Home toasting/roasting malts and DP

As the subject title suggests I’m trying to produce some nice tasting malts, I was inspired by Randy Mosher in his book ‘Radical Brewing’.

If anyone has tried this before I’m interested in how base malts will be affected in terms of their diastatic power (DP) once I run them through the oven. I understand that malts kilned at lower temps eg, pale malts, pilsner malts will have higher DP. Other specialty malts tend to have lower or even no DP. I assume base malts, having already been kilned, will have their DP further reduced by me tampering with them.

The base malt I often use (Barret Burston Pale Malt) for brewing ales, is specced at 230 Lintner. Since I’m mashing with this malt as well as using it for my specialty base, I assume it will assist in converting the other lower DP malts. As a theoretical recipe:

  1. 4lb Pale Malt (Barrett Burston)
  2. 4lb Gold Malt (modified Barrett Burston Pale Malt) 25mins at 300F

Where;

  1. is 230 Lintner
  2. is assumed low or 0 Lintner

I did read that Beta-amylase can be reduced by as much as 60% by initial kilning but if anyone can pass on info, or experience, related to ABV outcomes using home-roasted malts, would love to hear about it.

My guess is that like brewing with chocolate malt etc that the batch limit would be lower. However, the malt isn’t caramelised to the extent that say crystal malt is, if at all.

Anyway I feel like i’m chasing my tail a bit here so am just going to stop typing. I think I’ve got the question out there.

Any help appreciated :slight_smile:

I don’t have numbers but my opinion is that you won’t affect the amylase quite as drastically as you are thinking. Plus you have enough activity in the malt to begin with that some loss wouldn’t lead to a failure to convert. You might mash a little longer if you think theres going to be a problem. If you have a refractometer its simple enough to follow conversion by tracking sugar content.

That’s good advice, I have a refractometer so i’ll monitor the mash closely and see how it goes. Not brewing until next weekend.

Cheers!

I believe 50 DP is the requirement for conversion. You’d be at 115, worst case, which is fine.

I soaked some grain in Liquid Smoke one time before roasting it to a med dark and used a strain bag in the wort. Turned out giving me a nice suttle smoke flavor on the back side of a Amber.