Convert diastatic malt to non-diastatic?
Okay so I've been saddled here with like six pounds of diastatic malt powder. Works as advertised but way more than I'll ever use in a year. Also am in need of some of the non-diastatic malt for my bagels, thus:
Anybody know whether and how it would be possible to convert diastatic to non-diastatic malt?
I know the enzymes are destroyed when heated above 130°F. But would simply roasting or simmering the diastatic malt produce the same kind of non-diastatic malt sold as a sweetener? The stuff I bought on sale from King Arthur most definitely does not taste sweet at all, and smells almost of mold. But it is fresh and clean in appearance, bags were pristine and not at all close to expiration date, so am guessing it is just the active enzymes that are so olfactorily off-putting?
Any insights would be most appreciated.
The reason KA diastatic malt powder isn't sweet is the amylase enzyme requires water to activate it. Once active, in a wet mixture with flour it will begin to convert the flour's starch to sugars. In the beer-brewing process this is what the "mashing" step does. Cracked malted-barley is usually the source of amylase in beer-brewing. The barley derived amylase enzymes (there are two versions in barley) do their best work between approximately 140°F and 158°F. They are destroyed at temperatures above 168°F. Mashing is a slow process. Typical mash times are one hour to one and one-half hours.
The closest analogs to mashing in bread making are autolyse and bulk fermentation, but they are not identical. Adding yeast to the mix (wort) in beer making is the very last step.
Amylase added to flour may be from barley grain, but there are other sources also used. A common one is derived from a fungus. This may be the one you cited denaturing at 130°F. I've tried to find the active temperature range for fungal amylase, but haven't been successful.
I guess you could try an experiment: mashing flour. I wouldn't try it.
You can buy non-dastatic malt syrup on-line, at some health-food stores, or malt extract can be purchased at a home-brew shop. Don't use the adjective diastatic when asking for it. The word is not in most brewer's lexicon. Simply ask for a light malt extract syrup (un-hopped, if asked). It also comes in dry form, but I recommend the liquid extracts. I believe all brewing malt extracts are non-diastatic, but not to worry; once added to boiling water any remaining amylase enzymes will be destroyed.
As to the olfactory issue: I just sniffed the diastatic malt powder (KA) I've been using for about two years. I wouldn't call its odor inviting, but I don't find it offensive. Why did they have it on sale???
Happy baking,
David G
Thanks for the explanation, David. Yes I was wondering too why KA had the malt on sale at such a ridiculously low price. But if you check their weekly specials you will sometimes find equally inexplicably great deals. Again, I don't think the malt was "off"; perhaps its active enzymes are just similar to those of the fungus you mentioned, which might account for the distinctive aroma. Anyway, it works as advertised, my rye bagel dough rises quite well in the fridge now and takes on a reddish blush when boiled and baked.
None of my local HF stores carry malt in any form what so ever, and when asked the clerks would just look at me like I was from another planet (okay not so far off) nor are there any home-brew shops left around here (used to frequent them, long story.) Prices online for malt syrup or non-diastatic powder are just rediculuss, and as they are not essential for performance I'd just as soon use molasses and honey from the Fairway, have been happy with those results.
Still I have five more pounds of diastatic malt here than I can use this year, so if anybody here is looking for a bargain, send me a PM! ;D