I had read somewhere that most of an AG starch conversion happens in the first 20 minutes of the saccharification rest. That doesn’t seem to be the case for me today. I’m 115+ minutes into my saccharification rest at 153F and the gravity is still climbing. I did a mash rest for 15 mins @120F (protein), 15 mins @140F, 60 mins @153F and noticed my gravity was super low - 1.045 (wanting 1.056).
I did an iodine test with 10 minutes left (in the 60 min rest) and had some black stuff settle out but it was all brown at the 60 minute mark so thought everything was converted. This is the first time I’ve tried this.
I decided to let it rest another 15 mins and the gravity went up to 1.048. Hrm… Let it rest again for another 15 mins and the gravity went up to 1.052. Ok so things appear done via Iodine, but they must not be. I’m getting closer to my target so I let it rest to 100 mins and gravity went to 1.055. I’m using a refractometer and letting the sample cool down before checking. Even checked it five minutes later thinking maybe the temp was throwing things off but it comes up the same.
After 115 mins @153 I’m up to 1.057.
I’m using an Anvil Foundry with the recirc pump and brewing in a bag. Is this typical of a mash rest? I’m going to let it go another 15 mins and see where it ends up. I’m guessing it should flatten out at some point, but not exactly sure what’s going on.
update: After 130 minutes at 153 I’m up to 1.060. I didn’t really want an 8% beer but that seems to be where things are headed so turning temp up to 168F for mash out. I should probably post my grain bill in case it matters (using 8 gallons strike water for a no-sparge batch):
- 12# pale 2row
- 1/2# crystal 120
- 1# Chit
- 2 handfuls rice hulls
- 1/2 tsp of Amylaze enzyme