The simple question is: How important is a mash out?
Most of my mash schedules include a mash out, but is it effective? In order to do a mash out, I have to add additional water. Now the water column increases which - I assume - compresses the grain bed. So in that case, is a mash out really doing anything useful?
System: 3 vessel herms. I stopped doing mash outs a while back. I think but I may be incorrect but mashing out denatures enzymes. Someone correct me if that is wrong. I figured that I can do that by taking the mash straight to the BK. Time saver for me.
“On the commercial scale, employing a mashout is important for the purposes of consistency, predictability, and yield.” — Palmer, How to Brew
As it is with many brewing processes, some homebrewers have adopted the method because that’s how commercial brewers brew so that’s how they must brew.
Some say if using a lot of ‘sticky’ grains (i.e. wheat) then a mash out helps with viscosity reducing the chance of a stuck lauter.
Others ignore it altogether under the belief it has no impact on a homebrew scale.
I began using a mash out recently but the reason has nothing to do with enzymes or stuck lauter. I began holding crystal and roast malts to the mash out vorlauf + sparge vorlauf (I do 15 min each now) for a 30 minute total hot steep of those grains.
Mashout is done to denature all the enzymes and limit fermentability.
After the mash is complete, if you can runoff and bring your wort to a boil within an hour, then you are mashing out on the way up to the boil anyway. This will result in a typical, “normal” beer that is not too dry and not too full, not too thin and not too sweet, etc. So then a separate mashout step is completely worthless.
If you’re going to dork around for a few hours, then a mashout is useful if you don’t want super high fermentability, high ABV, low final gravity, thin body. But if you don’t care about those parameters, then again, mashout is not necessary.
I’ve worked at 3 commercial breweries and not one of them bothers doing a mash out. Most commercial breweries are either trying to get the first mash run over into the BK or the last mash empty so the brewer can go home.
A lot of time the mash will raise up to 165 during the sparge anyway. There’s no convenient way to mash out commercially without adding a lot of extra time to the brew day.
+1 – The enzymes probably take longer to denature than 10 minutes anyway. Best just to move on to a boil. No real need to mash out.
With my system its easy to do step mashes so I’ve tested identical recipes with and without a mashout many times. I can’t tell a difference.
20 min. is the minimum time usually cited.
My standard mash is a two step with rests at around 148° and 163°. When I had a RIMS, I added a final rest at 170°. What I noticed is that the wort in the sight glass would be very clear after the 163° rest, but it be absolutely crystal clear after just a few minutes at 170°.
My assumption is that there must have been some final bits of starch that didn’t get converted until that final rest. Whether or not that’s important, I don’t know. Maybe those final bits get converted in the kettle as the wort is coming up to a boil anyway.
Anecdotally, I think there may be some benefits for foam retention. But I’m not positive, and I don’t know what the mechanism would be (glycoprotein formation?).
If I build or buy another recirculating system (and there must be something wrong with me because I’ve already starting planning it out), I’ll be adding that final 170° rest back.
The arguments for mashing out are bunk. By the time you would mash out, nearly all of the starches that are going to be converted have been converted, unless you really screwed up the mash. You’re not “locking in” the wort profile in any meaningful way by mashing out. As for the viscosity argument, on the list of variables that are important to control in brewing, the difference in wort viscosity between 160 degrees vs. 170 degrees is at the very the bottom for me…actually it’s not even on the list. Where I worked, we viewed mashing out as pointless and never did it.
Mashing out is a holdover from the days of under-modified malt, where there were still enough beta-glucan sugars remaining in the grain that could lead to a more viscous mash that might cause problems lautering. Mashing out might thus be useful for a commercial brewery using under-modified malt. At the homebrew level, IMO it’s useless no matter what kind of malt is used.
All fascinating answers and I learned a lot! Thank you all!! It seems I’m spinning my wheels with a mash out as that step does not pay any dividends.
Thanks brewers!
I have an electric BIAB system, and I pull the bag of grains at around 168-170. I don’t do a full rest there, but I do notice that I get 1-2 gravity points on the way up from 162 to 168, which is why I wait until then to pull the bag.
Similar thing here. I have a Foundry and my mash is pretty much a slow ramp from 147F to 172F. I pull my grains between 172F and 175F. I seem to be getting a bit more efficiency, although I think it is more from having a longer mash than the temperature schedule.
Have never done mash outs in 10+ years of brewing, never seen a need to. For me it would be time wasted in my process. As already pointed out, sparging directly from my mash tun at whatever my mash temp is into my kettle that then immediately gets brought to a boil, there is no need for mash out and enzymes get denatured quickly.
I have a single vessel electric BIAB, so raising temps for my system is easy and quick, I feel like I get clearer wort going to the boil, so I employ a mash out.
Have you ever done a comparison with and without on the same recipe using the same bags of grain?
I dont have to capacity to do side by side type stuff like brulosophy, I just notice clearer wort when I recirc at 172 for 10 minutes. It very well could just be the longer recirc that does it, and have nothing to do with the temperature. Either way, part of what makes brewing easy for me is the familiarity with repeating the same process over and over again, so I keep doing it
You can do back to back. That’s what I do in situations like that.
maybe one day, but I also only have one fermenter with temp control.
I have developed (deteriorated?) to a point of having little care about the clarity of the wort going into the boil - I am much more concerned with the beer clarity after primary fermentation and cold crashing/racking/serving. I find that I do not have to fine beyond kettle additions of Brewtan B and Whirlfloc and I get very clear results with amber and pale beers.
I have found little to no correlation, let alone causative effects/speed to clearing between clear wort into the boil and clarity of finished beer. Even so, clear wort is pretty to look at - no denying that.