Cooler mash tun sizing

How many lbs of grain can you fit into your cooler mash tun, What size is it? Going to finish making my herms system (thanks for the help tnlandsailor) over the next week and I still need to pick out a cooler. I will be doing 5 gallon batchs, but I may like to try a all grain barley wine. So I will need room for that.

thanks

I have a 5 gallon cylindrical cooler. It's fine for a regular batch of five gallons. If you go for anything of high gravity, it might not all fit. I haven't maxed mine out yet but I don't think I would try much more than 12-13 lbs. of grain in it. Going by memory I believe Orrelse has posted recently that he can only do an OG of up to 1.068 or something close to that in his. A barleywine that needs 20 lbs of grain for a 5 gal. batch would need a 10 gal. cooler. By the way, I'm planning a barleywine soon, but I'm going to make it a 3 gal batch so I can fit it all in.

I would stick with the retangular coolers, espeically for a recirculating system. A standard 48 - 50 quart cooler is perfect for the 5 gallon batch, even a 5 gallon batch of a high gravity beer. If you plan on graduating to 10 gallon batches later on, you can still use the 48 - 50 quart cooler, it just gets REALLY full and you are definitely limited to beers around 1.055 or so.

Just a couple of months ago, I was in the market for new mash tun. I had been using a 48 qt Igloo but I wanted to be able to do 10 gallons without filling the thing right to the brim. I lucked out and found a 60 qt Igloo at Sears. I had never seen standard coolers in this size before and after I bought it, I tried to find it on the Igloo website and couldn't find it listed there. It could have been a special for Sears only. It's a little late in the year to find a good selection, but keep your eyes open, you never know what you might run across.

Prosit!

tnlandsailor, do you have any problems with a shallow grain bed and lack of filtration when doing five gallon batches in a 48qt cooler? I would imagine your grain bed is three to four inches in depth only. I have read that six inches should be a minimum with up to a foot of depth being even better.

I've got a 5 gallon round Coleman 'Extreme' (or whatever the silver ones are called) that I do 5g batches in. I did one batch with 14lbs of grain and it was capable when filled to the brim and a slightly thick mash. In reality, 13lbs is about the most you want which, according to Promash, results in ~4.85g total volume if you go 1.15qts/lb.

I recently picked up a 40qt (I believe) 'Extreme' which I will be outfitting and using for grain bills > 13lbs. For 13lbs or less I definitely plan to stick with my round cooler as it seems more efficient to me.

One of the things that concerns me the most is the fact that I was geting about 55% effenceny on my system before. The herms will help that some, and I plan on getting all the stuff to watch and change ph shortly. But it is hard to get all the grain in with such bad effency in my system before.

DyerNeedOfBeer said:

tnlandsailor, do you have any problems with a shallow grain bed and lack of filtration when doing five gallon batches in a 48qt cooler? I would imagine your grain bed is three to four inches in depth only. I have read that six inches should be a minimum with up to a foot of depth being even better.

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The only thing that matters is to get the runoff to be as clear as you can. In a recirculating system, you avoid some things that a standard mash has to deal with, mainly, the time and agitation caused by the vorlauff (manual recirculation). A thin grain bed can be disturbed a lot easier than a thick one, which will give you less clarity, that much is true. But if you never have to disturb the bed, then it's a non issue. A recirculating system (if you design it right) recirculates constantly which gives you unbelievable runoff clarity. Also, since the return manifold is located just below the wort surface, there is no disturbance of the grain. These two things allow a much shallower grain bed with unmatched runoff clarity. Yes, my grain bed for a 5 gallon batch is in the 3 - 4 inch range, but it has never been an issue. The runoff has always been crystal clear because of the hour long recirculation and the return manifold located just below the wort surface.

jjsscram said:

One of the things that concerns me the most is the fact that I was geting about 55% effenceny on my system before. The herms will help that some, and I plan on getting all the stuff to watch and change ph shortly. But it is hard to get all the grain in with such bad effency in my system before.

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I think the HERMS design will help your efficiency, just as long as you measure it in the exact same way as you do now. I don't know how you sparge now, but the HERMS design really begs for a fly/continuous sparge method, which should also help efficiency. I'm not sure, but I think batch sparging requires some stirring somewhere along the way which totally undoes all of the clarity acheived by the hour long recirculation, therefore, I don't recommend it.

In short, don't worry about the shallow grain bed, you'll be fine.

jjsscram said:

One of the things that concerns me the most is the fact that I was geting about 55% effenceny on my system before. The herms will help that some, and I plan on getting all the stuff to watch and change ph shortly. But it is hard to get all the grain in with such bad effency in my system before.

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So many things affect efficiency that it's almost academic to discuss it over the internet, BUT I measured my ph for the first time my last batch and found it to be > 7 (I use tap). I added some lactic acid which got it down to 5.0 (was shooting for 5.2) and my efficiency went from ~60% to 69% for that batch...not bad! Of course, without more runs it's hard to say if it was an anomaly unrelated to my ph correction, or due to a new recipe, etc. I was, however, encouraged.

I'm in the UK so forgive the use of kilos and litres but it makes life SOO much easier in situations like this...

As a general rule, 1kg of grain takes up 1 litre of space. Its actually a fraction more when mashing due to absorbtion but its very slight it doesn't really make a fat lot of difference.

So for every kilo of grain you use, you need 3 litres of volume in the tun if you're going for a thick mash (2L/kg liquor/grain ratio). A more regular mash thickness of 2.5L/kg and you'd need 3.75L per kilo. A thin mash of 3L/kg is obviously 4L of tun space per kilo of grain.

A 10 US Gallon tun (38 litres) will give you room for 12kg of grain at 2L/kg which at about 75% efficiency should yield 5USG of 1.150 wort.

For your 5 gallon batches, use 2.5L/kg and 4kilos of grain and you would have the option of batch sparging.