Sunday, 26 August 2018

Broad Bean Saison

On my one of the few things that will overwinter on an allotment in the UK is broad (fava) beans. A variety called "Sutton" was grown on mine, and I ended up with a couple of kg of the beans, which were blanched and then frozen. They then remained in the freezer for a year, taking up space.

They probably had been left on the plant a bit long and had got quite large and starchy. I remembered that one of the things a turbid mash is supposed to do is to contribute starches for microbes. The idea behind this being that sacc can't metabolize the starches but other bugs can.

 Someone has hypothesized that Brett doesn't really need much left behind because it can metabolise other stuff, so turbid mashing is really for other bugs, so what I'm doing doesn't make a huge amount of sense, but still.

I wanted to have another go at a saison with brett and thought the beans would be a rustic addition to a rustic beer.



I must say I was slightly inspired by CJJ Berry's excellent wine making book where the broad bean wine is celebrated as surprisingly good.  He suggests boiling the beans to extract whatever they contribute, but he suggests not letting the skins split to help the wine clear later. I'm not sure whether this is to stop protein or starch getting in the wine, but I decided I wanted both in my beer, so mashed the beans periodically with a potato masher. 

The 500g of beans started out a lovely green in 2 liters of water. At the end of an hour or so there was almost zero fresh bean aroma left and I had a grey looking sludge. This set in the fridge to a grey jelly, which hopefully means the beans had gelatinised. I froze it to preserve the goodness until I came to brew my saison.

The frozen block of beans was added to the inside of my BIAB bag, and swirled in the mash water while it heated. It surprised me how long it lasted in 70 degrees C water and actually it meant the mash water climbed all the way to 72 before it had melted the block. Adding a kilo of barley malt to the mash lowered the temperature to 68-9 degrees.

The recipe for this was 64% barley malt and 36% unmalted boiled frozen broad beans (by extract). I guessed that the extract potential of a broad bean was 1.038 which is the same as wheat as suggested in "designing great beers" by Ray Daniels. I use custom "software" to design my recipes in the form of a spreadsheet based on information from this excellent book. I wanted a very low gravity saison, I shot for 1.035 anticipating I might come a little short and 1.030 wouldn't be the worst thing in the world.

For this one I wanted to adjust my water. Bristol water is generally good for medium dark beers (bitters?). For lighter recipes, I generally have to lower the PH using a bit of HCL, and, either gypsum or calcium chloride depending on the desired sulphate-chloride ratio. The use of HCL to lower the PH normally means it is  difficult to get chloride levels bellow 150ppm-ish. For this recipe it didn't really matter and I hoped to achieve the following profile (ppm).

 
Ca Mg Na Cl SO4 HCO3
98 4 25 147 144 0.6


I'd read on a forum thread, where a bloke reports on malting lentils, that he got an iridescent shine on the bubbles on his brew. I sort of noticed the soap bubble like effect in the mash, but once the boil began the bubbles became much tighter and more matt tan. The photo below is after transfer to the fermentation vessel.



I take gravity readings at the start of the boil and then calculate what volume to brew to to get required gravity. The wort was a normal looking colour, not too grey.



This one was at 1.024 for 11L of collected wort. I chose to boil down to 9L to get final gravity of about 1.030. The wort actually boiled down much faster than expected so I had to add water to the fermenter to top up. It also darkened quite a bit. (See photo above above). This suggests the actual extract potential of broad beans is almost zero.

I used 10g of northern brewer at 60m mins for 21 IBU and then 10g of my allotment hops (mainly fuggles with a little bit of EKG) at 30mins for a further 3 IBU. This was more a romantic gesture as the beans and hops would have grown side by side last season (or saison?). No late hops for this one. The BU to GU ratio was 0.8. Refreshing but not too mouth stripping.

The wort was transferred to a brew bucket and a half package of mangrove jacks Belgian ale was pitched after an overnight cool. The yeast had been hanging around for a while (open but pegged shut). The brett I got originally  from some bruxellensis dreggs  (or was it orval? Who knows. Oops.) was pitched after 1 or 2 days. After a week or so I pitched burning sky's "saison a la provision" dreggs. I wasn't sure if I'd get much lacto expression due to the hopping.

 The beer was excellent, It was a lovely hazy yellow, the brett was very subtle and the lacto was non-existent. It just had a very bright slightly winey pale bright light flavour. This was an excellent table beer. I'm not sure what the beans really added, but suspect some of the clean fresh flavour might be from them, as well as a possible contribution to the body, although I may be completely deceiving myself based on psedo-scientific predictions about what the beans should do. I think because this was so low gravity the saison yeast was not so phenolic as it would be in a higher gravity example, which I much preferred.



One criticism would be that the hop character was a bit dull and one dimensional, a sort of slow lump of dreary just-bitter. If I were to re-brew, I would probably do either a large late addition of some floral noble hops, or I think it would work to just go wild and stick in something daft like galaxy in a large dry hop.

Excellent low gravity beer.

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