Oca “Broyhan”

For awhile now I’ve mulled over the idea of making a potato beer, which is nothing innovative (sweet potato beers are common enough), and the idea itself came out of a Ron Pattinson post on German Broyhan brewed with potatoes. Bolivia being the land of potatoes, I’ve had my eye on using oca for this beer, a skinny tuber about the length and width of fat thumb and absolutely delicious when sliced lengthwise and thrown right on the grill–sweet and soft inside, with a nice crunch on the outside. And not to forget, they are a beautiful potato to look at. The downside, of course, is that it is also highly seasonal. So, when oca finally showed up at the end of April in the local markets, I immediately took home a kilo and drew up a quick recipe riffing on the historical Broyhan recipe.


A kilo of oca brought home from the market.

At the time, Munton and Fison Ale Yeast was the most neutral strain I had on hand, so that’s what I went with. This was a very lackadaisical brewday by my own standards, doing a 4 liter brew-in-a-bag, “milling” 650g of pilsner malt in a food processor, shredding 400g of oca by hand, and adding a pinch of Cluster hops at 60 minutes into the boil. A kind of rainy day project.


Shredded oca in the pot, ready for gelatinization.

First I boiled the shredded oca for 10 minutes to ensure full gelatinization and then diluted with cooler tap water and a squeeze of lemon (tap water is extremely hard and alkaline here) and mashed in at 66° C and held it for an hour. The mash being full of shredded potato, I put the bag in a colander and rinsed the mash to pull off as much residual sugar as possible. Again, I still don’t have a way to measure gravity at home, so this should have been around 1.045, but I’ll never really know.

Trying to pay some tribute to the English ale yeast influence, after two weeks in primary I racked the beer to a 5 L mini-keg and one small 330 mL bottle. The mini-keg yields somewhat flat beer with a massive head fairly consistently, so it looks great and tastes a bit more watery than I’d prefer. Here’s what the results looked like coming out the bottle.


Oca “Broyhan”

In the end, a deliciously mild session ale. Lightly sweet, herbal and spicy on the tongue from those Clusters, the character of this beer deepens as it warms. Pear flavors and aroma jump out, especially when this beer was very fresh.

I’m not sure what the logistics of brewing with shredded potatoes would look like, but this would make for a great cream or blonde ale within a brewery trying to pay tribute to Bolivian culinary traditions without letting novelty get in the way of quality. Certainly calling it a “Broyhan” is a stretch, but perhaps with a Kölsch yeast and some other tweaks one might at least reference the historical beer without it being complete imaginary leap.

  1. Ivo Foianini said:

    Bud, hat’s off to your “experiment” with oca! It appears that you have something going there, but as you mention, some additional ingredients may have been necessary to add some character to your beer. You mention that Bolivia is that land of potatoes and I read somewhere that there are more than 1000 different kinds in the country (probably more).

    That would be an excellent business idea for a craft brewery down there, brew only beers made with potatoes as your primary ingredient and customize them accordingly with other local ingredients (canha de azucar, melao, as sugar source maybe?).

    Nice to see you’re still at it…cheers!

    • I’m not sure you’d want to use potatoes as the primary fermentable, but as I found out in brewing this, it adds some unique character when used as a sizeable specialty fermentable.

      I agree that the focus on local ingredients would be a great business idea, and you could do it without falling prey to novelty as well. Likewise,I’ve come across some interesting native hops such as “Mapuche” hops from Argentina. Also, I’ve used chancaca and miel de caña for the last couple years with great success. Both add lots of rum and molasses character in the way that candi sugar and candi syrup do.

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