RIMS declining efficiency

Question

RIMS declining efficiency

Icebreaker

2019年11月4日 15:42

For many years, I was getting efficiency at about 81% after backing into the numbers with Brewers Friend doing simple non-recirculated infusions at 2qt per lb with continuous fly sparge.

About a year ago, I built a electric RIMS 240 volt, 5500 watt, PID controlled system, so that I could do some step mashes and manage temps better. I like the set up, but my efficiency has gone down to 61% with continuous recirculation and the RIMS firing as needed to hold the desired temp. I am alright with poor efficiency as long as I have predictable results.

Yesterday I brewed a hefe, that I have done many times. The change was to a step mash starting with 15 min at 111°F, then 15 min at 122°F, and then 30 min at 150°F. This was all stepped with the RIMS. Before sparging, I did a mash conversion test with iodine and it showed that it was all converted. Did a normal fly sparge. Efficiency on this batch was 50% which means I will have very weak beer, OG 1.037. My single temp RIMS target was 1.042, which I have previously achieved, and my no circulation infusion would have been 1.055.

I was wondering if anyone else using a RIMS was seeing similar results. I am wondering if the heating element is killing off the enzymes during recirculation, but if that were true my starch test should have shown plenty of unconverted starches. I am confused by my declining efficiency.

Thoughts are welcome.

Topic rims process homebrew efficiency

Category Mac

Evil Zymurgist · Accepted Answer · 2019年11月4日 15:42

RIMS can denature your enzymes.

The biggest risk with a RIMS is the small volume or wort that is heated at a time. The result is often the enzymes are denatured because of the contact with the heating element.

This can be limited or even completly overcome by moving the wort faster through the RIMS. Also the temp probe for the heating element should be as close to the heating element as possible and use a short delay on the PID. Then its much easier to not allow the wort in RIMS heater to hit denaturing temperatures.