[samadams]

just curious if anyone knows how long crushed grain (in a bag) will last/be effective.  we have a bag about 2 months old from northern brewer stored in a cool area......thanks.

[kylekohlmorgen]

Most small brewpubs get their grain delivered pre-crushed... so keeping it for a few weeks shouldn't be a problem...

I don't know about 2 months... i would taste it. Check for taste AND consistency. If there are any band-aid flavors or if its chewy like oatmeal, its probably not good.

If you have ANY reservations about it after tasting, just throw it out... grain is cheap for us homebrewers.

[daubon]

I'm still using milled grain from a purchase I made close to a year ago.  It has been kept in the freezer.  I keep some in a cabinet in my kitchen (which is hot and humid).  All of it is in individual 3# sealed bags.  I've had no problems with it so far.  I have since purchased a grain mill since I do suspect that whole grain will keep better than crushed grain.

Pepe

[skyler]

I have use 2 month old pre crushed grain before without problems. It was stored mostly sealed (not airtight) at room temperature in my closet.

[lazyb34n]

After its been crushed you are exposing the enzymes, proteans and starches to oxygen and some moisture.  These will start to oxidize and denature.  I cant remember exactly (would have to look for the info) but it starts to affect efficiency after 72hours.   This isnt saying it goes bad after 72hrs but it starts to get noticeable after this time period.  This will greatly depend on how its stored, 

I had a buddy use crushed grain he left in his garage in a closed plastic bag for 2 or 3 weeks.  He did his normal mash time and temp but lost 10% efficiency, and the pale ale tasted a little off compared to his previous batch.

[dean]

I've got a batch of grain I crushed a couple of days ago and its been sitting in my tun waiting, might be interesting to see how it effects it.  Normally I don't do that but I've had to help a few people over the last few days and its been breaking up my schedule.  I do have grains that have not been crushed yet and I've kept in sealed buckets for over a year that seem to be fine so far.  The buckets are the type that have the silicone gasket in the lid so they seal well.

[pjj2ba]

As far as enzyme activity is concerned, 1 yr old crushed grain, properly stored, still has plenty of enzyme activity.  I think even two yr is OK - as far as conversion.  My wife uses this as a lab for her class and I designed it and prep the materials.  This last fall we had 2 yr old crushed to test but I never heard the results from my wife's teaching assistants.  I think it still converted.  This fall we'll have 3 yr old to test.

NOW, whether this tastes good is another question.  All we are testing for is enzyme activity. 

If the raw grain tastes good use it!

[tubercle]

After its been crushed you are exposing the enzymes, proteans and starches to oxygen and some moisture.  These will start to oxidize and denature.  I cant remember exactly (would have to look for the info) but it starts to affect efficiency after 72hours.   This isnt saying it goes bad after 72hrs but it starts to get noticeable after this time period.  This will greatly depend on how its stored, 

I had a buddy use crushed grain he left in his garage in a closed plastic bag for 2 or 3 weeks.  He did his normal mash time and temp but lost 10% efficiency, and the pale ale tasted a little off compared to his previous batch.

 Please find the info. As a novice trying to understand the science of brewing I would love to understand the function of a starches' exposure to oxygen and the effect it has on the efficiency of the mash. I'm especially interested in the denaturing part.

 Thanks,
Tubercle

[Kaiser]

I don’t think that the problem of crushed grain is denaturing of the enzymes.  The problems I have come across have to do with oxidation but I don’t know how much it takes to produce a noticeable difference in home brewed beer. This is very similar to the hot side aeration debate that flares up once in a while. Exposing just starch to air should not be a problem since that is what we do with flour all the time. There are also some fats and oils in the malt embryo which have the potential to get rancid when exposed to air. No idea if the small amount that is in there is enough to make a difference.

Just as a precaution I have moved milling my grain from the night before to the time when I heat the strike water on brew day. It fits right in that time, especially of I already weighed the grist.

If crushed malt is all you have or if your brew day gets pushed out then that’s what you have. Make a note of it in case you detect some trend in the flavor of your beers.

Kai

[denny]

I don’t think that the problem of crushed grain is denaturing of the enzymes.  The problems I have come across have to do with oxidation but I don’t know how much it takes to produce a noticeable difference in home brewed beer. This is very similar to the hot side aeration debate that flares up once in a while. Exposing just starch to air should not be a problem since that is what we do with flour all the time. There are also some fats and oils in the malt embryo which have the potential to get rancid when exposed to air. No idea if the small amount that is in there is enough to make a difference.

I agree that the issue is staling, not enzymatic activity.  I crush anywhere from 1-4 days in advance usually and keep the grains in a sealed paper bag.  I've never been able to detect any staling in that period of time.

[lbrewski]

I try to buy whole grain and mill it just prior to dough-in. But I have to plan and order on-line ahead of time because my LHBS has only pre-milled grain in bags ready to purchase. Hard to tell how long it's been there and I get a sour attitude if I ask for un-milled. Having said that, I've bought their grain days ahead or had to postpone a brew with no detrimental result as far as I can tell.