When Get ‘Er Brewed offered members of the Homebrew Forum the opportunity to get free Fermentum Mobile liquid yeast in exchange for an online review, I jumped at the chance despite never having used liquid yeast before.
Having made a very successful American Wheat Beer previously using the popular dried yeast US-05, I was interested in using a yeast formulated specifically for American Wheat Beers. The Fermentum Mobile Kansas Ears yeast looked to be perfect, with the recommended styles for the strain being American Wheat and Cream Ale.
I modified the recipe from Greg Hughes’ Home Brew Beer book (my bible) switching the Citra for 100g of Mandarina Bavaria, a hop which I was sure would be suited to the beer style.
After a bit of a debacle getting my delivery (being paranoid about the ice pack melting I had a 60 mile round trip to the Parcel Force depot in Perth at 7am on a Saturday morning – I’m still baffled as to why they don’t have a depot in Dundee), my yeast arrived without issue. Get Er Brewed’s ice pack was still frozen after 3 days in transit so I could be sure that the yeast had stayed fresh.
This was where it became daunting – what do I do with a liquid yeast? The instructions said I could pitch directly into my wort, but recommended making a starter. What would I do? I decided after some online research that I should make a starter. The Fermentum Mobile website gave very good instructions on how to make a starter, and my book also gives instructions so I gave it a go.
I went to Holland and Barrett one lunchtime and bought a jar of Malt Extact. The Thursday before brewday (the instructions state to build the starter for 48hours) I boiled 120g of malt extract with a litre of water for 15 minutes, cooled it in the sink and decanted into a 1.75L Coke bottle. I added the yeast, put on the cap, shook vigorously, unscrewed the lid slightly and left in the corner of the kitchen. Every so often, I would screw the lid, give it a shake and a squeeze. I assume opening and shaking releases CO2 pressure and introduces more oxygen for the yeast to feed on – it was a tip from the Forum.
My next decision was how to pitch. I had 2 options – I could stick it in the fridge overnight so the yeast drops, pour off the starter wort and pitch the yeast cake; or I could pitch the whole lot, malt extract and all, into my beer. I’d read that at low levels like 1L in a 20L brew there would be no adverse impact on flavour, especially in hoppy or dark beers, so I though “what the Hell?”and decided just to bung the lot in!
Brewday itself went off without a hitch. I hit my target Starting Gravity, bitterness units (28 IBUs), and managed to transfer just short of 23L into my Fermenting bucket. Then I learned a valuable lesson. I shook my starter bottle quite vigorously to mix in the yeast that was stuck to the bottom of the bottle, opened the bottle and the starter jumped out of the bottle! I managed to contain it quite well but still ended up with a couple of hundred mil on the floor! I suppose you wouldn’t shake a bottle of Coke so why would you shake a yeast starter?
I then left the bucket in my brew cupboard to ferment for 2 weeks, primed and bottled, left 2 weeks to carbonate and 2 weeks to condition.
100g of Mandarina Bavaria was perhaps slightly too much, so the wheat flavour doesn’t come through as much as I would have liked. The yeast attenuated well (78%) and it certainly looks like a Wheat beer, and has given a nice clean/smooth flavour, which is what you want from an American Wheat Beer. The hops don’t give the big orange/mandarin flavour I was expecting (although it does have a bit of mandarin type aftertaste), but the big grapefruit flavours that I am detecting from the hops is really nice and works very well with the American Wheat.
This was my first experience with a liquid yeast, and it was a good one. Making a starter was nowhere near as scary as I thought, the yeast gave me an attenuation better than all bar one of my previous brews, and gave the flavour profile I expected from an American Wheat yeast. I won’t buy liquid yeasts for every brew (I like US-05, M44 and M54 a lot for IPAs and Steam Beer), but for speciality beers I will definitely give liquid yeast another go, and I think Fermentum Mobile will be my go-to brand.