I have been noticing that when i use a large portion of specialty malts i tend to have decreased efficiency. All my parameters are controlled. All grain: PH, 1.75qts/lb, crush is good. I batch sparge and mash for 75min and have be up to 10% lower on my efficiency. I have yet gone through a “brewhouse efficiency” test to try and figure out at what stage i have having issues ( conversion or lauter) but i am assuming its conversion. So ? is do any of your ladies have issues when using higher levels of specialty malts with conversion? Also i am assuming that higher roast malts have less enzymatic power? my most recent was an southern english brown. 64% MO, 12.9% C80, 8% C120, 6.6% special roast, 4.8%pale chocolate, 3% carafa ll. mashed at 148F 75 min.
Crystal malts and roast malts have 0 DP, as the enzymes are denatured from the high temperatures.
MO does not have excessive amounts of DP. You might try mashing thicker, 1.25 qt/lb, or adding in some NA 2row to increase enzymes.
It’s not a low enzyme issue. However there might be a mash pH issue at play here. How soft is your water? If using distilled or RO water, with about 35% specialty malts in there, your mash pH might fall as low as 4.8 to 5.0, which is on the very low end of scale. Your finished beer might even taste quite tart and acrid at that low of mash pH. Are you adding any baking soda to bring mash pH up?? You should, unless your water is very hard.
Are you accounting for the differences in potential extract? If the base malt is at 82% and the specialty malts average 72%, the overall PE would be about 5% lower than for the base malt alone.
mash PH is 5.45 room temp. my house water is basically only good for stouts:) my bicarb is 308ppm. Good point on the potential extract. i use software and there PE could be different than what is actual. Also i didnt mention before but my mash temp did drift down to 145F over 75min maybe in this case this could be a reason. Maybe i could try a step mash next time to insure optimal environment for beta and alpha. It’s just strange i never have problems unless i have a higher adjunct/ lovibond specifically beer.
I don’t think it’s a temperature thing falling from 148 F to just 145 F, unless your thermometer is wrong. Have you calibrated it lately, in boiling water, adjusted for your elevation? You’d have to look up the boiling point at your elevation. Also helps to compare to other thermometers if available. Personally I calibrate mine in both boiling and ice water so I know it’s pretty accurate, although it’s been a few years so I should probably do that again.
I am figuring that grain bill puts you at about 32 Lintner diastatic power. According to Breiss that’s a conversion step of naptime. There are other variables, but DP can be a biggy. Crisp MO is 50 maximum Lintner, others are even lower.
Minimum, according to their site. http://www.crispmalt.co/docs/Finest%20Maris%20Otter%20Ale%20Malt.pdf
Typically about 80 Lintner IME.
Funny how the fingers can type the opposite of what your thinking. Of course you are right.