Barm

Preparation

1. Step 1

   Stir together the flour, water, and seed culture in a mixing bowl (you can discard the remaining seed culture or give it to a friend to build into his or her own barm). Make sure the seed culture is evenly distributed and all the flour is hydrated. It will make a wet, sticky sponge similar to a poolish (see page 232). Transfer this sponge to a clean plastic, glass, or ceramic storage container twice as large as the barm. When transferring the barm into the container, repeatedly dip your hand, spatula, or bowl scraper in water to keep the barm from sticking to it. Cover the container with a lid or plastic wrap and ferment at room temperature for approximately 6 hours, or until the barm is bubbly. The plastic wrap will swell like a balloon, as will a plastic lid. When this happens, open the lid or release the plastic to let the gas escape (try not to breathe it as it escapes—the carbonic gas mixed with ethanol fumes will knock you across the room!). Replace the cover and refrigerate overnight before using. The barm will be ready to use the next day and will remain potent for 3 days. After that, or if you use more than half during the next 3 days, you will need to refresh it as described next.

2. Refreshing the Barm

   Step 2

   The standard refreshment for barm is to double it at least. However, you can also quadruple it, as the organisms in the barm are capable of feeding on a large refreshment and converting it into starter. I double the barm at each feeding if I want a very sour bread, but I triple or quadruple it when I want a less sour flavor. Remember, it takes longer for the bacteria to work than the yeast, so while a larger feeding dilutes both the bacterial and the wild-yeast communities, the yeast bounces back faster than the bacteria, creating a strong, but less acidic, leavening sponge. Eventually, the bacterial fermentation does catch up, by the second or third day, and the sponge becomes quite acidic and sour (with a pH level of about 3.5).

   Step 3

   It is important to understand what happens when you refresh the barm. After 4 to 7 days, the acids and protease enzymes in a barm that has not been refreshed break down the gluten, turning what was at first a strong, stringy sponge into a protein-weak, potato-soup–like consistency. There are still plenty of live organisms to leaven and flavor bread, but they will make a flaccid dough. For this reason, it is advisable to feed your barm 3 days or less before you plan to use it (ideally, the day before). If you have a lot of barm but haven’t fed it for a while, discard all but 1 cup and refresh it with 4 cups of flour and 2 1/2 to 3 cups water, stirring until all the flour is hydrated.

   Step 4

   If you have been using and feeding your barm regularly, you do not necessarily have to discard any. However, what you do not want to do is, for example, use 1 cup of barm from your supply to make some bread, then refresh the remaining barm with only 1 cup flour and some water. You must always at least double the remaining barm. You can do this by either throwing or giving some away before you refresh it, or using up more before refreshing it (remember, you have a 3-day window before you need to feed it again).

   Step 5

   If you do not plan to use the barm for a while, do not throw any away until you plan to refresh it again, and follow the guidance given above to refrigerate or freeze it in a tightly sealed container. Since you do not want to freeze a glass or ceramic container, you should transfer the barm to a zippered freezer bag that has been misted with spray oil (allow enough room for expansion and gas development).

   Step 6

   Use high-gluten flour for the refreshments (except in the case of a rye barm), as it has more gluten than in bread flour to withstand the acid and enzymatic degradation.

   Step 7

   You can refresh in two ways. One is to weigh the amount of barm you plan to refresh and the other is to eyeball it. I use both methods and find that as long as you stay in the doubling to quadrupling ballpark, you will have no problem keeping your mother strong, active, and clean tasting. By clean tasting I mean that no off-flavors develop, such as a musty or cheesy flavor caused by overfermenting at warm temperatures or by leaving it out too long. This allows unwelcome bacteria to join the party or for the yeast to create too much alcohol, resulting in what we think of as a yeasty flavor. The flavor is a combination of alcohol and glutathione, an unpleasant-tasting amino acid released by yeast as it dies.

   Step 8

   The weighing method is simple: Weigh the barm and calculate how much flour and water it will take to double, triple, or quadruple the weight (the easiest way is to figure equal parts water and flour). Thus, if you plan to refresh 1 pound of barm, you can build it to 2 pounds by adding 8 ounces each of flour (1 3/4 cups) and water (1 cup); or you can quadruple it by adding 1 1/2 pounds flour (5 1/4 cups) and 1 1/2 pounds (3 cups) water. The larger the refreshment, the longer the fermentation time, usually 4 to 6 hours, depending on the size of the refreshment and how cold the barm was when you started. If you are using a cold barm just out of the refrigerator, warm the water up to about 90°F to compensate and to hasten the onset of fermentation. Never let the starter actually be warm, however. It is best for the organisms we want to cultivate, the lactic- and acetic-producing bacteria, if the starter ferments slowly, between 65° and 75°F, or at room temperature.

   Step 9

   When the starter is bubbly and foamy, put it in the refrigerator overnight before using it. Technically, though, you could begin using it as soon as it foams up, but I wait for the overnight development because I believe it gives the bread more complexity of flavor. Either way, with a ripe and ready barm, you are ready to move on to the next build.

3. Commentary

   Step 10

   Opinions are divided as to whether the pineapple juice is really necessary after Phase 1. It probably is not, but it won’t hurt to use it during Phase 2 and may, in some instances, serve as insurance against the appearance of leuconostoc bacteria.

4. Step 11

   The full flavor of the barm will not develop until it has been refreshed 2 or 3 times over a 2-week period, during which time the organisms indigenous to your region will gradually take charge of it. (This is why a starter made from a seed culture imported from Egypt or Russia will, over time, produce bread that tastes like a starter made locally from scratch.) When the barm reaches its peak flavor, you will be able to maintain that flavor with periodic refreshments. However, you can begin using the barm the day after it is made. The leavening power will be strong from the first, since the wild yeast ferments the barm at a faster pace than the bacteria produce their flavorful acids.

5. Step 12

   If you want to save the barm but do not plan to make bread for a while, you can refrigerate it for at least 2 months in an airtight container, and then refresh it by discarding all but 1 cup and building up from there. Or, you can freeze the barm for up to 6 months and then defrost it in the refrigerator 3 days before you need it. When it has thawed enough to use (the next day), discard all but 1/2 cup and refresh as described at left. Then refresh again the next day, building back to about 4 to 6 cups barm. The following day you will have a strong, ready-to-use barm. Of course, you still have 2 more days of dough building to accomplish, as described in the formulas.