Ageing/storing malt

[SomervillesBrew]

I have just read that pale malts are beleived to improve if stored for 1-3 months before being used in brewing. What happens in the malt during those 1-3 months that improves it? How does it improve?

Also I thought the shelf life on malt (stored cool and dry) was about one-year, or on pre-milled malt it was one month, is this true? I realize that storage conditions will affect the shelf life.

[Ted Briggs]

I think you might be confusing the storage of malt BEFORE malting. This is done to simulate the natural dormancy of malt before growth. Malsters typically use techniques to shorten this time.
Ive always thought that uncrushed is about 3 months and crushed one, assuming good storage conditions.

[gitchegumee]

Although my location dictates longer malt storage times, I cannot tell any difference in malt stored 9 months after manufacture vs "fresh". Of course this is with temperature and humidity control.

[SomervillesBrew]

What I read was definately refering to malt, not grain before malting. I read it on page 218 from the Malts and Malting book by Dennis E. Briggs.

"However, while pale malts are beleived to improve if stored for 1-3 months before being used for brewing, many special malts lose their characteristic aromas and should be used soon after being made."

[BelgianBrews]

Enzymatic activity, and therefore extract recovery improves when malt has been stored for 6 weeks or longer before mashing. I have no idea how flavor compares. If you are trying to store milled malt, you need to watch your temperature and humidity. Also you will have a loss in flavor and aroma when storing milled malt for long periods of time, even if you don't have mold growing!

[Woolsocks]

At Siebel, they said you needed to store finished malt for 21 days before brewing, but the reasons weren't clearly understood. Apparently not doing it results in haze and fermentability issues. In any case, I don't think the maltsters release malt that hasn't aged long enough.

[South County]

At Siebel, they said you needed to store finished malt for 21 days before brewing, but the reasons weren't clearly understood. Apparently not doing it results in haze and fermentability issues. In any case, I don't think the maltsters release malt that hasn't aged long enough.

Exactly, I think some context is whats needed here. "Aging" is relative to when the malt was first finished. Also with detailed brewing text you have to take some things less literal than they read. If I had to guess the storage to lessen haze is so that the malt can stabilize (mainly the starch modification). Under-modified malts particularly 6-row varieties for lager brewing almost always need a protein rest in the mash schedule to reduce haze.

[Beer Sleuth]

I did research years ago using a Viscoamylograph and showed that changes in the viscosity of malt paste relative to its own amylolytic activity occurred around 20 days after kilning. I surmised that this was due to the fact that malt, having been hydrated to 45% during steeping and germination then dried rapidly to 3-6% moisture in a day or less resulted in a grains that, even though they average 3-6% moisture in lab analysis are actually grains of 0-1% moisture on the outside surface and 6-8% moisture in the endosperm. When the grain is ground the super-dry outer layer "powder coats" the little doughballs formed by the relatively wetter endosperm, forming little balls of water-, and therefore, enzymatic hydrolyis-resistant doughballs. I reckon that it takes 3 weeks for this moisture disparity to equilibrate across the entire malt grain, making it mill and extract properly. Brewers should not assume that maltsters have aged their malt for a minimum of 3 weeks and should ask for kiln dates to be printed on their certificated malt analyis or bags. Those of you that brew in higher humidity environments should also be wary of malts that are more than one year old, because the dry malts will actually re-absorb moisture from the air over time similarly affecting milling and extractability.

[jerrymcmahan]

According to Greg Noonan, fresh malt is stored for 30 days or so after drying/roasting to allow undesirable volatile aromatics to dissipate. Makes sense but I've not seen this elsewhere.