. 152-154 for the porters and around 153-156 for stouts and beers I want more body too. Light doesn't always equal lower though. I'm going to brew a sour soon, and I'll need 156-158 and a bunch of crystal and whatnot to give the bugs some food. Bottomline, you've got tools and options. One can be easy and get ya there, the other can fine tune the machine to get it where you really want it. I tend to move around with that logic, depending on what I'm brewing and how well I want it to really come out.
A higher mash temp leaves more dextrins in the wort. Dextrins are unfermentable sugars - but they are completely flavorless. The presence of dextrins will increase your FG, but not your sweetness. That's the theory anyway - in reality, I expect a higher FG may change your PERCEPTION of sweetness - but objectively the sweetness is no different. Fair enough, but as others have said, it's one more dial to control. You're not blindly pitching a packet of yeast into the fermenter are you? You make the selection of strain - your recipe - then ensure you make an active starter scaled to your recipe. This is a process that generally results in better beer. Manipulation of mash temp is the same.
This is all true. But I have a factoid to add, and I'm hoping one of our biochem types will chime in. Mash temp can, I'm fairly certain, also affect the amount of Maltotriose in the wort, and yeasts strains vary in their abilities to effectively break down and use maltotriose. But here's the factoid... Salivary alpha-Amylase has been shown to break down Maltotriose into Maltose and Glucose. What I haven't been able to find out is How Fast this happens. One thing that bothers me is that the temperature in a person's mouth is much lower than the temperatures at which alpha-Amylase is most efficient. But there are people apparently studying the phenomenon, so presumably it's relevant to something that happens in our mouths. All this is a long-winded way of saying that if Maltotriose is being turned into Maltose and Glucose in saliva, there may be some amount of sweetness perceived, even though (surviving) Maltotriose doesn't itself taste sweet. Hopefully one of more of our biochem guys know something about this.
will look into pulling this paper on Monday: http://www.ncbi.nlm.nih.gov/pubmed/11026667 My comment about perception of sweetness was that more body and mouthfeel tend to coat the tongue and mouth more, lead to a longer finish, and allow sweetness in the beer to be more fully perceived. But that's really just theory, I have no data to support this.
