Delay Mashing Crystal Malts

I’ve had some similar post recently but trying to get more clarity.

It appears that my water is very sensitive to the acidity of crystal malts. I’d like to keep my mash pH up a little more and am considering putting the crystal malts (crystal and Carafara II) in later into the mash. This would keep the majority of the mash time with a slightly higher pH (5.4ish) vs. 5.05-5.1ish if I add the crystal for the entire mash.

Do anyone else use a technigue of delaying your crystal mash? If so, any issues with missing your OG, color, taste, etc?

My standard procedure is to add crystal and roasted malts at the end of the mash, when it is time to sparge. Doing so had no adverse affect on the target color or OG at all.

I don’t recall which commercial brewer it was that suggested the idea to me but when I tried it, it did seem to make for a smoother taste. In any case, that’s how I’ve done it for all of my brews for quite a few years now.
Definitely give it a try!

Now that I trust the Bru’nwater spreadsheet to accurately predict mash pH, I’ve been using the roasted and dark crystal malts to control pH rather than brewing salts and so far, it’s working really well. For instance, I’m doing a 17SRM IPA this weekend and using just 0.25 lbs of 150L crystal to drop the base malt pH to 5.3, then adding the rest for a 20-minute rest at the end of the mash.

Ah, so you are adding a portion of the grains to get the pH where you want to be, but then just adding the balance at the end to start to extract color, sugars and flavor?

Thanks for you input too “Professor”.

Man, I’ve been reading about this more and more lately. It’s fascinating. Makes so much sense, I’m going to start playing with this idea too.

Very interesting indeed! I have a couple clarifying questions. You only add your base malt + enough caramel/crystal/roasted to bring your mash PH in line? What is the consensus time to add color malts into the mash, 20 minutes? Also, do you start your mash (with only base malt) with enough water for the total grist, or do you add more water with the color malt addition?

I was going to add mine at 20 mins with what Shadetree suggested and i was going to Mash with the water amounts as if I had 100% of my grain bill in there. My thought behind that is, if you don’t you’ll have to adjust water temperature and volume later as you add more grains. Seems like a lot to mess with. I may even mash slightly higher (1-2 degrees) so that when I put the balance of my crystal malt in at the end and stir that I’ll have a few degree of temp loss and end up where i want to be for the last 20 minutes.

  1. Yes. 2. Not a consensus (when is there ever a consensus in brewing?), but IME 20 minutes is plenty to extract the sugar and allow the enzymes time to work. 3. I mash with all the water, and mash thin too (1.6+ qt/lb), then add the rest of the dark grain at the same time as the temp boost (after mashing for ~60 minutes, I add boiling water to boost the temp to ~165F for a 20-min rest before draining).

The thing I always thought was better about AG was that you got better extraction from your specialty grains than steeping for an extract batch. Now you guys are basically steeping. I guess crystal is pretty much converted already, but any lightly kilned malt like biscuit could surely stand to be mashed for the full length of time.

I totally agree Tom! I only plan to do this with the highly kilned malts that significantly move by pH lower. And I may not do it all the time. If my full grain bill gets my pH where I want it. I’ll just put it all in. It just so happens to be in the recipe I’m doing that my pH gets too low for my liking and instead of adding stuff to increase the pH, I can adjust how I mash the kilned grains.

Biscuit isn’t dark crystal or roasted malt, so it should be mashed as usual. When I use this method to make Stout, I do a regular 60-min mash, then add the dark malts for an additional 30 minutes (the mash now has enough buffering power to keep the pH in range with no addition of chalk or lime). The efficiency remains the same as when everything is mashed together.

How does the mash have more buffering power after sitting for 60min?

Also, how are crystal malts high in acidity?

[quote=“tom sawyer”]How does the mash have more buffering power after sitting for 60min?
Also, how are crystal malts high in acidity?[/quote]
Anecdotal only, but when I mash my Stout with no dark crystal and no roasted malt, I can hit 5.2 with no salt additions, go an hour, then add the dark malts and it stays at 5.2 - my assumption is that the large volume of wort is enough to buffer the acidity. Mashing the entire grist from the beginning requires large amounts of chalk or lime to keep the pH down.

Go much darker than 20L, crystal or roast, and you’ll be adding acidity to the mash.