Finally brewed my first all grain batch! I have a question about mash temperature though.

[Beer Viking]

Hello everyone,

First of all I just want to thank everyone on the forum who helped me get to the point where I was able to do my first all grain batch! I went from beer kits to all grain because of you all!

My first all grain batch was pretty straight forward except I did not realize how quickly my strike water would drop in temperature by the time I added it to my mashtun. This being my first time doing all grain everything took a lot longer then when someone who knows what they are doing is making beer. I checked my mash temperature and it ended up being 134 degrees! My strike water was 165 but I'm wondering if that was too low? My hydrometer said I will get 5% ABV which is what I am shooting for. So what I am asking is one, did I ruin my batch and two if I mashed 20 degrees lower then I wanted would I end up with more fermentable sugars or non fermentable?

Thanks again everyone!

 

[lumpher]

165 should get you around 152, if the tun is warm. Was the grain or the mash tun cold? You might want to warm the mash tun up next time, if possible. If you mashed at 134 and didn't raise it, you can call this 1 "Sahara Dust Pale Ale".

 

[Willy]

Easiest way to to mash - 149° for an hour. Turn up the heat if you need to but try and hold 149°.

Depending on the style, sometimes I mash in at 135, hold 5-10 minutes, up to 143, 10 min., and 150 for 40 min. Using this method, I squeeze a little more wort into the fermentable range.

 

[Beer Viking]

Thanks! I did preheat my mashtun but it was a cold day and I did not get my strike water hot enough.

 

[Mike Bartodziej]

What are you mashing in? Is it a cooler, BIAB, or other? What size batch and how much grain and water? Did you take the temp right before adding your grain and immediately after stirring?

As previously mentioned, your mash temp should have settled in or near the 150's if your strike temp was 165. But if your mash vessel isn't insulated or there was something off about your ratio or a small batch size, that could have impacted how quickly you lost heat.

It's also worth considering your thermometer calibration. Was it reading accurately?

Either way, it sounds like you got sugar out of the mash, so your beer should turn out fine regardless.

 

[lumpher]

I did not get my strike water hot enough.

There's something else that's being missed. 165 is plenty hot enough if the tun is heated and the grain is room temp. Did you get the grain out of some kind of cold storage (outside in the cold, freezer, ...)?

 

[Brewer dad]

Beyond what’s already been asked, how are you getting the strike water into your mash tun? Are you running a line into it, pouring it, etc?

Assuming you had 10-12lbs or so of grain? Did you maybe spend a long time stirring?

Last thing I can think of, are you measuring temps with the same thermometers?

 

[worlddivides]

134 degrees at the beginning of the mash or the end of the mash? If it's at the beginning of the mash, that's technically just barely still within beta amylase's active range, but I imagine you'd need to keep it at that temperature for a pretty long period of time to get good conversion of the starches to sugars, and I also imagine the temp would fall below 130 pretty soon after that, especially if it had already fallen from 165 to 134. I think the lowest I've ever mashed at was 149 at the beginning of the mash and 142 at the end of the mash. It worked out perfectly fine (and I think it was the first time I didn't reheat, mainly because I wanted the wort to be super fermentable) and it was before I started insulating the mash to prevent the loss of heat as much as possible. I'd be interested to hear your OG and FG numbers for this beer.

 

[mac_1103]

that's technically just barely still within beta amylase's active range

Minor correction - it's just barely within beta amylase's optimal range. Mash enzymes are all active at much lower temperatures. They have to be to do the jobs they evolved to do (which, shockingly, is not to make beer and booze). They're just slower.

 

[worlddivides]

Minor correction - it's just barely within beta amylase's optimal range. Mash enzymes are all active at much lower temperatures. They have to be to do the jobs they evolved to do (which, shockingly, is not to make beer and booze). They're just slower.

True. The lower the temperature, the more time it takes, so you'd need to have a pretty long mash if you're going to be below 130. Granted, for all the folks that do overnight mashes, you could have it be at 134 or 124 or even lower and still have a lot of conversion, but those guys are mashing for something like 12-15 hours.

 

[doug293cz]

134 degrees at the beginning of the mash or the end of the mash? If it's at the beginning of the mash, that's technically just barely still within beta amylase's active range, but I imagine you'd need to keep it at that temperature for a pretty long period of time to get good conversion of the starches to sugars, and I also imagine the temp would fall below 130 pretty soon after that, especially if it had already fallen from 165 to 134. I think the lowest I've ever mashed at was 149 at the beginning of the mash and 142 at the end of the mash. It worked out perfectly fine (and I think it was the first time I didn't reheat, mainly because I wanted the wort to be super fermentable) and it was before I started insulating the mash to prevent the loss of heat as much as possible. I'd be interested to hear your OG and FG numbers for this beer.

Minor correction - it's just barely within beta amylase's optimal range. Mash enzymes are all active at much lower temperatures. They have to be to do the jobs they evolved to do (which, shockingly, is not to make beer and booze). They're just slower.

As @mac_1103 notes, the amylase enzymes in barley are active at temperatures much lower than typical mash temperatures. Barley will germinate at temps down to 39°F (4°C), and the enzymes must be active in order for the seedlings to grow (that is their biological purpose.)

The limiting factor is going to be the gelatinization rate of the starch, as starch cannot be hydrolyzed (broken down into simpler sugar) until it has first been gelatinized. Gelatinization is much slower at lower temperatures.

Brew on

 

[Beer Viking]

I mashed in a converted cooler and I spent a lot of time string in the grain on a cold day and my reading of 134 was after I was done striing. Also, I poured my mash water into the mashtun. My primary is going crazy right now and it smells like fermentation so I got some sugars out of it at least! My OG was 1.040 and my hydrometer said my ABV would be 5 %.

 

[Brewer dad]

I mashed in a converted cooler and I spent a lot of time string in the grain on a cold day and my reading of 134 was after I was done striing. Also, I poured my mash water into the mashtun. My primary is going crazy right now and it smells like fermentation so I got some sugars out of it at least! My OG was 1.040 and my hydrometer said my ABV would be 5 %.

Glad fermentation is going well!

Yeah I bet doing a lot of stirring and pouring your mash water while out in the cold contributed to the temp drop you experienced.

 

[hungupdown]

From OG of 1.040, you'll get an ABV of 5% if the FG reaches 1.000.
With beers, unfermentable sugars (or less fermentable ones, depanding on the yeast) might mean the FG is 1.010. Which (from 1.040 OG) would give an ABV of around 4%. BrewersFriend ABV calculator

However, if your mash temperature was on the low side, that should give a higher percentage of fermentable sugars. You'll only know, from the eventual FG reading,

If using a new hydrometer, it might be worth checking it's accuracy (and it's temperature correction factors, if provided) by taking a reading in water that's at around same temp as fermenter.

 

[Beer Viking]

Thanks for all the help guys! I racked to secondary today and it defiantly smells like a combination of alcohol and bananas! I was hoping it would end up tasting like bananas so I couldn't be happier! It's a nice blond color too! I'll post the FG when I know what it is too!

So a lower mash temp means more fermentable sugars and a higher one means less? Does this mean a low mash temp results in a dryer beer?

 

[worlddivides]

So a lower mash temp means more fermentable sugars and a higher one means less? Does this mean a low mash temp results in a dryer beer?

Yes. Generally when people want a dryer beer, they mash somewhere between 144F and 150F. When people want a beer with more mouthfeel (more residual sugars / unfermentable sugars, at least by most yeasts), they typically mash between 154F and 160F. You'll find that the vast majority of beers, though, are mashed in between that with the most common mash temperature being 152F.