If you shop at certain local farmers markets, you may have noticed that some of Weirauch Farm & Creamery’s cheeses haven’t been available for a number of weeks.

Lucky for us all, that’s changing.

This weekend, the Penngrove-based farm should have a selection of fresh cheeses, including Doubloon, aged just one week; Tomme Fraiche, aged two weeks and, maybe, a sheep’s milk Tomme Fraiche, along with some other fresh sheep’s milk cheeses, including Primo Fresca, literally, “first fresh,” the first sheep’s milk cheese of the year. There may also be sheep’s milk ricotta. To snag these cheeses, you must get to the market early.

Weirauch Farm’s production slowed substantially late last fall, when their supply of milk was interrupted by a large dairy that contracted with their supplier. Six other Bay Area cheese makers found themselves in the same situation, without the milk to make their hand-crafted cheeses.

“We’re all so small,” Carleen  Weirauch explains, “that we cannot compete contract-wise with larger companies.”

If a large producer wants all the milk, what’s a dairy to do but sell it to them?

Recently, Weirauch Farm entered into a contract with Nicasio Valley Farms, the Lafranchi Family’s ranch, with a herd of more than 400 cows. Most of the milk is sold to Clover but Weirauch has been granted a six-month contract for 140 gallons of milk a week.

Buying a small amount of milk seems to be getting tricker all the time but cheese makers are limited by the size of their vat or vats. Weirauch Farm’s single vat holds just 70 gallons.

The smaller the vat, the harder it is to find, it seems. Carleen and Joel Weirauch found their vat, which was refurbished, on the East Coast. They’ve ordered a new one, with a capacity of 200-gallons, from a manufacturer in Europe but it won’t arrive until mid to late summer.

Even a 500-gallon vat is considered small. A vat is a cheese maker’s major investment.

Once you have the vat, you need milk and if you do not have your own herd or flock, it can be hard to get it. Weirauch Farm has sheep and makes its signature cheese, the raw-milk Saint Rose, using their own milk. But it is a seasonal endeavor and lambing season has just begun. Currently, they are also able to buy a small amount of sheep’s milk from Williams Ranches in Sebastopol, which allows them to offer a selection of sheep’s milk cheeses instead of just one.

Weirauch Farm & Creamery first appeared at the Sebastopol Farmers Market several years ago, when they were building their creamery and selling only their wonderful sheep’s milk soap. Over a few seasons, I learned of their plans, tasted several of Joel Weirauch’s test batches of cheese and yogurt and eagerly awaited their commercial production. Everyone who knew them was thrilled when they added a selection of delicious cow’s milk cheeses. Their sheep’s milk cheeses are one of our great seasonal delights; don’t miss them!

Weirauch Farm & Creamery, founded in 2004 and owner and operated by Carleen and Joel Weirauch, attends the Santa Rosa Original Certified Farmers Market (50 Mark West Springs Rd.) on Saturday and the Sebastopol Farmers Market on Sunday. The farm also attends two other farmers markets, not in Sonoma County. To order full rounds of cheese, call 347-9401.