[skyler]

My wife and I bought a house last summer, and I've been storing grain in the garage. Previously, when I lived in apartments, th grain was stored in whatever temperature it was in the apartment. This meant the grain was stored generally no colder than 58º F on a cold day when I was at work and no warmer than 85º F on a hot day because we had no air conditioning. It has dawned on me that my garage gets below freezing from time to time here in Portland - and that I am now storing my grain at a much colder temperature. Should I be concerned?

[fmader]

I really can't answer your actual question. But your strike temp for your mash water will vary based upon your grain temp. If your grain temp is 24 degrees, your strike temp will need to be higher than it would be for 70 degree grains in order to get your desired mash temperature.

[Steve Ruch]

My wife and I bought a house last summer, and I've been storing grain in the garage. Previously, when I lived in apartments, th grain was stored in whatever temperature it was in the apartment. This meant the grain was stored generally no colder than 58º F on a cold day when I was at work and no warmer than 85º F on a hot day because we had no air conditioning. It has dawned on me that my garage gets below freezing from time to time here in Portland - and that I am now storing my grain at a much colder temperature. Should I be concerned?

Keep your grain airtight and dry and you should be okay. Or use it up before it has a chance to go off.

[brewinhard]

I think you would be better off storing it in an airtight environment that is cooler than warmer.  Especially if your warmer tends to involve humidity as well as heat.  A humid environment will quickly make your grain go "slack" and not fit for brewing.  I experienced this a few years ago when I forgot about a 1/3 bag of dingemanns pilsner malt in my garage over the course of 2 mos during summer. After tasting it I knew right away it would not be worth using to produce a good brew.

[skyler]

A few more details:

I store in two ways:

1. For base malts, I use vittles vault pet food storage containers that can comfortably fit 49-50 lbs of grain. 25 kg bags need to be used down 5-10 lbs before they will fit into the storage containers.
2. Unopened whole sacks of base malt can sometimes sit (above ground) for as long as a couple months before I open them up. Meanwhile, smaller amounts of specialty grains will sometimes sit in ziploc bags inside the vittles vaults or just on top of them - usually the only specialty grain that I keep for longer than a few weeks is Carafa Special II.

Here in Portland the humidity is pretty high, but the grain will be kept dry in the storage containers. I know to adjust strike temperature and to keep the grain dry. My only concern is the storage temperature, because the temperature can go below freezing and I want to know if that means the grain will be damaged in some way. It sounds like it isn't an issue for Steve Ruch, who lives near me, so I suppose it's not a problem.

[brewinhard]

I would think that continual freezing and defrosting can't be great for the grain, so keeping it at more of a steady temp would be a better way to go if possible.

[BFBC]

I did not foresee providing advice on my first post, but I do have a lot of experience with storing grains and would like to help.  So, if you all will excuse my rudeness, I will introduce myself as a long-time brewer (1994) and move on to grain storage:

Grains can be stored for consumption for a very long time - many years - though I personally limit my brewing grains to two year or less.  They should be stored in an airtight container such as a 5g bucket with a gamma lid:

 http://www.amazon.com/gp/product/B005W31MLQ/ref=pd_lpo_sbs_dp_ss_3?pf_rd_p=1944687462&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B0089QJQTS&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=1X6P1EHP87JME6B5PFJN

If storing for a year or more without accessing the grains, throw in some O2 absorbers as well.  A 5g bucket will hold approx 25 to 28 lbs, BTW.

For long term storage, it is best to first freeze your grains - 10F or below for 48 hours to kill off any unwanted critters.  O2 absorbers will help kill critters as well.  You then want to store your grains in a cool, dry location  - 70F or below.  Avoid cycling temperatures if you can.  Constant temperatures are key here to avoid condensation inside the container. 

If you do crack a container at some point and find critters, immediately quarantine and destroy those grains to avoid infecting the rest of your supply.

Thanks for indulging me guys and hope this helps!

[Steve Ruch]

A few more details:

I store in two ways:

1. For base malts, I use vittles vault pet food storage containers that can comfortably fit 49-50 lbs of grain. 25 kg bags need to be used down 5-10 lbs before they will fit into the storage containers.
2. Unopened whole sacks of base malt can sometimes sit (above ground) for as long as a couple months before I open them up. Meanwhile, smaller amounts of specialty grains will sometimes sit in ziploc bags inside the vittles vaults or just on top of them - usually the only specialty grain that I keep for longer than a few weeks is Carafa Special II.

Here in Portland the humidity is pretty high, but the grain will be kept dry in the storage containers. I know to adjust strike temperature and to keep the grain dry. My only concern is the storage temperature, because the temperature can go below freezing and I want to know if that means the grain will be damaged in some way. It sounds like it isn't an issue for Steve Ruch, who lives near me, so I suppose it's not a problem.

I don't buy large amounts of grain so I usually don't have long time storage issues. I usually get some brewing supplies for xmas and my birthday (10-29). I get smaller amounts like 5 to 10 pounds of 2 or 3 different base grains and a pound or two of specialty grains. If I'm not going to use the grains fairly soon I vacuum seal them and stick them in a cabinet in my brew room. I've used grains in Sep/Oct of one year that I got late the previous year and have had no problems.
Vacuum sealing the grains for the 3 gallon batches that I normally brew is no big deal, but I imagine vacuum sealing a 55 pound bag of pilsner malt would be quite a chore.

[Philbrew]

It seems to me that moisture is a far bigger enemy of grain storage than temperature.  A couple of large (100 gm) silica gel packets on an aluminum foil "tray" on top of your grain in your airtight container might take care of that.
Any thoughts from the AHA forum on that idea?

[reverseapachemaster]

I'd expect any moisture in the grain would freeze and thaw with the temperature and break down the grain and make it softer. Maybe not enough to cause any flavor problems but enough to make it harder to get a decent crush. No idea how much moisture would be necessary or how much freeze/thaw cycles would be necessary to be a problem though. I imagine plenty of breweries in colder climates have external grain silos where this happens routinely without any problems.

[a10t2]

Thought experiment: if sub-freezing temperatures were a problem, most breweries wouldn't be able to use grain silos.

[factory]

Thought experiment: if sub-freezing temperatures were a problem, most breweries wouldn't be able to use grain silos.

I would assume that the large thermal mass presented by a grain silo storage system would help hold the grain at a fairly constant temperature.  Of course, I don't have any evidence to back that up.

[brewinhard]

Thought experiment: if sub-freezing temperatures were a problem, most breweries wouldn't be able to use grain silos.

I would assume that the large thermal mass presented by a grain silo storage system would help hold the grain at a fairly constant temperature.  Of course, I don't have any evidence to back that up.

Plus the sheer fact that a large brewery is going to use up those grains fairly quickly. As in they are not sitting around for months on end.

[Philbrew]

It seems to me that moisture is a far bigger enemy of grain storage than temperature.  A couple of large (100 gm) silica gel packets on an aluminum foil "tray" on top of your grain in your airtight container might take care of that.
Any thoughts from the AHA forum on that idea?

Sorry, I was not clear when I said that moisture is a far bigger enemy of grain storage than temperature.  I didn't mean freezing and thawing.  I meant spoilage and mold.