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Madman's Mosaic

Ever since I first tasted Adnam's Mosaic a good few years ago I've promised myself that I'd brew a single-hop Mosaic ale in that style and finally after far too long, today is that day.

Yeast preparation

I built a 1.5 litre starter of my Brewlab Yorkshire strain for this brew. 500ml goes back into the fridge in a jar for next time and 1 litre stays in the flask for the brew.

I remembered to add a couple of drops of the antifoam to keep this starter in check and as such had no worries about using my smallest 2 litre flask for the starter.

72 hours after putting the starter on it was done and I separated off the 500ml that I'll keep behind.

Brew day

Here's the recipe. I'm aiming for a bit lower OG this time at 1.040 because my fermentations tend to finish low at around 1.005 and that means it's rather too easy to end up with a beer around 5% when the OG is only in the mid 1040s. I'd rather drink ales around 4.5% so I'm dropping the OG a little in the hope that will work.

Recipe Specifications
Date: 24 December 2022
Batch Size (fermenter): 24.00 L   
Estimated OG: 1.040 SG
Estimated Color: 11.9 EBC
Estimated IBU: 37.4 IBUs
Brewhouse Efficiency: 75.00 %
Est Mash Efficiency: 75.6 %
Boil Time: 60 Minutes
Water profile: Ca:90 Mg:12 Na:9 SO4:110 Cl:108

Amt         Name                                             Type          %/IBU    
29.39 L     Tesco Ashbeck                                    Water         -       
3.70 g      Calcium Chloride (Mash)                          Water Agent   -       
2.70 g      Gypsum (Calcium Sulfate) (Mash)                  Water Agent   -       
2.40 g      Epsom Salt (MgSO4) (Mash)                        Water Agent   -       
0.80 ml     Lactic Acid (Mash)                               Water Agent   -       
4.000 kg    Weyermann Eraclea Pilsner Malt (4.5 EBC)         Grain         92.5 %   
0.150 kg    Weyermann Munich I (14.0 EBC)                    Grain         3.5 %   
0.100 kg    Crisp Medium Crystal (240.0 EBC)                 Grain         2.3 %   
0.80 g      Calcium Chloride (Sparge)                        Water Agent   -       
0.60 g      Gypsum (Calcium Sulfate) (Sparge)                Water Agent   -       
0.50 g      Epsom Salt (MgSO4) (Sparge)                      Water Agent   -       
0.20 ml     Lactic Acid (Sparge)                             Water Agent   -       
0.075 kg    Corn Sugar (Dextrose) [Boil] (0.0 EBC)           Sugar         1.7 %   
7.00 g      Columbus/Tomahawk/Zeus (CTZ) [14.30 %] - Boil 60 Hop           11.8 IBUs
22.00 g     Mosaic [11.90 %] - Boil 10.0 min                 Hop           11.2 IBUs
1.00 Items  Whirlfloc Tablet (Boil 7.0 mins)                 Fining        -       
32.00 g     Mosaic [11.90 %] - Boil 5.0 min                  Hop           9.0 IBUs
46.00 g     Mosaic [11.90 %] - Boil 2.0 min                  Hop           5.5 IBUs
1.0 pkg     Brewlab Yorkshire (Brewlab #Yorkshire)           Yeast         -       

Mash Schedule: Single Infusion, Full Body
Total Grain Weight: 4.670 kg
Name     Description                     Step Temperat  Step Time     
Mash In  Add 24.39 L of water at 71.3 C  66.0 C         60 min        

Sparge: Dunk sparge with 5L

I added a very small amount of some crystal that I had left over to compensate for the fact that I'm using a pilsner malt here because the original Adnams beer is brewed with 100% pale malt. Hopefully it'll add just a little more depth to the malt flavour without being too noticeable.

It won't be news to all of you that have used mosaic before but the smell is incredible! I'm also using Columbus (CTZ) for authentic American bittering.

Brew day was another easy one with nothing much to report. I did notice that the pre-boil gravity was 1.036 rather than the expected 1.037 so I decided to add an extra 75g brewing sugar during the boil to add one point to the OG. I know it's not much but I did want to hit the 1.040 target and I know that during the boil I will add 3 points to the measured gravity.

OG was indeed 1.040, exactly on the target. As expected the colour is slightly darker than the previous Punk'd Up that I brewed. Just over 24 litres were collected after cooling and I set the brew fridge to 19C for the fermentation, pitched the yeast immediately and was pleased to see bubbling by the end of the day.

The sample jar tasted lovely, much better than the somewhat murky looking photo above. I think something's off with the white balance on that photo.

Kegging day

I kegged this one after 3 weeks in the fermenter.

The FG was 1.006, still broadly in line with what I always get from this Brewlab Yorkshire yeast which tells me that despite so many re-uses that I've lost count it is still performing strongly. The yeast had cleared up nicely in the fermenter and I transferred it to a pre-purged corny keg and 4 bottles. The keg was fined with a sheet of leaf gelatine dissolved in 200ml of boiled water that had cooled to 65C. I set the keg at 15psi where it will carbonate and condition for at least the next two weeks.

Tasting notes

I'm really pleased with how this came out. The flavour is almost identical to the Adnams ale and makes for a very drinkable beer. Perhaps the only cricticism I could level at it is that, like any single hop ale, it can get a bit boring after a few glasses. I think that generally speaking I prefer an ale to have a blend of hops to increase its complexity.