Bagel Bob Speaks: Good is Bad, Better is Worse!!!
Bagel warning: My bagels have been coming out with a progressively lower rise, and have consequently become very tough and dense. Pondering this, I realized that initially I had specified no rise time be allowed after forming the rings before they went into the refrigerator. BUT over time, I have gotten much faster at rolling the bagels — I can roll a dozen in about ten minutes. Following on this thought, I tried leaving them out in the covered jellyroll tray for 20 minutes after rolling, and the results were once again what they used to be. Moral: you can be too good for your own good. A short rise time turns out to be helpful. I now recommend that timing of the rise start when you first add liquid to the dry ingredients, and after 45 minutes to an hour, put the rings in the refrigerator. I doubt that anyone has yet been fast enough at rolling to run up against this problem, but I am continually looking out for the well-being of Stacy's people.
Secondly, I bought some of the Bob's Red Mill Malted Barley Flour from the grocery store at Eldorado to try it out, and in my first batch I used the same (2 tsp) amount that I had for with King Arthur diastatic malt powder. The resulting bagels were horribly gummy inside, a sign of too much diastatic malt. A later batch with 1-1/4 tsp of Bob's came out well. On reading the labels, it turns out that Red Mill is pure malted barley flour, and King Arthur's diastatic malt powder has wheat flour and dextrose in it as well, so it would exhibit less enzymatic activity for a given amount. I contacted King Arthur to find out what the proportions are in their product so I could calculate equivalencies, and received the following reply: "I'm sorry, this is proprietary info that the vendor will not share." So we are on our own here, but I suspect that 1 to 1-1/4 tsp of Bob's Red Mill Malted Barley Flour will be about right. I will keep you all informed of developments.
— Bagel Bob
