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Trial Number 5

Client Number 153

Project Number 13

Trial Purpose:

To test the efficacy of safer alternatives to caustics in removing encrusted yeast and hops from stainless steel coupons.

Date Run:

12/16/2024

Experiment Procedure:

Stainless steel coupons were chosen and had their initial weights recorded before beginning the 'brewing' process.  To begin the 'brewing process' a slurry of 1.5 lbs of dry malt extract and warm water was made and added to 2 gallons of boiling water in the brewing pot.  An entire packet of hops was then added to the brewing pot and continued to boil for ~1 hour until wort was created.  The wort was allowed to cool to room temperature before transferring it into the plastic fermentation bucket.  6-7 grams of dry yeast was rehydrated with a small amount of warm water, and was left to rest for 5 minutes.  The dry yeast mixture was then added into the fermentation bucket (without stirring).  The coupons were hung in the fermentation bucket with fishing line so that the bottom of each coupon sat just above the wort level.  The fermentation bucket was covered and left to ferment for 72 hours, checking for yeast activity every day.  Once the coupons were removed, they were baked in the oven at 250F to fully solidify the yeast and hops soil to the surface.  At this point, the dirty weights of the coupons were then recorded.

To clean, the coupons were subjected to 10 minutes of immersion in their respective cleaners with a stir bar set to 300rpm.  After cleaning, each coupon was rinsed with tap water for 10 seconds.  After allowing the coupons to air dry, the clean weights were recorded.  

Trial Results:

Cleaner Temp Initial wt of cont. Final wt of cont. %Cont Removed % AVG
Vidivis ICT 2% Unheated 0.0057 0.0010 82.46 75.55
0.0089 0.0020 77.53
0.0015 0.0005 66.67
Virdivis ICT 2% 120F 0.0019 0.0003 84.21 85.67
0.0116 0.0016 86.21
0.0112 0.0015 86.61
BevSafe Line and Tank Cleaner 2% Unheated 0.0043 0.0004 90.70 91.91
0.0094 0.0003 96.81
0.0051 0.0006 88.24
BevSafe Line and Tank Cleaner 2% 120F 0.0127 0.0000 100.00 95.59
0.0088 0.0004 95.45
0.0046 0.0004 91.30

Success Rating:

Results successful using TACT (time, agitation, concentration, and temperature, as well as rinsing and drying) and/or other cleaning chemistries examined.

Conclusion:

Virdivis ICT 2% was successful in removing encrusted yeast and hops when subjected to heated immersion, but gave an inconsistent performance when subjected to unheated immersion.  The BevSafe Line and Tank Cleaner 2% was successful in removing encrusted yeast and hops with unheated immersion and highly successful using heated immersion at 120F.

Next steps for testing are to test the Virdivis ICT at a higher concentration and testing the 2% concentration with a longer cleaning time.  The BevSafe Line and Tank cleaner can be tested at a lower concentration.

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