Honestly, you do not need a "currency" if your using Mi'ta tax system (a form of tax where one's tax is payed in labor to the government). As you are requiring the tax to pay provide labor to the government in liue of any other currency (you have none of that) or commodity tax (i.e. the government requires so commodity for your production of commodities). Since you're requiring a set time of service to the common good, your tax is a tax on labor (labor is a commodity) and for every 14 billable periods in a week, someone is required to work a percent of billable periods for a community service. Societies like this are rather rare and really, only one significant civilization used this system, the Inca, but they also imposed a Commodity tax on agriculture (and Mi'ta was only for physical labor like construction or military service and then only issued to males and only when required.).
In Inca society the Emperor (Sapa Inca) was seen to have a duty to improve the lives of the people by using tribute offered through fuedal exchanges to re-invest in projects to improve communities. Agriculture levies were stored in government storehouses to be used for armies and in time of greater need, while Mi'ta labor was used both to ensure the army had the manpower and develop the infrastructure (including the roads, store houses, and terraced farms that would then be worked by the laborers). While there is evidence that the Incas did have currency (in the form of Ax Monies, ax shaped metal trinkets that seemed to easily denote a value of some kind and may have contained religious significance) and their are some arguments that their complex accounting system might have also been a currency (though no one really knows what the hell the knotted values denote as a standard unit of measure), there is little evidence that they used these measures for internal trade, but rather external trade.
Your next problem is your choice of commodity is a perishable good that's easy to counterfeit. For a council that is aware of inflation, this is ridiculously stupid on their part. The reason why counterfeiting currency is such a huge deal is that inflation occurs when there is too much currency is available while there is too little demand for it. Almost every currency is limited by it's issuer's control over the product, and save for feudal Japan, almost all societies used a mineral/metal commodity as opposed to a agriculture commodity because the latter is super-easy to counterfit. It literally grows on trees. Japan got away with it because Japan is actually agriculturally limited due to it's terrain, so rice was basic enough to back coinage as a value.
It's also important to understand that a currency is not a commodity, but a physical representation of a difference in value between two distinctly nonidentical things. To use the common phrase, money is literally comparing apples to oranges:
Suppose you're a farmer and you have a bushel of apples and you want to trade with your neighbor for a bushel of oranges. Both sides want a fair deal and you insist that you can't give a whole bushel of apples because you need to keep some for rakes so you can grow more apples. But your neighbor doesn't want to give you a bushel of oranges because he needs rakes to make more oranges too. The logical solution is to trade rakes for apples and oranges. Suppose you use 5 rakes to produce a bushel of apples, and your neighbor used 4 rakes for a bushel of of oranges. You can offer to give the farmer 4 rakes for his bushel and you will give him five bushels for a rake. Now you're rakes are currency as they can show a difference between two things that are literally apples and oranges (and if you realize you have to change your apples into rakes before you can change your rakes into oranges, so you make a promise to by bushels of oranges at a later date when you can get your apples turned into rakes, congrats, now you have a futures market).
Now this is increadibly simple because you have to ask how do you value rakes to apples? And the metal in the rake and wood in the handle? And the manufacturing speed of rake production? And the rake maker wants a chicken dinner. The problem of the barter system is that comodities exchanges are difficult without some common base item. To solve this, a market may standardize one unit of commodity to another (Like how we said apples equals rakes), but since rakes require metal and wood to make, you need to standardize rakes to metal and wood, and as the product is broken into constituent parts, the product can be removed as you now have a basic commodity exchange developing and the more basic a product comes, the more you can get to a currency commodity: a commodity that is ideally simple in it's base parts, finite or reliably replacable, standardized in size, and universally important to a wide group of consumers. Like I said, Rice was this for Japan in that it could represent useful land. There was a finite supply of rice producing land, you could reliably produce rice, you could put it into standard measuring containers, and everyone needs to eat food (and it's cheap food at that) so it back the Yen, giving it purchasing power. The Yen it's easier to carry 500 yen ($5.00) than it is to carry 500 yen worth of rice. In Europe, where there was more reliable farming land, they used precious metal (Gold, silver, bronze) because metals melt with high heat and could cast into numerous shapes. In fact, most coins weren't just representation of the value of a precious metal but actually contained the exact value of metal. A Spanish Dollar (aka a Piece of Eight or Peso) was worth it's weight in silver because a Dollar was made by molding silver into a circle shape. It was very much literal.
And why we still care about the Piece of Eight is that it's the first world currency because The Spanish Empire was involved in so many economies all over the world, including the Americas and Far East Asia. Nations without access to reliable metal sources could accept Pieces of Eight and then melt the coins and mint their own money... this practice still exists in the form of Pegged currencies where a nation will not use a commodity to give value to their currency but will control the ratio of their currency with respect to a very important currency of another nation. Post-World War II Japan switched the Yen from it's backing, cause it's commodity production had been destroyed, to keeping it in a one to one ratio with the USD (and today it's more reliable in a 1:100 to USD... but it's not really pegged).
These days this is controlled by buying back their own currency or selling the currency backing it and why we have exchanges. No major currency uses metal backing but is fiat (The USD is the dominate world currency and is commonly pegged to because of this. The USD is backed by "The Full Faith and Credit of the U.S. Government" which has a reliably stable ecconomy that since World War II dominated the world economy. You don't have to deal with the U.S. economy at all... but it's rather hard to do. This is why the U.S. now favors economic sanctions as a punishment before war, as your currency might not be pegged to USD, but other important markets are... and they won't take your monopoly money because the U.S. won't buy it with it's dollars, so they won't buy it with there Dollary-doos... which means you can't trade your goods because you can't get a reliable exchange for them and with enough time, even your own people will abandon you and your policy that caused this problem because they can't feed their families. It takes longer than a war, but the plus side for the bigger market is they don't have to send droves of people into your nation to get killed and are more than happy to watch your government collapse from within.
For a TL;DR version, don't use commodities for a currency, but rather think of a currency as a coupon for free commodities from the government supply. One unit of currency should be worth some unit of measure of beans. Inflation occurs when there is more supply of currency but the commodity supply is stagnet, thus the demand for currency weakens while the demand for product does not. The product makers can then charge more for the product because they can get more currency... but everyone else can as well. Typically centrally controled markets tend to respond by mandating product prices be controlled... but really they need to stop issueing currency and release more of it's backing power to get the ratio of available currency to product back into something nice. This is what causes most hyperinflation scenarios and currency collapses, such as Venezuala's ongoing economic troubles, and North Korea's currency nearly getting placed by the confectionery treat of Moon Pies as the population's preffered medium of exchange (and De Facto Black Market Currecy). Yes, a pastry was a more reliable currency than a North Korean Won.
