Using a single infusion approach with a modified cooler mash tun (i.e., no direct heat), what are risks and ramifications of starting my mash at lunch time and coming back 5 hours later to sparge and collect wort? I'll be making a pale ale with an infusion temp of 150. Mash temps generally hold for my usual 1-hr mash.
As long as your mash temp and mash pH is correct, I can't think of any reason why you would have a problems. I believe one of the regular posters in this forum does an overnight mash because of time constraints with no ill effects.
The longer the mash, the more fermentable the wort. But from the data I've seen, it seems to typically level off at around two hours. My assumption is that the enzymes just don't typically survive longer than that.
I typically go do errands during the mash. Many times I have been 2 hrs before getting back. I have never seen any measurable difference in the wort.
I did that a couple of weeks back as well. It also feels like your brew day is shorter by splitting the time and doing something else.
Since the temps will drop some over this time, do you think I should compensate by starting 4 degrees higher? Either way, I'm not too worried. It will make beer. Just like to have a plan going into it.
I've done overnight mashes and it hasn't saved me a minute of time. I find myself waiting on sparge water to heat up in the same way that I would if I were to start heating my sparge water at the end of my 60 minute mash. If this is how you have to split your day up to get a brew in, that's ok, but not for the sake of saving time. Yes. As you say you'll still make beer and maybe lose a touch of efficiency. I double batch sparge and I pour the first half of my sparge water in boiling hot. It gets the grainbed up to 170. It's easy to calculate the temp for the second half that way.
Actually, I would guess it takes a little more time, as normally I'd be heating the sparge water during the mash. But starting when I get home at the end of the day runs the risk of falling asleep during the boil and waking up to smell of burnt hops and caramelly goo.
Probably not a bad rule of thumb. But I wouldn't do it because I expected the temperature to drop over time. I'd do it to offset the additional fermentability that would have otherwise been caused by the longer mash.
I would guess that most of the conversion is done in the first half hour or so. I actually would be a degree maybe 2 high but would not go 4 degrees. The fermentability of your wort may be closer to your starting temperature. Again I have no real numbers to verify that, but have hit my fg numbers pretty well with 2 hr mash's. I do BIAB if anyone thinks that may be different.
True statement. I'd add though that maximum fermentability is not the same as full conversion. The enzymes keep chomping away long after all the starch has been initially been converted to sugars/unfermentable dextrins, until they denature. I think you might be surprised if you compared the fermentability results of a 30 minute mash with a 2 hour mash. Just curious...when you say you hit your FG numbers pretty well with a 2 hour mash, what was the expected FG based on?
I overnight mash far more often than not, and the yeast does what I expect it to. I do start the mash 2-4 degrees F higher than if I was just going for a 60min mash, but I don't sweat it that much. It's a hobby, not a job, to me at least. Very true, but, for me at least, getting my strike water up to temp, and measuring out sparge water happens when I'm unwinding before bed, so it's a pretty passive way to go about it. I do a thin decoction (for lack of a better term) to get to mash out temps, and start heating up sparge water at the same time(I also double batch sparge), first thing in the morning. Basically, I roll out of bed, turn on the coffee, start heating up the sparge water, and collect a couple gallons of wort to boil for mash out. I also start heating my first runnings on med-low, turn up the a bit after collecting the second, and then crank it after the third so that it doesn't take forever for the whole shebang too long to come to a boil.
I wasn't trying to imply it was faster that is why I said it "feels" like it is faster, but I know it is not.
It is calculated by the brew software that takes the OG and uses the manufacturer's average attenuation number. Not a good number to determine much, but I assume if I was getting a highly fermentable wort I would see any major problem. I am not sure I am right, but I always assumed once the starch was broken enzymatically that the enzyme would not break it down further. Funny part is I am a biochemist by trade and never got to the detail of the actual substrates and products.
A BA (I can’t recall the name right now) posted the below video link which discusses starch conversion. Bobby mentions that if you mash low (e.g., 147°F) you need to mash longer (90-120 minutes) to permit the Beta-Amylase to produce a more fermentable wort (around 14:00). If you mash higher (e.g., 160°F), Beta-Amylase is closer to it’s denature temperature so that enzyme is less active and Alpha-Amylase is doing most of the ‘work’. The net result is a wort with lots of dextrin. My take away is that if you mash at a lower temperature (e.g., around 147-150°F), extending the mash time will result in a more fermentable wort. If you mash at a higher temperature (e.g., 160°F) the Beta-Amylase can still do a little bit of ‘work’ but at a greatly slower rate vs. the lower temperature mash. If you conduct an extended mash at 160°F you will not get as much difference in wort fermentability. Cheers!
Any thoughts on whether this could impact head retention. One mechanism is by extended duration of the activity if proteases, I'm not sure if they would all be denatured. This was one of the reasons I was thinking about starting higher.
Peter, I would think that the proteolytic enzymes would be denatured at your infusion temperature; below is what Mr. Wizards states on this topic: “Some enzymes found in malt are extremely heat sensitive and never have a chance of surviving mashing if they make it out of kilning. These include lipoxygenase, phytase, beta-glucanse and a wide range of proteolytic enzymes. Most mashes begin no cooler than 140 ºF (60 ºF) and the listed enzymes have no activity in the mash because they are almost immediately denatured during mash-in.” I am unsure whether this ‘translates’ to all of the proteolytic enzymes are denatured but that would be my expectation. Hopefully somebody who knows for sure will chime in. Cheers! Jack P.S. The above quote is from: http://byo.com/hops/item/2051-what-...ymes-have-they-been-denatured-at-the-mash-out
Mash at 140F for three hours or more to make a lite beer. If you want more head retention, then do a rest at 158-160F for a half hour to 45 minutes.
