Comparing Different Mashing TechniquesRIMS vs. HERMS vs. Single Infusionby: Harold J. Gulbransen & Bob MacKay

Is there a difference between HERMS & RIMS mashing?

• HERMS = heat exchange recirculating mash system

• RIMS = recirculating infusion mash system• Advantages over single infusion mashing

– Clearer wort– More precise temperature control– Perform more complex mash schedules

Is there a difference between HERMS & RIMS mashing?

• Potential disadvantages– Requires a pump so added cost– Scorching the wort is possible with RIMS if the

pump fails– No scorching with HERMS as the wort never

contacts direct heat

Controlling the Variables

• Brewed a Bock Bier to feature it’s malty character

• Same water profile – carbon filtered SD water• Same malts • Same sparging technique [batch sparge]• Same mash tun, kettle and chiller• Pitched same volume of yeast and feremented

all beers in 10 gallon corny kegs [same geometry] and in the same chest freezer using a Johnson Controller

Recipe6.0 gallons32.5 IBU 75 min boil 18.7 SRM

54.2% Munich Malt 10L [Briess] 8.00 lbs

32.2% Pilsner Malt 2L [Briess] 4.75 lbs

6.8% Melanoidin 35oL 1.00 lbs

5.1% CaraMunich 0.75 lbs

1.7% Cafafa II 0.25 lbs

Rice Hulls 1.0 lbs

Carbon filtered SD water 22 qts [1.5 qts water/ 1 lb grain]

Sparge 18 qts 170 F [acidified w/ Phosphoric acid]

Hops: 25 gm Magnum 11.0% aa 60 min

25 gm Vanguard 4.7% aa 10 min

Yeast: White Labs WLP 810 [SF Lager] – 200 ml of yeast slurry

Fermentation temps: 50oF

Packaging: kegged & force carbonated – Beer Gun to fill Bottles

-10 0 10 20 30 40 50 60 70 80 9070

90

110

130

150

170

190

210

HERMS & RIMS Mashing

Strike WaterGrainHERMSRIMS

Time [minutes]

Te

mp

era

ture

[

°F ]

-10 0 10 20 30 40 50 60 7070

90

110

130

150

170

190

210

Single Infusion Mash

Strike WaterGrainMain Mash

Time [minutes]

Te

mp

era

ture

[

°F ]

Wort Aeration with Oxygen & a SS Aeration Stone

Next day: Single Infusion Mash

Thanks to Patrick

Temperature control during fermentation

Fermentation in a chest freezer with a thermostat

Results:

  HERMS RIMS Single Infusion

Pre-Boil Gravity 1.046 1.044 1.046

Pre-Boil Volume 8 gallons 8.4 gallons 8.1 gallons

Volume after boil 6.5 gallons 6.6 gallons 6.7 gallons

OG after boil 1.062 1.062 1.058FG after feremntation 1.020 1.020 1.021

Evaluation of Head RetentionTime = 0 min.

Evaluation of Head RetentionTime = 2 min.

Evaluation of Head RetentionTime = 3 min.

Evaluation of Head RetentionTime = 8 min.

Evaluation of Head RetentionTime = 20 min.

Evaluation of Head Retention

• Best to Worst:– HERMS– RIMS– Single Infusion Mash

Best Quality Head -RIMS – fine tan bubbles

Flavor Profiles

JoAnne found HERMS the best tasting

Slight metallic flavor with RIMS beer

Single infusion had least body and was thinner than the other two.

QUAFF Consensus? Let’s vote

Special Thanks to Bob MacKay

Was this helpful to you when considering what Mashing technique you will employee in the future?