Pondering mash out and sparge temps...

[ericwatkins_utk]

Hey guys - Its been a while.

So I was pondering over mash out today - I've always used a 10 gal Igloo cooler for my MT and I love it - except for the inherent challenge of raising temps. I usually use a grist ratio of about 1.5 and like where I'm at. Since raising the mash temp to mash out ranges requires an infusion of boiling water in the case of a cooler, I usually just skip the mash out.

With that being said, I still use 170F water during my fly sparge and sparge very slowly for about an hour or longer till I hit 1.008. I've always done this because that is what I've read in Palmer's book and on here over the years. However - Is this the right approach for someone who skips a mash out??

My thinking is that if I am brewing a dry recipe - say in the 148-152F temp range - then I fly sparge for an hour at 170F then the grain bed will never really reach 168ish for a mash out, but it will slowly rise to somewhere in the upper 150's or low 160's. It seems that somewhere during the sparge that I would begin disolving more complex sugars that I am not interested in since the intent was a low mash temperature.

So - If someone skips the mash out on a dry recipe, should one just skip the 170F sparge and instead sparge with water at the same temp as the mash? That way over the hour course of the sparge, the grain bed temp would remain consistent with the mash and you would not run the risk of more complex sugars in the wort??

Am I flawed in this line of thinking outside of the box?

 

[Matt3989]

My thinking is that if I am brewing a dry recipe - say in the 148-152F temp range - then I fly sparge for an hour at 170F then the grain bed will never really reach 168ish for a mash out, but it will slowly rise to somewhere in the upper 150's or low 160's. It seems that somewhere during the sparge that I would begin disolving more complex sugars that I am not interested in since the intent was a low mash temperature.

Thinking of this as "dissolving" the sugars is not really accurate. It's really enzymatic activity. Malt had starches, not (in most cases) simple sugars like you're thinking of. Instead you are soaking the malt to extract the starches, this is why an iodine test at the start of the mash reacts the way it does.

Now, you're holding a certain temp to allow the enzymes to work in their most efficient ranges, alpha amylase works in best in the higher range, beta amylase in the lower range. Alpha will leave you with longer chains of sugars which will be unfermentable, beta will leave you with simpler more fermentable sugars.



The purpose of the mashout is to stop that enzymatic activity at the desired fermentability. So you are right in that if you are shooting for a dry beer, a mashout is not necessary, the enzymes can keep working and your wort will only become more fermentable. However, if you want a fuller bodied beer, then a mash out will stop the amylase enzymes from working and leave your wort at your desired fermentability.

The other purpose of hot water is to aid in sugar solubility so that you can rinse more sugars out of your grain bed. There are lots of opinions on that here. Personally, for the price of grain, and the hassle of heating water up, I don't think it's necessary to squeeze every drop of efficiency out of your mash. Hot water also runs the risk of extracting tannins (if your ph is too high).

 

[ericwatkins_utk]

The other purpose of hot water is to aid in sugar solubility so that you can rinse more sugars out of your grain bed. There are lots of opinions on that here. Personally, for the price of grain, and the hassle of heating water up, I don't think it's necessary to squeeze every drop of efficiency out of your mash. Hot water also runs the risk of extracting tannins (if your ph is too high).

I agree "dissolving" wasn't quite the right choice of words as far as conversion goes. I was thinking of dissolving more from the hot water and solubility aspect above.

I completely agree with the hastle of heating water and trying to get every last efficiency point.

I used to try to raise the temp to mash out with sparging with a near boiling water infusion, but I always feared the near boiling water would begin to extract tannins, so I quit fooling with the mash out in a cooler. I'm with you. Grain is cheap in relation to all of the other ingredients.

Now that I've talked thru this a bit, I almost guarantee this is what is responsible for the many times I've missed my FG by a couple points high.

I tend to brew on the dry-er side and have just had an uneasy feeling about the whole 170F sparge w/o a mash out. I think I will try sparging a batch at my mash temp and see what happens. I can probably benefit from the longer time in the enzymatic range any way.

Loosing that solubility benefit of the hot water is really my only concern
Sounds like a good experiment is in hand.

 

[skunk27]

Now that I've talked thru this a bit, I almost guarantee this is what is responsible for the many times I've missed my FG by a couple points high.

I tend to brew on the dry-er side and have just had an uneasy feeling about the whole 170F sparge w/o a mash out. I think I will try sparging a batch at my mash temp and see what happens. I can probably benefit from the longer time in the enzymatic range any way.

Loosing that solubility benefit of the hot water is really my only concern
Sounds like a good experiment is in hand.

Hey Eric, I'm wondering how this turned out for you and if the lower sparge temperature gave you more fermentable sugars as you were expecting.

I've been having attenuation issues on-and-off for a while now too and am starting to run out of ideas. I'm as sure as I can be that the usual suspects (mash temp, pH, pitch rate, wort aeration, fermentation temp etc) are all fine and am really struggling to pinpoint the problem.

My process sounds very similar to yours and I'd suspected the same problem as you'd outlined in your first post: the unintended activity of alpha amylase enzymes due to sparge water being higher than mash temp while not being hot enough to denature the enzymes. I wouldn't have thought that the fermentable sugars that had already been converted could somehow transform into unfermentable sugars due to a higher temperature from sparging, but my assumption could definitely be faulty. Or is it possible for there to be starches left at the end of the mash that would respond more to alpha rather than beta amylase? (sorry, I'm rambling a bit now, but like I said I'm getting a little desperate! )

I'll definitely be running the sparge water at mash temp for at least the next couple of brews to see how that turns out anyway, but if anyone has any theories on this (scientific or anecdotal) then I'd be interested to hear.

 

[WavePuckRiker]

Ironic how I logged in to find the same info and/or pose a similar question!

I have about 15 batches under my belt thus far. They have all come out very well and the last 5-6 have been really good....at least that is the feedback I have been getting. Lately, it's been mostly IPA's and pale ales.

I have been mashing in at 163-165 (pending recipe), to step at 152.

Mashing out at 208 to step at 168.

Fly sparging at 168.

I use a 10 Gal Rubbermaid cooler with Krome false bottom to mash.

My beers have tasted great, although I would like a lighter body. Would mashing at a couple of degrees lower achieve this? Also, is there a direct relationship between body and color? I would say that my color seems to be a bit darker than projected, and I am regularly 2-3 points high on starting gravity.

Thanks in advance for any suggestions!