Mash Tun Size for 5 Gallon Batches?

[ultravista]

I have both the 5 and 10 gallon round Rubbermaid (Home Depot branded) water coolers.

My first all grain batch is this weekend; the grist bill is about 13 pounds.

For a batch this size, should I use the 5 or 10 gallon mash tun?

I am concerned that the size of 10 gallon cooler may have too much headspace that would negatively impact the mass temperature.

Am I on the right track? For 5 gallon batches, which would you use?

 

[lumpher]

you'd be able to get the 13 in the 5 at about 1.2 qts /lb and be ok, i'd think. just be careful stirring. during the colder months, i actually use a 58 qt (14.5 gallon) rectangular igloo cooler for everything, 5-12 gallons.

 

[dammit711]

I use a 10 gallon round cooler, and I'm only doing 3.5 gallon batches. I have had no problems with with my mash temperatures. I'm only losing around 1 degrees in a 1 hour long mash. If you are going to make a big beer you may have a problem with the 5 gallon cooler. I went with the 10 gallon in case I make bigger batches in the future.

 

[wolverinebrewer]

I have both the 5 and 10 gallon round Rubbermaid (Home Depot branded) water coolers.

My first all grain batch is this weekend; the grist bill is about 13 pounds.

For a batch this size, should I use the 5 or 10 gallon mash tun?

I am concerned that the size of 10 gallon cooler may have too much headspace that would negatively impact the mass temperature.

Am I on the right track? For 5 gallon batches, which would you use?

The 10 gal. will be fine. Figuring 1.25 qts water/lb. of grain will put you at 4+ gal. Adding in the grain will take even more space utilizing more than half of the volume. If its a quality cooler you should be able to hold temps. If you are worried, keep a blanket over it. Also, pre-heat.
FWIW, I have mashed 10 lbs. in a 62 qt with no issue and that was outside in 25* temps.

 

[trub quaffer]

I use a 10 gallon Home Depot beverage cooler for all of my 5 gallon batches.
Assuming a 1.25 qt/lb mash thickness, you're going to need over 4 gallons of water. I don't know that you would have room in the 5 gallon cooler. I've found that I lose about 2* every time I open the lid when mashing a 5 gallon batch. So if I want to mash at 153* I just make sure the temp is 155* before I close the lid and hit it dead on. Just remember if you open the lid for any reason after that, you're going to lose another 2*.

 

[pfooti]

http://www.rackers.org/calcs.shtml

Good site for mash calcs, including one that predicts the volume you'll need to mash your grist.

FWIW, I use a 10 gallon victory cooler for my 5 gallon brews. Works fine; the only thing you need to worry about is the "fudge factor" in heat absorption into the cooler. For me, that's about 2.8 degrees F.

I lose a degree or two, tops, over the course of the mash. Not a problem. If you've got two coolers already converted, there's probably nothing wrong with going with the smaller cooler (although that'll have a bigger surface area to volume ratio, which could easily offset the headspace heat loss, actually now that I say that, I think it might be true- I'd bet the bigger cooler loses less temp over time, but has a bigger initial drop). But if you're only converting one, then definitely go with the 10gal cooler, as you'll eventually want to brew a big ol' 1.080+ beer, and you'll be happy for the space. I did a wee heavy that ended up with like 30 quarts of strike water or some such.

 

[jafo28]

pfooti, you beat me to it with the link!

 

[ruffdeezy]

After about 5 batches in my 5 gallon rubbermaid, I retired it. Just too small. The 10 works just fine and holds temp perfectly even for <10lb grain bills.

 

[BendBrewer541]

I have to say that my 10gl HD Rubbermaid cooler rocks. I only do 5gl batches and the 10 gl size is very handy, even for higher gravity brews. I only batch sparge. I've never had an issue with heat loss what so ever. I brew in my garage which is usually above 60 degrees during the winter. I'm amazed at how well they hold the heat, providing you don't open the lid! Personally I see no need for the 5gl size; save the money for some extra brewing equipment or ingredients.

 

[shelly_belly]

Well here's what a 12.75 pound grainbill mashed in at 1.25 quarts/pound looks like. Actually it didn't all fit - I had to scoop 2 quarts out (put it in a 1/2 gallon insulated water jug) to get all of the grain in. After 60 mins I was able to put the 2 qts back in the 5 gal cooler before the sparge.

 

[rico567]

I use the 10 gal Rubbermaid cylindrical cooler. It's large enough to mash any but the most theoretically big beers. My last batch for Fall 2010 was the Founder's Breakfast Stout clone from the recipes section. It's about a 22 lb grain bill, and the MLT was filled to within about 1.5 inches from the top. Nearly too hard for me to lift.....but the results were completely successful, the beer is great.

 

[jfowler1]

Well here's what a 12.75 pound grainbill mashed in at 1.25 quarts/pound looks like. Actually it didn't all fit - I had to scoop 2 quarts out (put it in a 1/2 gallon insulated water jug) to get all of the grain in. After 60 mins I was able to put the 2 qts back in the 5 gal cooler before the sparge.

That's a great post; pictures are worth a thousand words.

I also mash in a 5 G cooler at 1.25 qts/lb and I can barely close the lid with grainbills of 12.5 lbs. If you knew your efficiency, you can get a little better advice as to which size you are better off with. I plan my recipes at 80% efficiency, so it allows me to top out with all grain recipes around 1.065 OG. For reference, I believe the Janet's Brown recipe is 1.066 OG. I like the 5 G for my needs, but if I was starting from scratch, I would think about going with the 10G. I will add something else, If you only plan to do a "big" beer once in a blue moon, you can still max out your 5G cooler and make up the difference with DME. When you are talking barleywine style beers, the small % of DME will be far from noticebale. It seems a little silly to buy equipment based on the exception instead of the rule. Also, I have an Imperial IPA recipe planned that calls for a pound of sugar to help dry it out. In this case, it is only a 11.5 lb grain bill, but has an OG around 1.070. A strong Belgian-style beer would be a similar scenario.

On the other hand, while the 10G cooler is overkill for most 5G batches, it allows you to easily upgrade to 10 G brewdays, or as noted, make 5G of a beer that requires 22 lbs of grain.

It is a nice problem to have.

Joe

 

[erikhild59]

I can squeeze 13#s in my 5 gal cyl but i have to sacrifice my ratio a bit .. my advice is use the ten if youve got it.Maybe preheating will help if youre worried about bleeding heat.You could always add hot water towards the end too.

 

[Brewfat]

Make a disc out of foam insulation wrapped in foil and push to top of the mash.

I do this when using a 10g with small grain bills and never lose a degree. I have a 5g but never use it anymore.

 

[ThePearsonFam]

I wouldn't worry about the head space much at all. I'd be more concerned about having enough space.

You can always thin your mash out a bit too (anything between 1.0 to 2.0 is good), I use 1.5 and have great luck. The head space is lessened if you thin it out a bit too.

Another consideration is pre-heating the MT with hot water prior to introducing the grains and strike water. Just put boiling water into the MT and cover it with the lid/blanket for about 20-30 minutes.

Just a couple thoughts...

 

[Newgene]

Use the 10. The heat transfer difference due to head space would be minimal. I always wrap my coolers in a blanket after I close them anyway. I may lose one degree over an hour. As long as you cover the areas of least insulation (i.e. the lid), you will drastically increase your heat retention.

BTW, my brew today was 6.8 lbs of grain for a 2 gallon batch. I used the 5 gallon, and it was over halfway at 1.25 qt/lb.

 

[Soulshine2]

Well here's what a 12.75 pound grainbill mashed in at 1.25 quarts/pound looks like. Actually it didn't all fit - I had to scoop 2 quarts out (put it in a 1/2 gallon insulated water jug) to get all of the grain in. After 60 mins I was able to put the 2 qts back in the 5 gal cooler before the sparge.

that photo seals the deal for my curiosity . 10 gallon it is.

 

[olie]

http://www.rackers.org/calcs.shtml

Good site for mash calcs, including one that predicts the volume you'll need to mash your grist.

Great link, thanks!

FWIW, I use a 10 gallon victory cooler for my 5 gallon brews. Works fine; the only thing you need to worry about is the "fudge factor" in heat absorption into the cooler. For me, that's about 2.8 degrees F.

I lose a degree or two, tops, over the course of the mash.

Do y'all not "pre-heat" your coolers? Like just put a couple of quarts of boiling water in and slosh it around to get the sides "warmed up"?

Good idea? Waste of time?

Thanks!

(Yeah, yeah -- ancient thread. Such is n00b-life!)

 

[wilserbrewer]

Great link, thanks!



Do y'all not "pre-heat" your coolers? Like just put a couple of quarts of boiling water in and slosh it around to get the sides "warmed up"?

Good idea? Waste of time?

Thanks!

(Yeah, yeah -- ancient thread. Such is n00b-life!)

Easier imo to overheat your strike water by about 10 degrees and add it to your cooler to preheat. After 5-10 minutes allow to cool to strike temp by stirring or adding a few ice cubes to temper to exact strike temp.

This way the cooler and strike water are at an accurate strike temp.

The couple quarts idea is wasted effort imo and doesn’t really preheat that well or that accurately.